Release 4.13 mm/hugetlb.c

Directory: mm
/*
 * Generic hugetlb support.
 * (C) Nadia Yvette Chambers, April 2004
 */
#include <linux/list.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/seq_file.h>
#include <linux/sysctl.h>
#include <linux/highmem.h>
#include <linux/mmu_notifier.h>
#include <linux/nodemask.h>
#include <linux/pagemap.h>
#include <linux/mempolicy.h>
#include <linux/compiler.h>
#include <linux/cpuset.h>
#include <linux/mutex.h>
#include <linux/bootmem.h>
#include <linux/sysfs.h>
#include <linux/slab.h>
#include <linux/sched/signal.h>
#include <linux/rmap.h>
#include <linux/string_helpers.h>
#include <linux/swap.h>
#include <linux/swapops.h>
#include <linux/jhash.h>

#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/tlb.h>

#include <linux/io.h>
#include <linux/hugetlb.h>
#include <linux/hugetlb_cgroup.h>
#include <linux/node.h>
#include <linux/userfaultfd_k.h>
#include "internal.h"


int hugepages_treat_as_movable;


int hugetlb_max_hstate __read_mostly;

unsigned int default_hstate_idx;

struct hstate hstates[HUGE_MAX_HSTATE];
/*
 * Minimum page order among possible hugepage sizes, set to a proper value
 * at boot time.
 */

static unsigned int minimum_order __read_mostly = UINT_MAX;

__initdata LIST_HEAD(huge_boot_pages);

/* for command line parsing */

static struct hstate * __initdata parsed_hstate;

static unsigned long __initdata default_hstate_max_huge_pages;

static unsigned long __initdata default_hstate_size;

static bool __initdata parsed_valid_hugepagesz = true;

/*
 * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages,
 * free_huge_pages, and surplus_huge_pages.
 */

DEFINE_SPINLOCK(hugetlb_lock);

/*
 * Serializes faults on the same logical page.  This is used to
 * prevent spurious OOMs when the hugepage pool is fully utilized.
 */

static int num_fault_mutexes;

struct mutex *hugetlb_fault_mutex_table ____cacheline_aligned_in_smp;

/* Forward declaration */
static int hugetlb_acct_memory(struct hstate *h, long delta);



static inline void unlock_or_release_subpool(struct hugepage_subpool *spool)
{
	bool free = (spool->count == 0) && (spool->used_hpages == 0);

	spin_unlock(&spool->lock);

	/* If no pages are used, and no other handles to the subpool
         * remain, give up any reservations mased on minimum size and
         * free the subpool */
	if (free) {
		if (spool->min_hpages != -1)
			hugetlb_acct_memory(spool->hstate,
						-spool->min_hpages);
		kfree(spool);
	}
}

Contributors
Person Tokens Prop Commits CommitProp
David Gibson 48 66.67% 1 50.00%
Mike Kravetz 24 33.33% 1 50.00%
Total 72 100.00% 2 100.00%



struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages,
						long min_hpages)
{
	struct hugepage_subpool *spool;

	spool = kzalloc(sizeof(*spool), GFP_KERNEL);
	if (!spool)
		return NULL;

	spin_lock_init(&spool->lock);
	spool->count = 1;
	spool->max_hpages = max_hpages;
	spool->hstate = h;
	spool->min_hpages = min_hpages;

	if (min_hpages != -1 && hugetlb_acct_memory(h, min_hpages)) {
		kfree(spool);
		return NULL;
	}
	spool->rsv_hpages = min_hpages;

	return spool;
}

Contributors
Person Tokens Prop Commits CommitProp
David Gibson 56 51.38% 1 33.33%
Mike Kravetz 53 48.62% 2 66.67%
Total 109 100.00% 3 100.00%



void hugepage_put_subpool(struct hugepage_subpool *spool)
{
	spin_lock(&spool->lock);
	BUG_ON(!spool->count);
	spool->count--;
	unlock_or_release_subpool(spool);
}

Contributors
Person Tokens Prop Commits CommitProp
David Gibson 36 100.00% 1 100.00%
Total 36 100.00% 1 100.00%

/*
 * Subpool accounting for allocating and reserving pages.
 * Return -ENOMEM if there are not enough resources to satisfy the
 * the request.  Otherwise, return the number of pages by which the
 * global pools must be adjusted (upward).  The returned value may
 * only be different than the passed value (delta) in the case where
 * a subpool minimum size must be manitained.
 */


static long hugepage_subpool_get_pages(struct hugepage_subpool *spool,
				      long delta)
{
	long ret = delta;

	if (!spool)
		return ret;

	spin_lock(&spool->lock);

	if (spool->max_hpages != -1) {		/* maximum size accounting */
		if ((spool->used_hpages + delta) <= spool->max_hpages)
			spool->used_hpages += delta;
		else {
			ret = -ENOMEM;
			goto unlock_ret;
		}
	}

	/* minimum size accounting */
	if (spool->min_hpages != -1 && spool->rsv_hpages) {
		if (delta > spool->rsv_hpages) {
			/*
                         * Asking for more reserves than those already taken on
                         * behalf of subpool.  Return difference.
                         */
			ret = delta - spool->rsv_hpages;
			spool->rsv_hpages = 0;
		} else {
			ret = 0;	/* reserves already accounted for */
			spool->rsv_hpages -= delta;
		}
	}

unlock_ret:
	spin_unlock(&spool->lock);
	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Kravetz 76 52.05% 2 66.67%
David Gibson 70 47.95% 1 33.33%
Total 146 100.00% 3 100.00%

/*
 * Subpool accounting for freeing and unreserving pages.
 * Return the number of global page reservations that must be dropped.
 * The return value may only be different than the passed value (delta)
 * in the case where a subpool minimum size must be maintained.
 */


static long hugepage_subpool_put_pages(struct hugepage_subpool *spool,
				       long delta)
{
	long ret = delta;

	if (!spool)
		return delta;

	spin_lock(&spool->lock);

	if (spool->max_hpages != -1)		/* maximum size accounting */
		spool->used_hpages -= delta;

	 /* minimum size accounting */
	if (spool->min_hpages != -1 && spool->used_hpages < spool->min_hpages) {
		if (spool->rsv_hpages + delta <= spool->min_hpages)
			ret = 0;
		else
			ret = spool->rsv_hpages + delta - spool->min_hpages;

		spool->rsv_hpages += delta;
		if (spool->rsv_hpages > spool->min_hpages)
			spool->rsv_hpages = spool->min_hpages;
	}

	/*
         * If hugetlbfs_put_super couldn't free spool due to an outstanding
         * quota reference, free it now.
         */
	unlock_or_release_subpool(spool);

	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Kravetz 96 72.18% 2 66.67%
David Gibson 37 27.82% 1 33.33%
Total 133 100.00% 3 100.00%



static inline struct hugepage_subpool *subpool_inode(struct inode *inode)
{
	return HUGETLBFS_SB(inode->i_sb)->spool;
}

Contributors
Person Tokens Prop Commits CommitProp
David Gibson 24 100.00% 1 100.00%
Total 24 100.00% 1 100.00%



static inline struct hugepage_subpool *subpool_vma(struct vm_area_struct *vma)
{
	return subpool_inode(file_inode(vma->vm_file));
}

Contributors
Person Tokens Prop Commits CommitProp
David Gibson 22 88.00% 1 50.00%
Al Viro 3 12.00% 1 50.00%
Total 25 100.00% 2 100.00%

/*
 * Region tracking -- allows tracking of reservations and instantiated pages
 *                    across the pages in a mapping.
 *
 * The region data structures are embedded into a resv_map and protected
 * by a resv_map's lock.  The set of regions within the resv_map represent
 * reservations for huge pages, or huge pages that have already been
 * instantiated within the map.  The from and to elements are huge page
 * indicies into the associated mapping.  from indicates the starting index
 * of the region.  to represents the first index past the end of  the region.
 *
 * For example, a file region structure with from == 0 and to == 4 represents
 * four huge pages in a mapping.  It is important to note that the to element
 * represents the first element past the end of the region. This is used in
 * arithmetic as 4(to) - 0(from) = 4 huge pages in the region.
 *
 * Interval notation of the form [from, to) will be used to indicate that
 * the endpoint from is inclusive and to is exclusive.
 */

struct file_region {
	
struct list_head link;
	
long from;
	
long to;
};

/*
 * Add the huge page range represented by [f, t) to the reserve
 * map.  In the normal case, existing regions will be expanded
 * to accommodate the specified range.  Sufficient regions should
 * exist for expansion due to the previous call to region_chg
 * with the same range.  However, it is possible that region_del
 * could have been called after region_chg and modifed the map
 * in such a way that no region exists to be expanded.  In this
 * case, pull a region descriptor from the cache associated with
 * the map and use that for the new range.
 *
 * Return the number of new huge pages added to the map.  This
 * number is greater than or equal to zero.
 */


static long region_add(struct resv_map *resv, long f, long t)
{
	struct list_head *head = &resv->regions;
	struct file_region *rg, *nrg, *trg;
	long add = 0;

	spin_lock(&resv->lock);
	/* Locate the region we are either in or before. */
	list_for_each_entry(rg, head, link)
		if (f <= rg->to)
			break;

	/*
         * If no region exists which can be expanded to include the
         * specified range, the list must have been modified by an
         * interleving call to region_del().  Pull a region descriptor
         * from the cache and use it for this range.
         */
	if (&rg->link == head || t < rg->from) {
		VM_BUG_ON(resv->region_cache_count <= 0);

		resv->region_cache_count--;
		nrg = list_first_entry(&resv->region_cache, struct file_region,
					link);
		list_del(&nrg->link);

		nrg->from = f;
		nrg->to = t;
		list_add(&nrg->link, rg->link.prev);

		add += t - f;
		goto out_locked;
	}

	/* Round our left edge to the current segment if it encloses us. */
	if (f > rg->from)
		f = rg->from;

	/* Check for and consume any regions we now overlap with. */
	nrg = rg;
	list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
		if (&rg->link == head)
			break;
		if (rg->from > t)
			break;

		/* If this area reaches higher then extend our area to
                 * include it completely.  If this is not the first area
                 * which we intend to reuse, free it. */
		if (rg->to > t)
			t = rg->to;
		if (rg != nrg) {
			/* Decrement return value by the deleted range.
                         * Another range will span this area so that by
                         * end of routine add will be >= zero
                         */
			add -= (rg->to - rg->from);
			list_del(&rg->link);
			kfree(rg);
		}
	}

	add += (nrg->from - f);		/* Added to beginning of region */
	nrg->from = f;
	add += t - nrg->to;		/* Added to end of region */
	nrg->to = t;

out_locked:
	resv->adds_in_progress--;
	spin_unlock(&resv->lock);
	VM_BUG_ON(add < 0);
	return add;
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Kravetz 143 45.25% 2 25.00%
Andy Whitcroft 125 39.56% 2 25.00%
Mel Gorman 20 6.33% 2 25.00%
Davidlohr Bueso A 16 5.06% 1 12.50%
JoonSoo Kim 12 3.80% 1 12.50%
Total 316 100.00% 8 100.00%

/*
 * Examine the existing reserve map and determine how many
 * huge pages in the specified range [f, t) are NOT currently
 * represented.  This routine is called before a subsequent
 * call to region_add that will actually modify the reserve
 * map to add the specified range [f, t).  region_chg does
 * not change the number of huge pages represented by the
 * map.  However, if the existing regions in the map can not
 * be expanded to represent the new range, a new file_region
 * structure is added to the map as a placeholder.  This is
 * so that the subsequent region_add call will have all the
 * regions it needs and will not fail.
 *
 * Upon entry, region_chg will also examine the cache of region descriptors
 * associated with the map.  If there are not enough descriptors cached, one
 * will be allocated for the in progress add operation.
 *
 * Returns the number of huge pages that need to be added to the existing
 * reservation map for the range [f, t).  This number is greater or equal to
 * zero.  -ENOMEM is returned if a new file_region structure or cache entry
 * is needed and can not be allocated.
 */


static long region_chg(struct resv_map *resv, long f, long t)
{
	struct list_head *head = &resv->regions;
	struct file_region *rg, *nrg = NULL;
	long chg = 0;

retry:
	spin_lock(&resv->lock);
retry_locked:
	resv->adds_in_progress++;

	/*
         * Check for sufficient descriptors in the cache to accommodate
         * the number of in progress add operations.
         */
	if (resv->adds_in_progress > resv->region_cache_count) {
		struct file_region *trg;

		VM_BUG_ON(resv->adds_in_progress - resv->region_cache_count > 1);
		/* Must drop lock to allocate a new descriptor. */
		resv->adds_in_progress--;
		spin_unlock(&resv->lock);

		trg = kmalloc(sizeof(*trg), GFP_KERNEL);
		if (!trg) {
			kfree(nrg);
			return -ENOMEM;
		}

		spin_lock(&resv->lock);
		list_add(&trg->link, &resv->region_cache);
		resv->region_cache_count++;
		goto retry_locked;
	}

	/* Locate the region we are before or in. */
	list_for_each_entry(rg, head, link)
		if (f <= rg->to)
			break;

	/* If we are below the current region then a new region is required.
         * Subtle, allocate a new region at the position but make it zero
         * size such that we can guarantee to record the reservation. */
	if (&rg->link == head || t < rg->from) {
		if (!nrg) {
			resv->adds_in_progress--;
			spin_unlock(&resv->lock);
			nrg = kmalloc(sizeof(*nrg), GFP_KERNEL);
			if (!nrg)
				return -ENOMEM;

			nrg->from = f;
			nrg->to   = f;
			INIT_LIST_HEAD(&nrg->link);
			goto retry;
		}

		list_add(&nrg->link, rg->link.prev);
		chg = t - f;
		goto out_nrg;
	}

	/* Round our left edge to the current segment if it encloses us. */
	if (f > rg->from)
		f = rg->from;
	chg = t - f;

	/* Check for and consume any regions we now overlap with. */
	list_for_each_entry(rg, rg->link.prev, link) {
		if (&rg->link == head)
			break;
		if (rg->from > t)
			goto out;

		/* We overlap with this area, if it extends further than
                 * us then we must extend ourselves.  Account for its
                 * existing reservation. */
		if (rg->to > t) {
			chg += rg->to - t;
			t = rg->to;
		}
		chg -= rg->to - rg->from;
	}

out:
	spin_unlock(&resv->lock);
	/*  We already know we raced and no longer need the new region */
	kfree(nrg);
	return chg;
out_nrg:
	spin_unlock(&resv->lock);
	return chg;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 164 40.39% 1 11.11%
Mike Kravetz 115 28.33% 2 22.22%
Davidlohr Bueso A 68 16.75% 1 11.11%
Mel Gorman 41 10.10% 2 22.22%
JoonSoo Kim 12 2.96% 1 11.11%
David Gibson 5 1.23% 1 11.11%
Lucas De Marchi 1 0.25% 1 11.11%
Total 406 100.00% 9 100.00%

/*
 * Abort the in progress add operation.  The adds_in_progress field
 * of the resv_map keeps track of the operations in progress between
 * calls to region_chg and region_add.  Operations are sometimes
 * aborted after the call to region_chg.  In such cases, region_abort
 * is called to decrement the adds_in_progress counter.
 *
 * NOTE: The range arguments [f, t) are not needed or used in this
 * routine.  They are kept to make reading the calling code easier as
 * arguments will match the associated region_chg call.
 */


static void region_abort(struct resv_map *resv, long f, long t)
{
	spin_lock(&resv->lock);
	VM_BUG_ON(!resv->region_cache_count);
	resv->adds_in_progress--;
	spin_unlock(&resv->lock);
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Kravetz 46 100.00% 1 100.00%
Total 46 100.00% 1 100.00%

/*
 * Delete the specified range [f, t) from the reserve map.  If the
 * t parameter is LONG_MAX, this indicates that ALL regions after f
 * should be deleted.  Locate the regions which intersect [f, t)
 * and either trim, delete or split the existing regions.
 *
 * Returns the number of huge pages deleted from the reserve map.
 * In the normal case, the return value is zero or more.  In the
 * case where a region must be split, a new region descriptor must
 * be allocated.  If the allocation fails, -ENOMEM will be returned.
 * NOTE: If the parameter t == LONG_MAX, then we will never split
 * a region and possibly return -ENOMEM.  Callers specifying
 * t == LONG_MAX do not need to check for -ENOMEM error.
 */


static long region_del(struct resv_map *resv, long f, long t)
{
	struct list_head *head = &resv->regions;
	struct file_region *rg, *trg;
	struct file_region *nrg = NULL;
	long del = 0;

retry:
	spin_lock(&resv->lock);
	list_for_each_entry_safe(rg, trg, head, link) {
		/*
                 * Skip regions before the range to be deleted.  file_region
                 * ranges are normally of the form [from, to).  However, there
                 * may be a "placeholder" entry in the map which is of the form
                 * (from, to) with from == to.  Check for placeholder entries
                 * at the beginning of the range to be deleted.
                 */
		if (rg->to <= f && (rg->to != rg->from || rg->to != f))
			continue;

		if (rg->from >= t)
			break;

		if (f > rg->from && t < rg->to) { /* Must split region */
			/*
                         * Check for an entry in the cache before dropping
                         * lock and attempting allocation.
                         */
			if (!nrg &&
			    resv->region_cache_count > resv->adds_in_progress) {
				nrg = list_first_entry(&resv->region_cache,
							struct file_region,
							link);
				list_del(&nrg->link);
				resv->region_cache_count--;
			}

			if (!nrg) {
				spin_unlock(&resv->lock);
				nrg = kmalloc(sizeof(*nrg), GFP_KERNEL);
				if (!nrg)
					return -ENOMEM;
				goto retry;
			}

			del += t - f;

			/* New entry for end of split region */
			nrg->from = t;
			nrg->to = rg->to;
			INIT_LIST_HEAD(&nrg->link);

			/* Original entry is trimmed */
			rg->to = f;

			list_add(&nrg->link, &rg->link);
			nrg = NULL;
			break;
		}

		if (f <= rg->from && t >= rg->to) { /* Remove entire region */
			del += rg->to - rg->from;
			list_del(&rg->link);
			kfree(rg);
			continue;
		}

		if (f <= rg->from) {	/* Trim beginning of region */
			del += t - rg->from;
			rg->from = t;
		} else {		/* Trim end of region */
			del += rg->to - f;
			rg->to = f;
		}
	}

	spin_unlock(&resv->lock);
	kfree(nrg);
	return del;
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Kravetz 234 65.18% 2 28.57%
Andy Whitcroft 65 18.11% 1 14.29%
David Gibson 17 4.74% 1 14.29%
Davidlohr Bueso A 16 4.46% 1 14.29%
Nishanth Aravamudan 15 4.18% 1 14.29%
JoonSoo Kim 12 3.34% 1 14.29%
Total 359 100.00% 7 100.00%

/*
 * A rare out of memory error was encountered which prevented removal of
 * the reserve map region for a page.  The huge page itself was free'ed
 * and removed from the page cache.  This routine will adjust the subpool
 * usage count, and the global reserve count if needed.  By incrementing
 * these counts, the reserve map entry which could not be deleted will
 * appear as a "reserved" entry instead of simply dangling with incorrect
 * counts.
 */


void hugetlb_fix_reserve_counts(struct inode *inode)
{
	struct hugepage_subpool *spool = subpool_inode(inode);
	long rsv_adjust;

	rsv_adjust = hugepage_subpool_get_pages(spool, 1);
	if (rsv_adjust) {
		struct hstate *h = hstate_inode(inode);

		hugetlb_acct_memory(h, 1);
	}
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Kravetz 55 100.00% 1 100.00%
Total 55 100.00% 1 100.00%

/*
 * Count and return the number of huge pages in the reserve map
 * that intersect with the range [f, t).
 */


static long region_count(struct resv_map *resv, long f, long t)
{
	struct list_head *head = &resv->regions;
	struct file_region *rg;
	long chg = 0;

	spin_lock(&resv->lock);
	/* Locate each segment we overlap with, and count that overlap. */
	list_for_each_entry(rg, head, link) {
		long seg_from;
		long seg_to;

		if (rg->to <= f)
			continue;
		if (rg->from >= t)
			break;

		seg_from = max(rg->from, f);
		seg_to = min(rg->to, t);

		chg += seg_to - seg_from;
	}
	spin_unlock(&resv->lock);

	return chg;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 89 74.79% 1 25.00%
Davidlohr Bueso A 16 13.45% 1 25.00%
JoonSoo Kim 12 10.08% 1 25.00%
Wang Sheng-Hui 2 1.68% 1 25.00%
Total 119 100.00% 4 100.00%

/*
 * Convert the address within this vma to the page offset within
 * the mapping, in pagecache page units; huge pages here.
 */


static pgoff_t vma_hugecache_offset(struct hstate *h,
			struct vm_area_struct *vma, unsigned long address)
{
	return ((address - vma->vm_start) >> huge_page_shift(h)) +
			(vma->vm_pgoff >> huge_page_order(h));
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 27 57.45% 1 14.29%
Andi Kleen 13 27.66% 1 14.29%
Christoph Lameter 3 6.38% 2 28.57%
Mel Gorman 2 4.26% 1 14.29%
Johannes Weiner 1 2.13% 1 14.29%
Lee Schermerhorn 1 2.13% 1 14.29%
Total 47 100.00% 7 100.00%



pgoff_t linear_hugepage_index(struct vm_area_struct *vma,
				     unsigned long address)
{
	return vma_hugecache_offset(hstate_vma(vma), vma, address);
}
Contributors
Person Tokens Prop Commits CommitProp
Naoya Horiguchi 27 100.00% 1 100.00%
Total 27 100.00% 1 100.00%


EXPORT_SYMBOL_GPL(linear_hugepage_index);

/*
 * Return the size of the pages allocated when backing a VMA. In the majority
 * cases this will be same size as used by the page table entries.
 */


unsigned long vma_kernel_pagesize(struct vm_area_struct *vma)
{
	struct hstate *hstate;

	if (!is_vm_hugetlb_page(vma))
		return PAGE_SIZE;

	hstate = hstate_vma(vma);

	return 1UL << huge_page_shift(hstate);
}
Contributors
Person Tokens Prop Commits CommitProp
Mel Gorman 39 92.86% 1 50.00%
Wanpeng Li 3 7.14% 1 50.00%
Total 42 100.00% 2 100.00%


EXPORT_SYMBOL_GPL(vma_kernel_pagesize);

/*
 * Return the page size being used by the MMU to back a VMA. In the majority
 * of cases, the page size used by the kernel matches the MMU size. On
 * architectures where it differs, an architecture-specific version of this
 * function is required.
 */
#ifndef vma_mmu_pagesize


unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
{
	return vma_kernel_pagesize(vma);
}
Contributors
Person Tokens Prop Commits CommitProp
Mel Gorman 17 100.00% 1 100.00%
Total 17 100.00% 1 100.00%

#endif

/*
 * Flags for MAP_PRIVATE reservations.  These are stored in the bottom
 * bits of the reservation map pointer, which are always clear due to
 * alignment.
 */

#define HPAGE_RESV_OWNER    (1UL << 0)

#define HPAGE_RESV_UNMAPPED (1UL << 1)

#define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED)

/*
 * These helpers are used to track how many pages are reserved for
 * faults in a MAP_PRIVATE mapping. Only the process that called mmap()
 * is guaranteed to have their future faults succeed.
 *
 * With the exception of reset_vma_resv_huge_pages() which is called at fork(),
 * the reserve counters are updated with the hugetlb_lock held. It is safe
 * to reset the VMA at fork() time as it is not in use yet and there is no
 * chance of the global counters getting corrupted as a result of the values.
 *
 * The private mapping reservation is represented in a subtly different
 * manner to a shared mapping.  A shared mapping has a region map associated
 * with the underlying file, this region map represents the backing file
 * pages which have ever had a reservation assigned which this persists even
 * after the page is instantiated.  A private mapping has a region map
 * associated with the original mmap which is attached to all VMAs which
 * reference it, this region map represents those offsets which have consumed
 * reservation ie. where pages have been instantiated.
 */


static unsigned long get_vma_private_data(struct vm_area_struct *vma)
{
	return (unsigned long)vma->vm_private_data;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 19 90.48% 1 50.00%
Mel Gorman 2 9.52% 1 50.00%
Total 21 100.00% 2 100.00%



static void set_vma_private_data(struct vm_area_struct *vma,
							unsigned long value)
{
	vma->vm_private_data = (void *)value;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 22 88.00% 1 50.00%
Christoph Lameter 3 12.00% 1 50.00%
Total 25 100.00% 2 100.00%



struct resv_map *resv_map_alloc(void)
{
	struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL);
	struct file_region *rg = kmalloc(sizeof(*rg), GFP_KERNEL);

	if (!resv_map || !rg) {
		kfree(resv_map);
		kfree(rg);
		return NULL;
	}

	kref_init(&resv_map->refs);
	spin_lock_init(&resv_map->lock);
	INIT_LIST_HEAD(&resv_map->regions);

	resv_map->adds_in_progress = 0;

	INIT_LIST_HEAD(&resv_map->region_cache);
	list_add(&rg->link, &resv_map->region_cache);
	resv_map->region_cache_count = 1;

	return resv_map;
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Kravetz 64 51.61% 1 33.33%
Andy Whitcroft 52 41.94% 1 33.33%
Davidlohr Bueso A 8 6.45% 1 33.33%
Total 124 100.00% 3 100.00%



void resv_map_release(struct kref *ref)
{
	struct resv_map *resv_map = container_of(ref, struct resv_map, refs);
	struct list_head *head = &resv_map->region_cache;
	struct file_region *rg, *trg;

	/* Clear out any active regions before we release the map. */
	region_del(resv_map, 0, LONG_MAX);

	/* ... and any entries left in the cache */
	list_for_each_entry_safe(rg, trg, head, link) {
		list_del(&rg->link);
		kfree(rg);
	}

	VM_BUG_ON(resv_map->adds_in_progress);

	kfree(resv_map);
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Kravetz 54 59.34% 2 66.67%
Andy Whitcroft 37 40.66% 1 33.33%
Total 91 100.00% 3 100.00%



static inline struct resv_map *inode_resv_map(struct inode *inode)
{
	return inode->i_mapping->private_data;
}

Contributors
Person Tokens Prop Commits CommitProp
JoonSoo Kim 21 100.00% 1 100.00%
Total 21 100.00% 1 100.00%



static struct resv_map *vma_resv_map(struct vm_area_struct *vma)
{
	VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma);
	if (vma->vm_flags & VM_MAYSHARE) {
		struct address_space *mapping = vma->vm_file->f_mapping;
		struct inode *inode = mapping->host;

		return inode_resv_map(inode);

	} else {
		return (struct resv_map *)(get_vma_private_data(vma) &
							~HPAGE_RESV_MASK);
	}
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 31 39.24% 2 22.22%
JoonSoo Kim 31 39.24% 1 11.11%
Mel Gorman 7 8.86% 3 33.33%
Andrew Morton 6 7.59% 1 11.11%
Sasha Levin 3 3.80% 1 11.11%
Christoph Lameter 1 1.27% 1 11.11%
Total 79 100.00% 9 100.00%



static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map)
{
	VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma);
	VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma);

	set_vma_private_data(vma, (get_vma_private_data(vma) &
				HPAGE_RESV_MASK) | (unsigned long)map);
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 31 53.45% 2 33.33%
Adam Litke 17 29.31% 1 16.67%
Sasha Levin 6 10.34% 1 16.67%
Gerald Schaefer 3 5.17% 1 16.67%
Mel Gorman 1 1.72% 1 16.67%
Total 58 100.00% 6 100.00%



static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags)
{
	VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma);
	VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma);

	set_vma_private_data(vma, get_vma_private_data(vma) | flags);
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 26 53.06% 2 28.57%
David Gibson 12 24.49% 1 14.29%
Sasha Levin 6 12.24% 1 14.29%
Adam Litke 4 8.16% 2 28.57%
Mel Gorman 1 2.04% 1 14.29%
Total 49 100.00% 7 100.00%



static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag)
{
	VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma);

	return (get_vma_private_data(vma) & flag) != 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 30 78.95% 1 33.33%
David Gibson 5 13.16% 1 33.33%
Sasha Levin 3 7.89% 1 33.33%
Total 38 100.00% 3 100.00%

/* Reset counters to 0 and clear all HPAGE_RESV_* flags */


void reset_vma_resv_huge_pages(struct vm_area_struct *vma)
{
	VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma);
	if (!(vma->vm_flags & VM_MAYSHARE))
		vma->vm_private_data = (void *)0;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 30 71.43% 1 20.00%
David Gibson 4 9.52% 1 20.00%
Adam Litke 4 9.52% 1 20.00%
Sasha Levin 3 7.14% 1 20.00%
Mel Gorman 1 2.38% 1 20.00%
Total 42 100.00% 5 100.00%

/* Returns true if the VMA has associated reserve pages */


static bool vma_has_reserves(struct vm_area_struct *vma, long chg)
{
	if (vma->vm_flags & VM_NORESERVE) {
		/*
                 * This address is already reserved by other process(chg == 0),
                 * so, we should decrement reserved count. Without decrementing,
                 * reserve count remains after releasing inode, because this
                 * allocated page will go into page cache and is regarded as
                 * coming from reserved pool in releasing step.  Currently, we
                 * don't have any other solution to deal with this situation
                 * properly, so add work-around here.
                 */
		if (vma->vm_flags & VM_MAYSHARE && chg == 0)
			return true;
		else
			return false;
	}

	/* Shared mappings always use reserves */
	if (vma->vm_flags & VM_MAYSHARE) {
		/*
                 * We know VM_NORESERVE is not set.  Therefore, there SHOULD
                 * be a region map for all pages.  The only situation where
                 * there is no region map is if a hole was punched via
                 * fallocate.  In this case, there really are no reverves to
                 * use.  This situation is indicated if chg != 0.
                 */
		if (chg)
			return false;
		else
			return true;
	}

	/*
         * Only the process that called mmap() has reserves for
         * private mappings.
         */
	if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
		/*
                 * Like the shared case above, a hole punch or truncate
                 * could have been performed on the private mapping.
                 * Examine the value of chg to determine if reserves
                 * actually exist or were previously consumed.
                 * Very Subtle - The value of chg comes from a previous
                 * call to vma_needs_reserves().  The reserve map for
                 * private mappings has different (opposite) semantics
                 * than that of shared mappings.  vma_needs_reserves()
                 * has already taken this difference in semantics into
                 * account.  Therefore, the meaning of chg is the same
                 * as in the shared case above.  Code could easily be
                 * combined, but keeping it separate draws attention to
                 * subtle differences.
                 */
		if (chg)
			return false;
		else
			return true;
	}

	return false;
}

Contributors
Person Tokens Prop Commits CommitProp
JoonSoo Kim 33 35.11% 3 27.27%
Mike Kravetz 22 23.40% 2 18.18%
Andy Whitcroft 18 19.15% 2 18.18%
Adam Litke 13 13.83% 1 9.09%
Nicholas Krause 6 6.38% 1 9.09%
Mel Gorman 2 2.13% 2 18.18%
Total 94 100.00% 11 100.00%



static void enqueue_huge_page(struct hstate *h, struct page *page)
{
	int nid = page_to_nid(page);
	list_move(&page->lru, &h->hugepage_freelists[nid]);
	h->free_huge_pages++;
	h->free_huge_pages_node[nid]++;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 23 43.40% 2 22.22%
Andi Kleen 11 20.75% 1 11.11%
Kenneth W. Chen 8 15.09% 1 11.11%
Gerald Schaefer 5 9.43% 1 11.11%
Eric Paris 3 5.66% 1 11.11%
Aneesh Kumar K.V 1 1.89% 1 11.11%
Nicholas Piggin 1 1.89% 1 11.11%
Nishanth Aravamudan 1 1.89% 1 11.11%
Total 53 100.00% 9 100.00%



static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid)
{
	struct page *page;

	list_for_each_entry(page, &h->hugepage_freelists[nid], lru)
		if (!PageHWPoison(page))
			break;
	/*
         * if 'non-isolated free hugepage' not found on the list,
         * the allocation fails.
         */
	if (&h->hugepage_freelists[nid] == &page->lru)
		return NULL;
	list_move(&page->lru, &h->hugepage_activelist);
	set_page_refcounted(page);
	h->free_huge_pages--;
	h->free_huge_pages_node[nid]--;
	return page;
}

Contributors
Person Tokens Prop Commits CommitProp
Naoya Horiguchi 84 92.31% 4 66.67%
Aneesh Kumar K.V 6 6.59% 1 16.67%
Anshuman Khandual 1 1.10% 1 16.67%
Total 91 100.00% 6 100.00%



static struct page *dequeue_huge_page_nodemask(struct hstate *h, gfp_t gfp_mask, int nid,
		nodemask_t *nmask)
{
	unsigned int cpuset_mems_cookie;
	struct zonelist *zonelist;
	struct zone *zone;
	struct zoneref *z;
	int node = -1;

	zonelist = node_zonelist(nid, gfp_mask);

retry_cpuset:
	cpuset_mems_cookie = read_mems_allowed_begin();
	for_each_zone_zonelist_nodemask(zone, z, zonelist, gfp_zone(gfp_mask), nmask) {
		struct page *page;

		if (!cpuset_zone_allowed(zone, gfp_mask))
			continue;
		/*
                 * no need to ask again on the same node. Pool is node rather than
                 * zone aware
                 */
		if (zone_to_nid(zone) == node)
			continue;
		node = zone_to_nid(zone);

		page = dequeue_huge_page_node_exact(h, node);
		if (page)
			return page;
	}
	if (unlikely(read_mems_allowed_retry(cpuset_mems_cookie)))
		goto retry_cpuset;

	return NULL;
}

Contributors
Person Tokens Prop Commits CommitProp
Michal Hocko 96 66.67% 1 50.00%
Anshuman Khandual 48 33.33% 1 50.00%
Total 144 100.00% 2 100.00%

/* Movability of hugepages depends on migration support. */


static inline gfp_t htlb_alloc_mask(struct hstate *h)
{
	if (hugepages_treat_as_movable || hugepage_migration_supported(h))
		return GFP_HIGHUSER_MOVABLE;
	else
		return GFP_HIGHUSER;
}

Contributors
Person Tokens Prop Commits CommitProp
Naoya Horiguchi 28 100.00% 2 100.00%
Total 28 100.00% 2 100.00%



static struct page *dequeue_huge_page_vma(struct hstate *h,
				struct vm_area_struct *vma,
				unsigned long address, int avoid_reserve,
				long chg)
{
	struct page *page;
	struct mempolicy *mpol;
	gfp_t gfp_mask;
	nodemask_t *nodemask;
	int nid;

	/*
         * A child process with MAP_PRIVATE mappings created by their parent
         * have no page reserves. This check ensures that reservations are
         * not "stolen". The child may still get SIGKILLed
         */
	if (!vma_has_reserves(vma, chg) &&
			h->free_huge_pages - h->resv_huge_pages == 0)
		goto err;

	/* If reserves cannot be used, ensure enough pages are in the pool */
	if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0)
		goto err;

	gfp_mask = htlb_alloc_mask(h);
	nid = huge_node(vma, address, gfp_mask, &mpol, &nodemask);
	page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask);
	if (page && !avoid_reserve && vma_has_reserves(vma, chg)) {
		SetPagePrivate(page);
		h->resv_huge_pages--;
	}

	mpol_cond_put(mpol);
	return page;

err:
	return NULL;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 35 21.08% 1 6.67%
JoonSoo Kim 33 19.88% 4 26.67%
Adam Litke 31 18.67% 2 13.33%
Vlastimil Babka 17 10.24% 1 6.67%
Andi Kleen 13 7.83% 1 6.67%
Michal Hocko 12 7.23% 1 6.67%
Mel Gorman 8 4.82% 2 13.33%
Miao Xie 8 4.82% 1 6.67%
Nishanth Aravamudan 5 3.01% 1 6.67%
Naoya Horiguchi 4 2.41% 1 6.67%
Total 166 100.00% 15 100.00%

/*
 * common helper functions for hstate_next_node_to_{alloc|free}.
 * We may have allocated or freed a huge page based on a different
 * nodes_allowed previously, so h->next_node_to_{alloc|free} might
 * be outside of *nodes_allowed.  Ensure that we use an allowed
 * node for alloc or free.
 */


static int next_node_allowed(int nid, nodemask_t *nodes_allowed)
{
	nid = next_node_in(nid, *nodes_allowed);
	VM_BUG_ON(nid >= MAX_NUMNODES);

	return nid;
}

Contributors
Person Tokens Prop Commits CommitProp
Luiz Fernando N. Capitulino 32 96.97% 1 50.00%
Andrew Morton 1 3.03% 1 50.00%
Total 33 100.00% 2 100.00%



static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed)
{
	if (!node_isset(nid, *nodes_allowed))
		nid = next_node_allowed(nid, nodes_allowed);
	return nid;
}

Contributors
Person Tokens Prop Commits CommitProp
Luiz Fernando N. Capitulino 36 100.00% 1 100.00%
Total 36 100.00% 1 100.00%

/*
 * returns the previously saved node ["this node"] from which to
 * allocate a persistent huge page for the pool and advance the
 * next node from which to allocate, handling wrap at end of node
 * mask.
 */


static int hstate_next_node_to_alloc(struct hstate *h,
					nodemask_t *nodes_allowed)
{
	int nid;

	VM_BUG_ON(!nodes_allowed);

	nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed);
	h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed);

	return nid;
}

Contributors
Person Tokens Prop Commits CommitProp
Luiz Fernando N. Capitulino 49 100.00% 1 100.00%
Total 49 100.00% 1 100.00%

/*
 * helper for free_pool_huge_page() - return the previously saved
 * node ["this node"] from which to free a huge page.  Advance the
 * next node id whether or not we find a free huge page to free so
 * that the next attempt to free addresses the next node.
 */


static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed)
{
	int nid;

	VM_BUG_ON(!nodes_allowed);

	nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed);
	h->next_nid_to_free = next_node_allowed(nid, nodes_allowed);

	return nid;
}

Contributors
Person Tokens Prop Commits CommitProp
Luiz Fernando N. Capitulino 49 100.00% 1 100.00%
Total 49 100.00% 1 100.00%


#define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask)		\
	for (nr_nodes = nodes_weight(*mask);                            \
                nr_nodes > 0 &&                                         \
                ((node = hstate_next_node_to_alloc(hs, mask)) || 1);    \
                nr_nodes--)


#define for_each_node_mask_to_free(hs, nr_nodes, node, mask)		\
	for (nr_nodes = nodes_weight(*mask);                            \
                nr_nodes > 0 &&                                         \
                ((node = hstate_next_node_to_free(hs, mask)) || 1);     \
                nr_nodes--)

#ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE


static void destroy_compound_gigantic_page(struct page *page,
					unsigned int order)
{
	int i;
	int nr_pages = 1 << order;
	struct page *p = page + 1;

	atomic_set(compound_mapcount_ptr(page), 0);
	for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) {
		clear_compound_head(p);
		set_page_refcounted(p);
	}

	set_compound_order(page, 0);
	__ClearPageHead(page);
}

Contributors
Person Tokens Prop Commits CommitProp
Luiz Fernando N. Capitulino 80 86.96% 1 25.00%
Gerald Schaefer 10 10.87% 1 25.00%
Kirill A. Shutemov 2 2.17% 2 50.00%
Total 92 100.00% 4 100.00%



static void free_gigantic_page(struct page *page, unsigned int order)
{
	free_contig_range(page_to_pfn(page), 1 << order);
}

Contributors
Person Tokens Prop Commits CommitProp
Luiz Fernando N. Capitulino 26 96.30% 1 50.00%
Kirill A. Shutemov 1 3.70% 1 50.00%
Total 27 100.00% 2 100.00%



static int __alloc_gigantic_page(unsigned long start_pfn,
				unsigned long nr_pages)
{
	unsigned long end_pfn = start_pfn + nr_pages;
	return alloc_contig_range(start_pfn, end_pfn, MIGRATE_MOVABLE,
				  GFP_KERNEL);
}

Contributors
Person Tokens Prop Commits CommitProp
Luiz Fernando N. Capitulino 32 94.12% 1 50.00%
Lucas Stach 2 5.88% 1 50.00%
Total 34 100.00% 2 100.00%



static bool pfn_range_valid_gigantic(struct zone *z,
			unsigned long start_pfn, unsigned long nr_pages)
{
	unsigned long i, end_pfn = start_pfn + nr_pages;
	struct page *page;

	for (i = start_pfn; i < end_pfn; i++) {
		if (!pfn_valid(i))
			return false;

		page = pfn_to_page(i);

		if (page_zone(page) != z)
			return false;

		if (PageReserved(page))
			return false;

		if (page_count(page) > 0)
			return false;

		if (PageHuge(page))
			return false;
	}

	return true;
}

Contributors
Person Tokens Prop Commits CommitProp
Luiz Fernando N. Capitulino 97 85.09% 1 50.00%
JoonSoo Kim 17 14.91% 1 50.00%
Total 114 100.00% 2 100.00%



static bool zone_spans_last_pfn(const struct zone *zone,
			unsigned long start_pfn, unsigned long nr_pages)
{
	unsigned long last_pfn = start_pfn + nr_pages - 1;
	return zone_spans_pfn(zone, last_pfn);
}

Contributors
Person Tokens Prop Commits CommitProp
Luiz Fernando N. Capitulino 38 100.00% 1 100.00%
Total 38 100.00% 1 100.00%



static struct page *alloc_gigantic_page(int nid, unsigned int order)
{
	unsigned long nr_pages = 1 << order;
	unsigned long ret, pfn, flags;
	struct zone *z;

	z = NODE_DATA(nid)->node_zones;
	for (; z - NODE_DATA(nid)->node_zones < MAX_NR_ZONES; z++) {
		spin_lock_irqsave(&z->lock, flags);

		pfn = ALIGN(z->zone_start_pfn, nr_pages);
		while (zone_spans_last_pfn(z, pfn, nr_pages)) {
			if (pfn_range_valid_gigantic(z, pfn, nr_pages)) {
				/*
                                 * We release the zone lock here because
                                 * alloc_contig_range() will also lock the zone
                                 * at some point. If there's an allocation
                                 * spinning on this lock, it may win the race
                                 * and cause alloc_contig_range() to fail...
                                 */
				spin_unlock_irqrestore(&z->lock, flags);
				ret = __alloc_gigantic_page(pfn, nr_pages);
				if (!ret)
					return pfn_to_page(pfn);
				spin_lock_irqsave(&z->lock, flags);
			}
			pfn += nr_pages;
		}

		spin_unlock_irqrestore(&z->lock, flags);
	}

	return NULL;
}

Contributors
Person Tokens Prop Commits CommitProp
Luiz Fernando N. Capitulino 166 98.22% 1 33.33%
JoonSoo Kim 2 1.18% 1 33.33%
Kirill A. Shutemov 1 0.59% 1 33.33%
Total 169 100.00% 3 100.00%

static void prep_new_huge_page(struct hstate *h, struct page *page, int nid);
static void prep_compound_gigantic_page(struct page *page, unsigned int order);



static struct page *alloc_fresh_gigantic_page_node(struct hstate *h, int nid)
{
	struct page *page;

	page = alloc_gigantic_page(nid, huge_page_order(h));
	if (page) {
		prep_compound_gigantic_page(page, huge_page_order(h));
		prep_new_huge_page(h, page, nid);
	}

	return page;
}

Contributors
Person Tokens Prop Commits CommitProp
Luiz Fernando N. Capitulino 61 100.00% 1 100.00%
Total 61 100.00% 1 100.00%



static int alloc_fresh_gigantic_page(struct hstate *h,
				nodemask_t *nodes_allowed)
{
	struct page *page = NULL;
	int nr_nodes, node;

	for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) {
		page = alloc_fresh_gigantic_page_node(h, node);
		if (page)
			return 1;
	}

	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Luiz Fernando N. Capitulino 58 100.00% 1 100.00%
Total 58 100.00% 1 100.00%

#else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE */


static inline bool gigantic_page_supported(void) { return false; }
Contributors
Person Tokens Prop Commits CommitProp
Luiz Fernando N. Capitulino 12 100.00% 1 100.00%
Total 12 100.00% 1 100.00%



static inline void free_gigantic_page(struct page *page, unsigned int order) { }
Contributors
Person Tokens Prop Commits CommitProp
Luiz Fernando N. Capitulino 14 93.33% 1 50.00%
Kirill A. Shutemov 1 6.67% 1 50.00%
Total 15 100.00% 2 100.00%



static inline void destroy_compound_gigantic_page(struct page *page,
						unsigned int order) { }
Contributors
Person Tokens Prop Commits CommitProp
Luiz Fernando N. Capitulino 14 93.33% 1 50.00%
Kirill A. Shutemov 1 6.67% 1 50.00%
Total 15 100.00% 2 100.00%



static inline int alloc_fresh_gigantic_page(struct hstate *h,
					nodemask_t *nodes_allowed) { return 0; }
Contributors
Person Tokens Prop Commits CommitProp
Luiz Fernando N. Capitulino 19 100.00% 1 100.00%
Total 19 100.00% 1 100.00%

#endif



static void update_and_free_page(struct hstate *h, struct page *page)
{
	int i;

	if (hstate_is_gigantic(h) && !gigantic_page_supported())
		return;

	h->nr_huge_pages--;
	h->nr_huge_pages_node[page_to_nid(page)]--;
	for (i = 0; i < pages_per_huge_page(h); i++) {
		page[i].flags &= ~(1 << PG_locked | 1 << PG_error |
				1 << PG_referenced | 1 << PG_dirty |
				1 << PG_active | 1 << PG_private |
				1 << PG_writeback);
	}
	VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page);
	set_compound_page_dtor(page, NULL_COMPOUND_DTOR);
	set_page_refcounted(page);
	if (hstate_is_gigantic(h)) {
		destroy_compound_gigantic_page(page, huge_page_order(h));
		free_gigantic_page(page, huge_page_order(h));
	} else {
		__free_pages(page, huge_page_order(h));
	}
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 65 38.92% 2 22.22%
Luiz Fernando N. Capitulino 43 25.75% 2 22.22%
Adam Litke 31 18.56% 1 11.11%
Andi Kleen 17 10.18% 1 11.11%
Aneesh Kumar K.V 7 4.19% 1 11.11%
Sasha Levin 3 1.80% 1 11.11%
Kirill A. Shutemov 1 0.60% 1 11.11%
Total 167 100.00% 9 100.00%



struct hstate *size_to_hstate(unsigned long size)
{
	struct hstate *h;

	for_each_hstate(h) {
		if (huge_page_size(h) == size)
			return h;
	}
	return NULL;
}

Contributors
Person Tokens Prop Commits CommitProp
Andi Kleen 37 100.00% 1 100.00%
Total 37 100.00% 1 100.00%

/*
 * Test to determine whether the hugepage is "active/in-use" (i.e. being linked
 * to hstate->hugepage_activelist.)
 *
 * This function can be called for tail pages, but never returns true for them.
 */


bool page_huge_active(struct page *page)
{
	VM_BUG_ON_PAGE(!PageHuge(page), page);
	return PageHead(page) && PagePrivate(&page[1]);
}

Contributors
Person Tokens Prop Commits CommitProp
Naoya Horiguchi 36 100.00% 1 100.00%
Total 36 100.00% 1 100.00%

/* never called for tail page */


static void set_page_huge_active(struct page *page)
{
	VM_BUG_ON_PAGE(!PageHeadHuge(page), page);
	SetPagePrivate(&page[1]);
}

Contributors
Person Tokens Prop Commits CommitProp
Naoya Horiguchi 31 100.00% 1 100.00%
Total 31 100.00% 1 100.00%



static void clear_page_huge_active(struct page *page)
{
	VM_BUG_ON_PAGE(!PageHeadHuge(page), page);
	ClearPagePrivate(&page[1]);
}

Contributors
Person Tokens Prop Commits CommitProp
Naoya Horiguchi 31 100.00% 1 100.00%
Total 31 100.00% 1 100.00%



void free_huge_page(struct page *page)
{
	/*
         * Can't pass hstate in here because it is called from the
         * compound page destructor.
         */
	struct hstate *h = page_hstate(page);
	int nid = page_to_nid(page);
	struct hugepage_subpool *spool =
		(struct hugepage_subpool *)page_private(page);
	bool restore_reserve;

	set_page_private(page, 0);
	page->mapping = NULL;
	VM_BUG_ON_PAGE(page_count(page), page);
	VM_BUG_ON_PAGE(page_mapcount(page), page);
	restore_reserve = PagePrivate(page);
	ClearPagePrivate(page);

	/*
         * A return code of zero implies that the subpool will be under its
         * minimum size if the reservation is not restored after page is free.
         * Therefore, force restore_reserve operation.
         */
	if (hugepage_subpool_put_pages(spool, 1) == 0)
		restore_reserve = true;

	spin_lock(&hugetlb_lock);
	clear_page_huge_active(page);
	hugetlb_cgroup_uncharge_page(hstate_index(h),
				     pages_per_huge_page(h), page);
	if (restore_reserve)
		h->resv_huge_pages++;

	if (h->surplus_huge_pages_node[nid]) {
		/* remove the page from active list */
		list_del(&page->lru);
		update_and_free_page(h, page);
		h->surplus_huge_pages--;
		h->surplus_huge_pages_node[nid]--;
	} else {
		arch_clear_hugepage_flags(page);
		enqueue_huge_page(h, page);
	}
	spin_unlock(&hugetlb_lock);
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 50 24.51% 1 5.88%
Adam Litke 35 17.16% 3 17.65%
Aneesh Kumar K.V 24 11.76% 2 11.76%
JoonSoo Kim 24 11.76% 2 11.76%
Mike Kravetz 22 10.78% 2 11.76%
Andi Kleen 21 10.29% 2 11.76%
Naoya Horiguchi 12 5.88% 2 11.76%
Mel Gorman 6 2.94% 1 5.88%
Will Deacon 5 2.45% 1 5.88%
David Gibson 5 2.45% 1 5.88%
Total 204 100.00% 17 100.00%



static void prep_new_huge_page(struct hstate *h, struct page *page, int nid)
{
	INIT_LIST_HEAD(&page->lru);
	set_compound_page_dtor(page, HUGETLB_PAGE_DTOR);
	spin_lock(&hugetlb_lock);
	set_hugetlb_cgroup(page, NULL);
	h->nr_huge_pages++;
	h->nr_huge_pages_node[nid]++;
	spin_unlock(&hugetlb_lock);
	put_page(page); /* free it into the hugepage allocator */
}

Contributors
Person Tokens Prop Commits CommitProp
Fengguang Wu 27 37.50% 1 10.00%
Adam Litke 15 20.83% 1 10.00%
Aneesh Kumar K.V 15 20.83% 2 20.00%
Andi Kleen 9 12.50% 1 10.00%
Mel Gorman 2 2.78% 1 10.00%
Andy Whitcroft 1 1.39% 1 10.00%
Adrian Bunk 1 1.39% 1 10.00%
Kirill A. Shutemov 1 1.39% 1 10.00%
Nishanth Aravamudan 1 1.39% 1 10.00%
Total 72 100.00% 10 100.00%



static void prep_compound_gigantic_page(struct page *page, unsigned int order)
{
	int i;
	int nr_pages = 1 << order;
	struct page *p = page + 1;

	/* we rely on prep_new_huge_page to set the destructor */
	set_compound_order(page, order);
	__ClearPageReserved(page);
	__SetPageHead(page);
	for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) {
		/*
                 * For gigantic hugepages allocated through bootmem at
                 * boot, it's safer to be consistent with the not-gigantic
                 * hugepages and clear the PG_reserved bit from all tail pages
                 * too.  Otherwse drivers using get_user_pages() to access tail
                 * pages may get the reference counting wrong if they see
                 * PG_reserved set on a tail page (despite the head page not
                 * having PG_reserved set).  Enforcing this consistency between
                 * head and tail pages allows drivers to optimize away a check
                 * on the head page when they need know if put_page() is needed
                 * after get_user_pages().
                 */
		__ClearPageReserved(p);
		set_page_count(p, 0);
		set_compound_head(p, page);
	}
	atomic_set(compound_mapcount_ptr(page), -1);
}

Contributors
Person Tokens Prop Commits CommitProp
Fengguang Wu 52 47.71% 1 11.11%
Andi Kleen 19 17.43% 1 11.11%
Mike Kravetz 11 10.09% 1 11.11%
Andrea Arcangeli 10 9.17% 1 11.11%
Youquan Song 7 6.42% 1 11.11%
Kirill A. Shutemov 6 5.50% 3 33.33%
David Rientjes 4 3.67% 1 11.11%
Total 109 100.00% 9 100.00%

/*
 * PageHuge() only returns true for hugetlbfs pages, but not for normal or
 * transparent huge pages.  See the PageTransHuge() documentation for more
 * details.
 */


int PageHuge(struct page *page)
{
	if (!PageCompound(page))
		return 0;

	page = compound_head(page);
	return page[1].compound_dtor == HUGETLB_PAGE_DTOR;
}
Contributors
Person Tokens Prop Commits CommitProp
Fengguang Wu 26 68.42% 1 25.00%
Kirill A. Shutemov 6 15.79% 1 25.00%
Andi Kleen 5 13.16% 1 25.00%
Andrew Morton 1 2.63% 1 25.00%
Total 38 100.00% 4 100.00%


EXPORT_SYMBOL_GPL(PageHuge);

/*
 * PageHeadHuge() only returns true for hugetlbfs head page, but not for
 * normal or transparent huge pages.
 */


int PageHeadHuge(struct page *page_head)
{
	if (!PageHead(page_head))
		return 0;

	return get_compound_page_dtor(page_head) == free_huge_page;
}

Contributors
Person Tokens Prop Commits CommitProp
Andrea Arcangeli 28 96.55% 1 50.00%
Andrew Morton 1 3.45% 1 50.00%
Total 29 100.00% 2 100.00%



pgoff_t __basepage_index(struct page *page)
{
	struct page *page_head = compound_head(page);
	pgoff_t index = page_index(page_head);
	unsigned long compound_idx;

	if (!PageHuge(page_head))
		return page_index(page);

	if (compound_order(page_head) >= MAX_ORDER)
		compound_idx = page_to_pfn(page) - page_to_pfn(page_head);
	else
		compound_idx = page - page_head;

	return (index << compound_order(page_head)) + compound_idx;
}

Contributors
Person Tokens Prop Commits CommitProp
Zhang Yi 86 100.00% 1 100.00%
Total 86 100.00% 1 100.00%



static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid)
{
	struct page *page;

	page = __alloc_pages_node(nid,
		htlb_alloc_mask(h)|__GFP_COMP|__GFP_THISNODE|
						__GFP_RETRY_MAYFAIL|__GFP_NOWARN,
		huge_page_order(h));
	if (page) {
		prep_new_huge_page(h, page, nid);
	}

	return page;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 29 45.31% 1 7.14%
Andi Kleen 12 18.75% 2 14.29%
Adam Litke 9 14.06% 3 21.43%
David Gibson 3 4.69% 1 7.14%
Naoya Horiguchi 3 4.69% 1 7.14%
Christoph Lameter 2 3.12% 1 7.14%
Andrew Morton 2 3.12% 1 7.14%
Ken Chen 1 1.56% 1 7.14%
Vlastimil Babka 1 1.56% 1 7.14%
Mel Gorman 1 1.56% 1 7.14%
Michal Hocko 1 1.56% 1 7.14%
Total 64 100.00% 14 100.00%



static int alloc_fresh_huge_page(struct hstate *h, nodemask_t *nodes_allowed)
{
	struct page *page;
	int nr_nodes, node;
	int ret = 0;

	for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) {
		page = alloc_fresh_huge_page_node(h, node);
		if (page) {
			ret = 1;
			break;
		}
	}

	if (ret)
		count_vm_event(HTLB_BUDDY_PGALLOC);
	else
		count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);

	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 29 36.25% 1 11.11%
JoonSoo Kim 11 13.75% 1 11.11%
Lee Schermerhorn 10 12.50% 2 22.22%
Kenneth W. Chen 8 10.00% 1 11.11%
David Gibson 6 7.50% 1 11.11%
Ken Chen 6 7.50% 1 11.11%
Andi Kleen 6 7.50% 1 11.11%
Andrew Morton 4 5.00% 1 11.11%
Total 80 100.00% 9 100.00%

/*
 * Free huge page from pool from next node to free.
 * Attempt to keep persistent huge pages more or less
 * balanced over allowed nodes.
 * Called with hugetlb_lock locked.
 */


static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed,
							 bool acct_surplus)
{
	int nr_nodes, node;
	int ret = 0;

	for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) {
		/*
                 * If we're returning unused surplus pages, only examine
                 * nodes with surplus pages.
                 */
		if ((!acct_surplus || h->surplus_huge_pages_node[node]) &&
		    !list_empty(&h->hugepage_freelists[node])) {
			struct page *page =
				list_entry(h->hugepage_freelists[node].next,
					  struct page, lru);
			list_del(&page->lru);
			h->free_huge_pages--;
			h->free_huge_pages_node[node]--;
			if (acct_surplus) {
				h->surplus_huge_pages--;
				h->surplus_huge_pages_node[node]--;
			}
			update_and_free_page(h, page);
			ret = 1;
			break;
		}
	}

	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
Lee Schermerhorn 131 89.73% 4 80.00%
JoonSoo Kim 15 10.27% 1 20.00%
Total 146 100.00% 5 100.00%

/*
 * Dissolve a given free hugepage into free buddy pages. This function does
 * nothing for in-use (including surplus) hugepages. Returns -EBUSY if the
 * number of free hugepages would be reduced below the number of reserved
 * hugepages.
 */


int dissolve_free_huge_page(struct page *page)
{
	int rc = 0;

	spin_lock(&hugetlb_lock);
	if (PageHuge(page) && !page_count(page)) {
		struct page *head = compound_head(page);
		struct hstate *h = page_hstate(head);
		int nid = page_to_nid(head);
		if (h->free_huge_pages - h->resv_huge_pages == 0) {
			rc = -EBUSY;
			goto out;
		}
		/*
                 * Move PageHWPoison flag from head page to the raw error page,
                 * which makes any subpages rather than the error page reusable.
                 */
		if (PageHWPoison(head) && page != head) {
			SetPageHWPoison(page);
			ClearPageHWPoison(head);
		}
		list_del(&head->lru);
		h->free_huge_pages--;
		h->free_huge_pages_node[nid]--;
		h->max_huge_pages--;
		update_and_free_page(h, head);
	}
out:
	spin_unlock(&hugetlb_lock);
	return rc;
}

Contributors
Person Tokens Prop Commits CommitProp
Naoya Horiguchi 78 50.65% 1 20.00%
Gerald Schaefer 47 30.52% 2 40.00%
Anshuman Khandual 24 15.58% 1 20.00%
zhong jiang 5 3.25% 1 20.00%
Total 154 100.00% 5 100.00%

/*
 * Dissolve free hugepages in a given pfn range. Used by memory hotplug to
 * make specified memory blocks removable from the system.
 * Note that this will dissolve a free gigantic hugepage completely, if any
 * part of it lies within the given range.
 * Also note that if dissolve_free_huge_page() returns with an error, all
 * free hugepages that were dissolved before that error are lost.
 */


int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn)
{
	unsigned long pfn;
	struct page *page;
	int rc = 0;

	if (!hugepages_supported())
		return rc;

	for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << minimum_order) {
		page = pfn_to_page(pfn);
		if (PageHuge(page) && !page_count(page)) {
			rc = dissolve_free_huge_page(page);
			if (rc)
				break;
		}
	}

	return rc;
}

Contributors
Person Tokens Prop Commits CommitProp
Gerald Schaefer 50 54.95% 2 40.00%
Naoya Horiguchi 35 38.46% 2 40.00%
Li Zhong 6 6.59% 1 20.00%
Total 91 100.00% 5 100.00%



static struct page *__hugetlb_alloc_buddy_huge_page(struct hstate *h,
		gfp_t gfp_mask, int nid, nodemask_t *nmask)
{
	int order = huge_page_order(h);

	gfp_mask |= __GFP_COMP|__GFP_RETRY_MAYFAIL|__GFP_NOWARN;
	if (nid == NUMA_NO_NODE)
		nid = numa_mem_id();
	return __alloc_pages_nodemask(gfp_mask, order, nid, nmask);
}

Contributors
Person Tokens Prop Commits CommitProp
Dave Hansen 45 72.58% 1 25.00%
Michal Hocko 15 24.19% 2 50.00%
Vlastimil Babka 2 3.23% 1 25.00%
Total 62 100.00% 4 100.00%



static struct page *__alloc_buddy_huge_page(struct hstate *h, gfp_t gfp_mask,
		int nid, nodemask_t *nmask)
{
	struct page *page;
	unsigned int r_nid;

	if (hstate_is_gigantic(h))
		return NULL;

	/*
         * Assume we will successfully allocate the surplus page to
         * prevent racing processes from causing the surplus to exceed
         * overcommit
         *
         * This however introduces a different race, where a process B
         * tries to grow the static hugepage pool while alloc_pages() is
         * called by process A. B will only examine the per-node
         * counters in determining if surplus huge pages can be
         * converted to normal huge pages in adjust_pool_surplus(). A
         * won't be able to increment the per-node counter, until the
         * lock is dropped by B, but B doesn't drop hugetlb_lock until
         * no more huge pages can be converted from surplus to normal
         * state (and doesn't try to convert again). Thus, we have a
         * case where a surplus huge page exists, the pool is grown, and
         * the surplus huge page still exists after, even though it
         * should just have been converted to a normal huge page. This
         * does not leak memory, though, as the hugepage will be freed
         * once it is out of use. It also does not allow the counters to
         * go out of whack in adjust_pool_surplus() as we don't modify
         * the node values until we've gotten the hugepage and only the
         * per-node value is checked there.
         */
	spin_lock(&hugetlb_lock);
	if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) {
		spin_unlock(&hugetlb_lock);
		return NULL;
	} else {
		h->nr_huge_pages++;
		h->surplus_huge_pages++;
	}
	spin_unlock(&hugetlb_lock);

	page = __hugetlb_alloc_buddy_huge_page(h, gfp_mask, nid, nmask);

	spin_lock(&hugetlb_lock);
	if (page) {
		INIT_LIST_HEAD(&page->lru);
		r_nid = page_to_nid(page);
		set_compound_page_dtor(page, HUGETLB_PAGE_DTOR);
		set_hugetlb_cgroup(page, NULL);
		/*
                 * We incremented the global counters already
                 */
		h->nr_huge_pages_node[r_nid]++;
		h->surplus_huge_pages_node[r_nid]++;
		__count_vm_event(HTLB_BUDDY_PGALLOC);
	} else {
		h->nr_huge_pages--;
		h->surplus_huge_pages--;
		__count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
	}
	spin_unlock(&hugetlb_lock);

	return page;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 94 48.96% 1 6.67%
Andi Kleen 27 14.06% 2 13.33%
Andrew Morton 20 10.42% 1 6.67%
Aneesh Kumar K.V 15 7.81% 2 13.33%
Naoya Horiguchi 11 5.73% 2 13.33%
Michal Hocko 9 4.69% 1 6.67%
Dave Hansen 4 2.08% 1 6.67%
Adam Litke 4 2.08% 1 6.67%
Luiz Fernando N. Capitulino 3 1.56% 1 6.67%
Christoph Lameter 2 1.04% 1 6.67%
Kenneth W. Chen 2 1.04% 1 6.67%
Kirill A. Shutemov 1 0.52% 1 6.67%
Total 192 100.00% 15 100.00%

/*
 * Use the VMA's mpolicy to allocate a huge page from the buddy.
 */

static

struct page *__alloc_buddy_huge_page_with_mpol(struct hstate *h,
		struct vm_area_struct *vma, unsigned long addr)
{
	struct page *page;
	struct mempolicy *mpol;
	gfp_t gfp_mask = htlb_alloc_mask(h);
	int nid;
	nodemask_t *nodemask;

	nid = huge_node(vma, addr, gfp_mask, &mpol, &nodemask);
	page = __alloc_buddy_huge_page(h, gfp_mask, nid, nodemask);
	mpol_cond_put(mpol);

	return page;
}

Contributors
Person Tokens Prop Commits CommitProp
Michal Hocko 55 64.71% 1 33.33%
Dave Hansen 30 35.29% 2 66.67%
Total 85 100.00% 3 100.00%

/*
 * This allocation function is useful in the context where vma is irrelevant.
 * E.g. soft-offlining uses this function because it only cares physical
 * address of error page.
 */


struct page *alloc_huge_page_node(struct hstate *h, int nid)
{
	gfp_t gfp_mask = htlb_alloc_mask(h);
	struct page *page = NULL;

	if (nid != NUMA_NO_NODE)
		gfp_mask |= __GFP_THISNODE;

	spin_lock(&hugetlb_lock);
	if (h->free_huge_pages - h->resv_huge_pages > 0)
		page = dequeue_huge_page_nodemask(h, gfp_mask, nid, NULL);
	spin_unlock(&hugetlb_lock);

	if (!page)
		page = __alloc_buddy_huge_page(h, gfp_mask, nid, NULL);

	return page;
}


Contributors
Person Tokens Prop Commits CommitProp
Naoya Horiguchi 56 57.14% 1 25.00%
Michal Hocko 28 28.57% 2 50.00%
JoonSoo Kim 14 14.29% 1 25.00%
Total 98 100.00% 4 100.00%



struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid,
		nodemask_t *nmask)
{
	gfp_t gfp_mask = htlb_alloc_mask(h);

	spin_lock(&hugetlb_lock);
	if (h->free_huge_pages - h->resv_huge_pages > 0) {
		struct page *page;

		page = dequeue_huge_page_nodemask(h, gfp_mask, preferred_nid, nmask);
		if (page) {
			spin_unlock(&hugetlb_lock);
			return page;
		}
	}
	spin_unlock(&hugetlb_lock);

	/* No reservations, try to overcommit */

	return __alloc_buddy_huge_page(h, gfp_mask, preferred_nid, nmask);
}

Contributors
Person Tokens Prop Commits CommitProp
Michal Hocko 99 100.00% 3 100.00%
Total 99 100.00% 3 100.00%

/*
 * Increase the hugetlb pool such that it can accommodate a reservation
 * of size 'delta'.
 */


static int gather_surplus_pages(struct hstate *h, int delta)
{
	struct list_head surplus_list;
	struct page *page, *tmp;
	int ret, i;
	int needed, allocated;
	bool alloc_ok = true;

	needed = (h->resv_huge_pages + delta) - h->free_huge_pages;
	if (needed <= 0) {
		h->resv_huge_pages += delta;
		return 0;
	}

	allocated = 0;
	INIT_LIST_HEAD(&surplus_list);

	ret = -ENOMEM;
retry:
	spin_unlock(&hugetlb_lock);
	for (i = 0; i < needed; i++) {
		page = __alloc_buddy_huge_page(h, htlb_alloc_mask(h),
				NUMA_NO_NODE, NULL);
		if (!page) {
			alloc_ok = false;
			break;
		}
		list_add(&page->lru, &surplus_list);
		cond_resched();
	}
	allocated += i;

	/*
         * After retaking hugetlb_lock, we need to recalculate 'needed'
         * because either resv_huge_pages or free_huge_pages may have changed.
         */
	spin_lock(&hugetlb_lock);
	needed = (h->resv_huge_pages + delta) -
			(h->free_huge_pages + allocated);
	if (needed > 0) {
		if (alloc_ok)
			goto retry;
		/*
                 * We were not able to allocate enough pages to
                 * satisfy the entire reservation so we free what
                 * we've allocated so far.
                 */
		goto free;
	}
	/*
         * The surplus_list now contains _at_least_ the number of extra pages
         * needed to accommodate the reservation.  Add the appropriate number
         * of pages to the hugetlb pool and free the extras back to the buddy
         * allocator.  Commit the entire reservation here to prevent another
         * process from stealing the pages as they are added to the pool but
         * before they are reserved.
         */
	needed += allocated;
	h->resv_huge_pages += delta;
	ret = 0;

	/* Free the needed pages to the hugetlb pool */
	list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
		if ((--needed) < 0)
			break;
		/*
                 * This page is now managed by the hugetlb allocator and has
                 * no users -- drop the buddy allocator's reference.
                 */
		put_page_testzero(page);
		VM_BUG_ON_PAGE(page_count(page), page);
		enqueue_huge_page(h, page);
	}
free:
	spin_unlock(&hugetlb_lock);

	/* Free unnecessary surplus pages to the buddy allocator */
	list_for_each_entry_safe(page, tmp, &surplus_list, lru)
		put_page(page);
	spin_lock(&hugetlb_lock);

	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 153 52.04% 1 5.88%
Hillf Danton 31 10.54% 2 11.76%
Andrew Morton 25 8.50% 1 5.88%
Andi Kleen 21 7.14% 1 5.88%
Adam Litke 19 6.46% 2 11.76%
Naoya Horiguchi 15 5.10% 2 11.76%
Nishanth Aravamudan 9 3.06% 2 11.76%
Michal Hocko 8 2.72% 1 5.88%
Mel Gorman 5 1.70% 1 5.88%
David Rientjes 3 1.02% 1 5.88%
Sasha Levin 3 1.02% 1 5.88%
Lucas De Marchi 1 0.34% 1 5.88%
Kenneth W. Chen 1 0.34% 1 5.88%
Total 294 100.00% 17 100.00%

/*
 * This routine has two main purposes:
 * 1) Decrement the reservation count (resv_huge_pages) by the value passed
 *    in unused_resv_pages.  This corresponds to the prior adjustments made
 *    to the associated reservation map.
 * 2) Free any unused surplus pages that may have been allocated to satisfy
 *    the reservation.  As many as unused_resv_pages may be freed.
 *
 * Called with hugetlb_lock held.  However, the lock could be dropped (and
 * reacquired) during calls to cond_resched_lock.  Whenever dropping the lock,
 * we must make sure nobody else can claim pages we are in the process of
 * freeing.  Do this by ensuring resv_huge_page always is greater than the
 * number of huge pages we plan to free when dropping the lock.
 */


static void return_unused_surplus_pages(struct hstate *h,
					unsigned long unused_resv_pages)
{
	unsigned long nr_pages;

	/* Cannot return gigantic pages currently */
	if (hstate_is_gigantic(h))
		goto out;

	/*
         * Part (or even all) of the reservation could have been backed
         * by pre-allocated pages. Only free surplus pages.
         */
	nr_pages = min(unused_resv_pages, h->surplus_huge_pages);

	/*
         * We want to release as many surplus pages as possible, spread
         * evenly across all nodes with memory. Iterate across these nodes
         * until we can no longer free unreserved surplus pages. This occurs
         * when the nodes with surplus pages have no free pages.
         * free_pool_huge_page() will balance the the freed pages across the
         * on-line nodes with memory and will handle the hstate accounting.
         *
         * Note that we decrement resv_huge_pages as we free the pages.  If
         * we drop the lock, resv_huge_pages will still be sufficiently large
         * to cover subsequent pages we may free.
         */
	while (nr_pages--) {
		h->resv_huge_pages--;
		unused_resv_pages--;
		if (!free_pool_huge_page(h, &node_states[N_MEMORY], 1))
			goto out;
		cond_resched_lock(&hugetlb_lock);
	}

out:
	/* Fully uncommit the reservation */
	h->resv_huge_pages -= unused_resv_pages;
}


Contributors
Person Tokens Prop Commits CommitProp
Mike Kravetz 25 27.17% 1 7.14%
Andy Whitcroft 25 27.17% 1 7.14%
Andi Kleen 14 15.22% 2 14.29%
Lee Schermerhorn 9 9.78% 3 21.43%
Masayoshi Mizuma 6 6.52% 1 7.14%
Andrew Morton 5 5.43% 1 7.14%
Luiz Fernando N. Capitulino 3 3.26% 1 7.14%
Kenneth W. Chen 2 2.17% 1 7.14%
David Gibson 1 1.09% 1 7.14%
Adam Litke 1 1.09% 1 7.14%
Lai Jiangshan 1 1.09% 1 7.14%
Total 92 100.00% 14 100.00%

/*
 * vma_needs_reservation, vma_commit_reservation and vma_end_reservation
 * are used by the huge page allocation routines to manage reservations.
 *
 * vma_needs_reservation is called to determine if the huge page at addr
 * within the vma has an associated reservation.  If a reservation is
 * needed, the value 1 is returned.  The caller is then responsible for
 * managing the global reservation and subpool usage counts.  After
 * the huge page has been allocated, vma_commit_reservation is called
 * to add the page to the reservation map.  If the page allocation fails,
 * the reservation must be ended instead of committed.  vma_end_reservation
 * is called in such cases.
 *
 * In the normal case, vma_commit_reservation returns the same value
 * as the preceding vma_needs_reservation call.  The only time this
 * is not the case is if a reserve map was changed between calls.  It
 * is the responsibility of the caller to notice the difference and
 * take appropriate action.
 *
 * vma_add_reservation is used in error paths where a reservation must
 * be restored when a newly allocated huge page must be freed.  It is
 * to be called after calling vma_needs_reservation to determine if a
 * reservation exists.
 */

enum vma_resv_mode {
	
VMA_NEEDS_RESV,
	
VMA_COMMIT_RESV,
	
VMA_END_RESV,
	
VMA_ADD_RESV,
};


static long __vma_reservation_common(struct hstate *h,
				struct vm_area_struct *vma, unsigned long addr,
				enum vma_resv_mode mode)
{
	struct resv_map *resv;
	pgoff_t idx;
	long ret;

	resv = vma_resv_map(vma);
	if (!resv)
		return 1;

	idx = vma_hugecache_offset(h, vma, addr);
	switch (mode) {
	case VMA_NEEDS_RESV:
		ret = region_chg(resv, idx, idx + 1);
		break;
	case VMA_COMMIT_RESV:
		ret = region_add(resv, idx, idx + 1);
		break;
	case VMA_END_RESV:
		region_abort(resv, idx, idx + 1);
		ret = 0;
		break;
	case VMA_ADD_RESV:
		if (vma->vm_flags & VM_MAYSHARE)
			ret = region_add(resv, idx, idx + 1);
		else {
			region_abort(resv, idx, idx + 1);
			ret = region_del(resv, idx, idx + 1);
		}
		break;
	default:
		BUG();
	}

	if (vma->vm_flags & VM_MAYSHARE)
		return ret;
	else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) && ret >= 0) {
		/*
                 * In most cases, reserves always exist for private mappings.
                 * However, a file associated with mapping could have been
                 * hole punched or truncated after reserves were consumed.
                 * As subsequent fault on such a range will not use reserves.
                 * Subtle - The reserve map for private mappings has the
                 * opposite meaning than that of shared mappings.  If NO
                 * entry is in the reserve map, it means a reservation exists.
                 * If an entry exists in the reserve map, it means the
                 * reservation has already been consumed.  As a result, the
                 * return value of this routine is the opposite of the
                 * value returned from reserve map manipulation routines above.
                 */
		if (ret)
			return 0;
		else
			return 1;
	}
	else
		return ret < 0 ? ret : 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Kravetz 141 62.67% 5 38.46%
Andy Whitcroft 51 22.67% 2 15.38%
JoonSoo Kim 24 10.67% 3 23.08%
Andi Kleen 7 3.11% 1 7.69%
Roel Kluin 1 0.44% 1 7.69%
Johannes Weiner 1 0.44% 1 7.69%
Total 225 100.00% 13 100.00%



static long vma_needs_reservation(struct hstate *h,
			struct vm_area_struct *vma, unsigned long addr)
{
	return __vma_reservation_common(h, vma, addr, VMA_NEEDS_RESV);
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 17 53.12% 2 40.00%
Mike Kravetz 8 25.00% 2 40.00%
Andi Kleen 7 21.88% 1 20.00%
Total 32 100.00% 5 100.00%



static long vma_commit_reservation(struct hstate *h,
			struct vm_area_struct *vma, unsigned long addr)
{
	return __vma_reservation_common(h, vma, addr, VMA_COMMIT_RESV);
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Kravetz 27 84.38% 2 66.67%
Andy Whitcroft 5 15.62% 1 33.33%
Total 32 100.00% 3 100.00%



static void vma_end_reservation(struct hstate *h,
			struct vm_area_struct *vma, unsigned long addr)
{
	(void)__vma_reservation_common(h, vma, addr, VMA_END_RESV);
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Kravetz 34 100.00% 2 100.00%
Total 34 100.00% 2 100.00%



static long vma_add_reservation(struct hstate *h,
			struct vm_area_struct *vma, unsigned long addr)
{
	return __vma_reservation_common(h, vma, addr, VMA_ADD_RESV);
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Kravetz 32 100.00% 1 100.00%
Total 32 100.00% 1 100.00%

/*
 * This routine is called to restore a reservation on error paths.  In the
 * specific error paths, a huge page was allocated (via alloc_huge_page)
 * and is about to be freed.  If a reservation for the page existed,
 * alloc_huge_page would have consumed the reservation and set PagePrivate
 * in the newly allocated page.  When the page is freed via free_huge_page,
 * the global reservation count will be incremented if PagePrivate is set.
 * However, free_huge_page can not adjust the reserve map.  Adjust the
 * reserve map here to be consistent with global reserve count adjustments
 * to be made by free_huge_page.
 */


static void restore_reserve_on_error(struct hstate *h,
			struct vm_area_struct *vma, unsigned long address,
			struct page *page)
{
	if (unlikely(PagePrivate(page))) {
		long rc = vma_needs_reservation(h, vma, address);

		if (unlikely(rc < 0)) {
			/*
                         * Rare out of memory condition in reserve map
                         * manipulation.  Clear PagePrivate so that
                         * global reserve count will not be incremented
                         * by free_huge_page.  This will make it appear
                         * as though the reservation for this page was
                         * consumed.  This may prevent the task from
                         * faulting in the page at a later time.  This
                         * is better than inconsistent global huge page
                         * accounting of reserve counts.
                         */
			ClearPagePrivate(page);
		} else if (rc) {
			rc = vma_add_reservation(h, vma, address);
			if (unlikely(rc < 0))
				/*
                                 * See above comment about rare out of
                                 * memory condition.
                                 */
				ClearPagePrivate(page);
		} else
			vma_end_reservation(h, vma, address);
	}
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Kravetz 109 100.00% 1 100.00%
Total 109 100.00% 1 100.00%



struct page *alloc_huge_page(struct vm_area_struct *vma,
				    unsigned long addr, int avoid_reserve)
{
	struct hugepage_subpool *spool = subpool_vma(vma);
	struct hstate *h = hstate_vma(vma);
	struct page *page;
	long map_chg, map_commit;
	long gbl_chg;
	int ret, idx;
	struct hugetlb_cgroup *h_cg;

	idx = hstate_index(h);
	/*
         * Examine the region/reserve map to determine if the process
         * has a reservation for the page to be allocated.  A return
         * code of zero indicates a reservation exists (no change).
         */
	map_chg = gbl_chg = vma_needs_reservation(h, vma, addr);
	if (map_chg < 0)
		return ERR_PTR(-ENOMEM);

	/*
         * Processes that did not create the mapping will have no
         * reserves as indicated by the region/reserve map. Check
         * that the allocation will not exceed the subpool limit.
         * Allocations for MAP_NORESERVE mappings also need to be
         * checked against any subpool limit.
         */
	if (map_chg || avoid_reserve) {
		gbl_chg = hugepage_subpool_get_pages(spool, 1);
		if (gbl_chg < 0) {
			vma_end_reservation(h, vma, addr);
			return ERR_PTR(-ENOSPC);
		}

		/*
                 * Even though there was no reservation in the region/reserve
                 * map, there could be reservations associated with the
                 * subpool that can be used.  This would be indicated if the
                 * return value of hugepage_subpool_get_pages() is zero.
                 * However, if avoid_reserve is specified we still avoid even
                 * the subpool reservations.
                 */
		if (avoid_reserve)
			gbl_chg = 1;
	}

	ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg);
	if (ret)
		goto out_subpool_put;

	spin_lock(&hugetlb_lock);
	/*
         * glb_chg is passed to indicate whether or not a page must be taken
         * from the global free pool (global change).  gbl_chg == 0 indicates
         * a reservation exists for the allocation.
         */
	page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve, gbl_chg);
	if (!page) {
		spin_unlock(&hugetlb_lock);
		page = __alloc_buddy_huge_page_with_mpol(h, vma, addr);
		if (!page)
			goto out_uncharge_cgroup;
		if (!avoid_reserve && vma_has_reserves(vma, gbl_chg)) {
			SetPagePrivate(page);
			h->resv_huge_pages--;
		}
		spin_lock(&hugetlb_lock);
		list_move(&page->lru, &h->hugepage_activelist);
		/* Fall through */
	}
	hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page);
	spin_unlock(&hugetlb_lock);

	set_page_private(page, (unsigned long)spool);

	map_commit = vma_commit_reservation(h, vma, addr);
	if (unlikely(map_chg > map_commit)) {
		/*
                 * The page was added to the reservation map between
                 * vma_needs_reservation and vma_commit_reservation.
                 * This indicates a race with hugetlb_reserve_pages.
                 * Adjust for the subpool count incremented above AND
                 * in hugetlb_reserve_pages for the same page.  Also,
                 * the reservation count added in hugetlb_reserve_pages
                 * no longer applies.
                 */
		long rsv_adjust;

		rsv_adjust = hugepage_subpool_put_pages(spool, 1);
		hugetlb_acct_memory(h, -rsv_adjust);
	}
	return page;

out_uncharge_cgroup:
	hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h), h_cg);
out_subpool_put:
	if (map_chg || avoid_reserve)
		hugepage_subpool_put_pages(spool, 1);
	vma_end_reservation(h, vma, addr);
	return ERR_PTR(-ENOSPC);
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Kravetz 89 22.88% 5 20.83%
Andy Whitcroft 82 21.08% 2 8.33%
Aneesh Kumar K.V 75 19.28% 4 16.67%
Jianyu Zhan 41 10.54% 1 4.17%
Naoya Horiguchi 24 6.17% 1 4.17%
Mel Gorman 23 5.91% 2 8.33%
JoonSoo Kim 20 5.14% 3 12.50%
Andi Kleen 15 3.86% 1 4.17%
David Gibson 14 3.60% 2 8.33%
Dave Hansen 4 1.03% 1 4.17%
Hugh Dickins 1 0.26% 1 4.17%
Roel Kluin 1 0.26% 1 4.17%
Total 389 100.00% 24 100.00%

/*
 * alloc_huge_page()'s wrapper which simply returns the page if allocation
 * succeeds, otherwise NULL. This function is called from new_vma_page(),
 * where no ERR_VALUE is expected to be returned.
 */


struct page *alloc_huge_page_noerr(struct vm_area_struct *vma,
				unsigned long addr, int avoid_reserve)
{
	struct page *page = alloc_huge_page(vma, addr, avoid_reserve);
	if (IS_ERR(page))
		page = NULL;
	return page;
}

Contributors
Person Tokens Prop Commits CommitProp
Naoya Horiguchi 47 100.00% 1 100.00%
Total 47 100.00% 1 100.00%



int __weak alloc_bootmem_huge_page(struct hstate *h)
{
	struct huge_bootmem_page *m;
	int nr_nodes, node;

	for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) {
		void *addr;

		addr = memblock_virt_alloc_try_nid_nopanic(
				huge_page_size(h), huge_page_size(h),
				0, BOOTMEM_ALLOC_ACCESSIBLE, node);
		if (addr) {
			/*
                         * Use the beginning of the huge page to store the
                         * huge_bootmem_page struct (until gather_bootmem
                         * puts them into the mem_map).
                         */
			m = addr;
			goto found;
		}
	}
	return 0;

found:
	BUG_ON(!IS_ALIGNED(virt_to_phys(m), huge_page_size(h)));
	/* Put them into a private list first because mem_map is not up yet */
	list_add(&m->list, &huge_boot_pages);
	m->hstate = h;
	return 1;
}

Contributors
Person Tokens Prop Commits CommitProp
Andi Kleen 93 80.87% 1 20.00%
JoonSoo Kim 11 9.57% 1 20.00%
Luiz Fernando N. Capitulino 5 4.35% 1 20.00%
Grygorii Strashko 5 4.35% 1 20.00%
Cyrill V. Gorcunov 1 0.87% 1 20.00%
Total 115 100.00% 5 100.00%



static void __init prep_compound_huge_page(struct page *page,
		unsigned int order)
{
	if (unlikely(order > (MAX_ORDER - 1)))
		prep_compound_gigantic_page(page, order);
	else
		prep_compound_page(page, order);
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 42 95.45% 1 33.33%
Kirill A. Shutemov 1 2.27% 1 33.33%
David Rientjes 1 2.27% 1 33.33%
Total 44 100.00% 3 100.00%

/* Put bootmem huge pages into the standard lists after mem_map is up */


static void __init gather_bootmem_prealloc(void)
{
	struct huge_bootmem_page *m;

	list_for_each_entry(m, &huge_boot_pages, list) {
		struct hstate *h = m->hstate;
		struct page *page;

#ifdef CONFIG_HIGHMEM
		page = pfn_to_page(m->phys >> PAGE_SHIFT);
		memblock_free_late(__pa(m),
				   sizeof(struct huge_bootmem_page));
#else
		page = virt_to_page(m);
#endif
		WARN_ON(page_count(page) != 1);
		prep_compound_huge_page(page, h->order);
		WARN_ON(PageReserved(page));
		prep_new_huge_page(h, page, page_to_nid(page));
		/*
                 * If we had gigantic hugepages allocated at boot time, we need
                 * to restore the 'stolen' pages to totalram_pages in order to
                 * fix confusing memory reports from free(1) and another
                 * side-effects, like CommitLimit going negative.
                 */
		if (hstate_is_gigantic(h))
			adjust_managed_page_count(page, 1 << h->order);
	}
}

Contributors
Person Tokens Prop Commits CommitProp
Andi Kleen 63 46.67% 1 12.50%
Becky Bruce 40 29.63% 1 12.50%
Rafael Aquini 11 8.15% 1 12.50%
Andrea Arcangeli 8 5.93% 1 12.50%
Jiang Liu 5 3.70% 1 12.50%
Grygorii Strashko 4 2.96% 1 12.50%
Luiz Fernando N. Capitulino 3 2.22% 1 12.50%
Andy Whitcroft 1 0.74% 1 12.50%
Total 135 100.00% 8 100.00%



static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
{
	unsigned long i;

	for (i = 0; i < h->max_huge_pages; ++i) {
		if (hstate_is_gigantic(h)) {
			if (!alloc_bootmem_huge_page(h))
				break;
		} else if (!alloc_fresh_huge_page(h,
					 &node_states[N_MEMORY]))
			break;
		cond_resched();
	}
	if (i < h->max_huge_pages) {
		char buf[32];

		string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32);
		pr_warn("HugeTLB: allocating %lu of page size %s failed.  Only allocated %lu hugepages.\n",
			h->max_huge_pages, buf, i);
		h->max_huge_pages = i;
	}
}

Contributors
Person Tokens Prop Commits CommitProp
Liam R. Howlett 35 28.93% 1 7.69%
Andi Kleen 30 24.79% 4 30.77%
Andy Whitcroft 28 23.14% 1 7.69%
Matthew Wilcox 10 8.26% 1 7.69%
David Gibson 6 4.96% 1 7.69%
Lee Schermerhorn 5 4.13% 2 15.38%
Luiz Fernando N. Capitulino 3 2.48% 1 7.69%
David Rientjes 3 2.48% 1 7.69%
Lai Jiangshan 1 0.83% 1 7.69%
Total 121 100.00% 13 100.00%



static void __init hugetlb_init_hstates(void)
{
	struct hstate *h;

	for_each_hstate(h) {
		if (minimum_order > huge_page_order(h))
			minimum_order = huge_page_order(h);

		/* oversize hugepages were init'ed in early boot */
		if (!hstate_is_gigantic(h))
			hugetlb_hstate_alloc_pages(h);
	}
	VM_BUG_ON(minimum_order == UINT_MAX);
}

Contributors
Person Tokens Prop Commits CommitProp
Andi Kleen 30 52.63% 2 50.00%
Naoya Horiguchi 23 40.35% 1 25.00%
Luiz Fernando N. Capitulino 4 7.02% 1 25.00%
Total 57 100.00% 4 100.00%



static void __init report_hugepages(void)
{
	struct hstate *h;

	for_each_hstate(h) {
		char buf[32];

		string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32);
		pr_info("HugeTLB registered %s page size, pre-allocated %ld pages\n",
			buf, h->free_huge_pages);
	}
}

Contributors
Person Tokens Prop Commits CommitProp
Andi Kleen 36 67.92% 3 60.00%
Matthew Wilcox 15 28.30% 1 20.00%
David Gibson 2 3.77% 1 20.00%
Total 53 100.00% 5 100.00%

#ifdef CONFIG_HIGHMEM


static void try_to_free_low(struct hstate *h, unsigned long count,
						nodemask_t *nodes_allowed)
{
	int i;

	if (hstate_is_gigantic(h))
		return;

	for_each_node_mask(i, *nodes_allowed) {
		struct page *page, *next;
		struct list_head *freel = &h->hugepage_freelists[i];
		list_for_each_entry_safe(page, next, freel, lru) {
			if (count >= h->nr_huge_pages)
				return;
			if (PageHighMem(page))
				continue;
			list_del(&page->lru);
			update_and_free_page(h, page);
			h->free_huge_pages--;
			h->free_huge_pages_node[page_to_nid(page)]--;
		}
	}
}
Contributors
Person Tokens Prop Commits CommitProp
Nishanth Aravamudan 81 68.07% 1 16.67%
Andi Kleen 22 18.49% 2 33.33%
Lee Schermerhorn 10 8.40% 1 16.67%
Luiz Fernando N. Capitulino 3 2.52% 1 16.67%
Andy Whitcroft 3 2.52% 1 16.67%
Total 119 100.00% 6 100.00%

#else


static inline void try_to_free_low(struct hstate *h, unsigned long count,
						nodemask_t *nodes_allowed)
{
}
Contributors
Person Tokens Prop Commits CommitProp
Nishanth Aravamudan 11 57.89% 1 33.33%
Lee Schermerhorn 4 21.05% 1 33.33%
Andi Kleen 4 21.05% 1 33.33%
Total 19 100.00% 3 100.00%

#endif

/*
 * Increment or decrement surplus_huge_pages.  Keep node-specific counters
 * balanced by operating on them in a round-robin fashion.
 * Returns 1 if an adjustment was made.
 */


static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed,
				int delta)
{
	int nr_nodes, node;

	VM_BUG_ON(delta != -1 && delta != 1);

	if (delta < 0) {
		for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) {
			if (h->surplus_huge_pages_node[node])
				goto found;
		}
	} else {
		for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) {
			if (h->surplus_huge_pages_node[node] <
					h->nr_huge_pages_node[node])
				goto found;
		}
	}
	return 0;

found:
	h->surplus_huge_pages += delta;
	h->surplus_huge_pages_node[node] += delta;
	return 1;
}

Contributors
Person Tokens Prop Commits CommitProp
Fengguang Wu 63 50.81% 1 20.00%
JoonSoo Kim 36 29.03% 1 20.00%
Lee Schermerhorn 25 20.16% 3 60.00%
Total 124 100.00% 5 100.00%


#define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages)


static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count,
						nodemask_t *nodes_allowed)
{
	unsigned long min_count, ret;

	if (hstate_is_gigantic(h) && !gigantic_page_supported())
		return h->max_huge_pages;

	/*
         * Increase the pool size
         * First take pages out of surplus state.  Then make up the
         * remaining difference by allocating fresh huge pages.
         *
         * We might race with __alloc_buddy_huge_page() here and be unable
         * to convert a surplus huge page to a normal huge page. That is
         * not critical, though, it just means the overall size of the
         * pool might be one hugepage larger than it needs to be, but
         * within all the constraints specified by the sysctls.
         */
	spin_lock(&hugetlb_lock);
	while (h->surplus_huge_pages && count > persistent_huge_pages(h)) {
		if (!adjust_pool_surplus(h, nodes_allowed, -1))
			break;
	}

	while (count > persistent_huge_pages(h)) {
		/*
                 * If this allocation races such that we no longer need the
                 * page, free_huge_page will handle it by freeing the page
                 * and reducing the surplus.
                 */
		spin_unlock(&hugetlb_lock);

		/* yield cpu to avoid soft lockup */
		cond_resched();

		if (hstate_is_gigantic(h))
			ret = alloc_fresh_gigantic_page(h, nodes_allowed);
		else
			ret = alloc_fresh_huge_page(h, nodes_allowed);
		spin_lock(&hugetlb_lock);
		if (!ret)
			goto out;

		/* Bail for signals. Probably ctrl-c from user */
		if (signal_pending(current))
			goto out;
	}

	/*
         * Decrease the pool size
         * First return free pages to the buddy allocator (being careful
         * to keep enough around to satisfy reservations).  Then place
         * pages into surplus state as needed so the pool will shrink
         * to the desired size as pages become free.
         *
         * By placing pages into the surplus state independent of the
         * overcommit value, we are allowing the surplus pool size to
         * exceed overcommit. There are few sane options here. Since
         * __alloc_buddy_huge_page() is checking the global counter,
         * though, we'll note that we're not allowed to exceed surplus
         * and won't grow the pool anywhere else. Not until one of the
         * sysctls are changed, or the surplus pages go out of use.
         */
	min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages;
	min_count = max(count, min_count);
	try_to_free_low(h, min_count, nodes_allowed);
	while (min_count < persistent_huge_pages(h)) {
		if (!free_pool_huge_page(h, nodes_allowed, 0))
			break;
		cond_resched_lock(&hugetlb_lock);
	}
	while (count < persistent_huge_pages(h)) {
		if (!adjust_pool_surplus(h, nodes_allowed, 1))
			break;
	}
out:
	ret = persistent_huge_pages(h);
	spin_unlock(&hugetlb_lock);
	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
Nishanth Aravamudan 160 62.50% 1 8.33%
Andi Kleen 30 11.72% 2 16.67%
Luiz Fernando N. Capitulino 24 9.38% 2 16.67%
Lee Schermerhorn 19 7.42% 3 25.00%
Mel Gorman 11 4.30% 1 8.33%
Masayoshi Mizuma 6 2.34% 1 8.33%
Jia He 4 1.56% 1 8.33%
Naoya Horiguchi 2 0.78% 1 8.33%
Total 256 100.00% 12 100.00%


#define HSTATE_ATTR_RO(_name) \
	static struct kobj_attribute _name##_attr = __ATTR_RO(_name)


#define HSTATE_ATTR(_name) \
	static struct kobj_attribute _name##_attr = \
                __ATTR(_name, 0644, _name##_show, _name##_store)


static struct kobject *hugepages_kobj;

static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE];

static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp);



static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp)
{
	int i;

	for (i = 0; i < HUGE_MAX_HSTATE; i++)
		if (hstate_kobjs[i] == kobj) {
			if (nidp)
				*nidp = NUMA_NO_NODE;
			return &hstates[i];
		}

	return kobj_to_node_hstate(kobj, nidp);
}

Contributors
Person Tokens Prop Commits CommitProp
Nishanth Aravamudan 45 66.18% 1 33.33%
Lee Schermerhorn 21 30.88% 1 33.33%
Andi Kleen 2 2.94% 1 33.33%
Total 68 100.00% 3 100.00%



static ssize_t nr_hugepages_show_common(struct kobject *kobj,
					struct kobj_attribute *attr, char *buf)
{
	struct hstate *h;
	unsigned long nr_huge_pages;
	int nid;

	h = kobj_to_hstate(kobj, &nid);
	if (nid == NUMA_NO_NODE)
		nr_huge_pages = h->nr_huge_pages;
	else
		nr_huge_pages = h->nr_huge_pages_node[nid];

	return sprintf(buf, "%lu\n", nr_huge_pages);
}

Contributors
Person Tokens Prop Commits CommitProp
Nishanth Aravamudan 37 50.00% 1 33.33%
Lee Schermerhorn 37 50.00% 2 66.67%
Total 74 100.00% 3 100.00%



static ssize_t __nr_hugepages_store_common(bool obey_mempolicy,
					   struct hstate *h, int nid,
					   unsigned long count, size_t len)
{
	int err;
	NODEMASK_ALLOC(nodemask_t, nodes_allowed, GFP_KERNEL | __GFP_NORETRY);

	if (hstate_is_gigantic(h) && !gigantic_page_supported()) {
		err = -EINVAL;
		goto out;
	}

	if (nid == NUMA_NO_NODE) {
		/*
                 * global hstate attribute
                 */
		if (!(obey_mempolicy &&
				init_nodemask_of_mempolicy(nodes_allowed))) {
			NODEMASK_FREE(nodes_allowed);
			nodes_allowed = &node_states[N_MEMORY];
		}
	} else if (nodes_allowed) {
		/*
                 * per node hstate attribute: adjust count to global,
                 * but restrict alloc/free to the specified node.
                 */
		count += h->nr_huge_pages - h->nr_huge_pages_node[nid];
		init_nodemask_of_node(nodes_allowed, nid);
	} else
		nodes_allowed = &node_states[N_MEMORY];

	h->max_huge_pages = set_max_huge_pages(h, count, nodes_allowed);

	if (nodes_allowed != &node_states[N_MEMORY])
		NODEMASK_FREE(nodes_allowed);

	return len;
out:
	NODEMASK_FREE(nodes_allowed);
	return err;
}

Contributors
Person Tokens Prop Commits CommitProp
Lee Schermerhorn 102 58.96% 4 36.36%
Nishanth Aravamudan 25 14.45% 1 9.09%
Eric B Munson 24 13.87% 1 9.09%
David Rientjes 12 6.94% 2 18.18%
Luiz Fernando N. Capitulino 7 4.05% 2 18.18%
Lai Jiangshan 3 1.73% 1 9.09%
Total 173 100.00% 11 100.00%



static ssize_t nr_hugepages_store_common(bool obey_mempolicy,
					 struct kobject *kobj, const char *buf,
					 size_t len)
{
	struct hstate *h;
	unsigned long count;
	int nid;
	int err;

	err = kstrtoul(buf, 10, &count);
	if (err)
		return err;

	h = kobj_to_hstate(kobj, &nid);
	return __nr_hugepages_store_common(obey_mempolicy, h, nid, count, len);
}

Contributors
Person Tokens Prop Commits CommitProp
David Rientjes 80 100.00% 1 100.00%
Total 80 100.00% 1 100.00%



static ssize_t nr_hugepages_show(struct kobject *kobj,
				       struct kobj_attribute *attr, char *buf)
{
	return nr_hugepages_show_common(kobj, attr, buf);
}

Contributors
Person Tokens Prop Commits CommitProp
Lee Schermerhorn 30 100.00% 1 100.00%
Total 30 100.00% 1 100.00%



static ssize_t nr_hugepages_store(struct kobject *kobj,
	       struct kobj_attribute *attr, const char *buf, size_t len)
{
	return nr_hugepages_store_common(false, kobj, buf, len);
}
Contributors
Person Tokens Prop Commits CommitProp
Lee Schermerhorn 34 94.44% 1 50.00%
Nishanth Aravamudan 2 5.56% 1 50.00%
Total 36 100.00% 2 100.00%


HSTATE_ATTR(nr_hugepages);

#ifdef CONFIG_NUMA

/*
 * hstate attribute for optionally mempolicy-based constraint on persistent
 * huge page alloc/free.
 */


static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj,
				       struct kobj_attribute *attr, char *buf)
{
	return nr_hugepages_show_common(kobj, attr, buf);
}

Contributors
Person Tokens Prop Commits CommitProp
Lee Schermerhorn 30 100.00% 1 100.00%
Total 30 100.00% 1 100.00%



static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj,
	       struct kobj_attribute *attr, const char *buf, size_t len)
{
	return nr_hugepages_store_common(true, kobj, buf, len);
}
Contributors
Person Tokens Prop Commits CommitProp
Lee Schermerhorn 36 100.00% 1 100.00%
Total 36 100.00% 1 100.00%


HSTATE_ATTR(nr_hugepages_mempolicy);
#endif




static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj,
					struct kobj_attribute *attr, char *buf)
{
	struct hstate *h = kobj_to_hstate(kobj, NULL);
	return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages);
}

Contributors
Person Tokens Prop Commits CommitProp
Nishanth Aravamudan 42 95.45% 1 50.00%
Lee Schermerhorn 2 4.55% 1 50.00%
Total 44 100.00% 2 100.00%



static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj,
		struct kobj_attribute *attr, const char *buf, size_t count)
{
	int err;
	unsigned long input;
	struct hstate *h = kobj_to_hstate(kobj, NULL);

	if (hstate_is_gigantic(h))
		return -EINVAL;

	err = kstrtoul(buf, 10, &input);
	if (err)
		return err;

	spin_lock(&hugetlb_lock);
	h->nr_overcommit_huge_pages = input;
	spin_unlock(&hugetlb_lock);

	return count;
}
Contributors
Person Tokens Prop Commits CommitProp
Nishanth Aravamudan 79 84.04% 1 16.67%
Eric B Munson 9 9.57% 2 33.33%
Luiz Fernando N. Capitulino 3 3.19% 1 16.67%
Lee Schermerhorn 2 2.13% 1 16.67%
Jingoo Han 1 1.06% 1 16.67%
Total 94 100.00% 6 100.00%


HSTATE_ATTR(nr_overcommit_hugepages);



static ssize_t free_hugepages_show(struct kobject *kobj,
					struct kobj_attribute *attr, char *buf)
{
	struct hstate *h;
	unsigned long free_huge_pages;
	int nid;

	h = kobj_to_hstate(kobj, &nid);
	if (nid == NUMA_NO_NODE)
		free_huge_pages = h->free_huge_pages;
	else
		free_huge_pages = h->free_huge_pages_node[nid];

	return sprintf(buf, "%lu\n", free_huge_pages);
}
Contributors
Person Tokens Prop Commits CommitProp
Nishanth Aravamudan 37 50.00% 1 33.33%
Lee Schermerhorn 36 48.65% 1 33.33%
Andi Kleen 1 1.35% 1 33.33%
Total 74 100.00% 3 100.00%


HSTATE_ATTR_RO(free_hugepages);



static ssize_t resv_hugepages_show(struct kobject *kobj,
					struct kobj_attribute *attr, char *buf)
{
	struct hstate *h = kobj_to_hstate(kobj, NULL);
	return sprintf(buf, "%lu\n", h->resv_huge_pages);
}
Contributors
Person Tokens Prop Commits CommitProp
Nishanth Aravamudan 40 90.91% 1 33.33%
Lee Schermerhorn 2 4.55% 1 33.33%
Andi Kleen 2 4.55% 1 33.33%
Total 44 100.00% 3 100.00%


HSTATE_ATTR_RO(resv_hugepages);



static ssize_t surplus_hugepages_show(struct kobject *kobj,
					struct kobj_attribute *attr, char *buf)
{
	struct hstate *h;
	unsigned long surplus_huge_pages;
	int nid;

	h = kobj_to_hstate(kobj, &nid);
	if (nid == NUMA_NO_NODE)
		surplus_huge_pages = h->surplus_huge_pages;
	else
		surplus_huge_pages = h->surplus_huge_pages_node[nid];

	return sprintf(buf, "%lu\n", surplus_huge_pages);
}
Contributors
Person Tokens Prop Commits CommitProp
Lee Schermerhorn 36 48.65% 1 20.00%
Nishanth Aravamudan 25 33.78% 1 20.00%
David Gibson 9 12.16% 1 20.00%
Andy Whitcroft 3 4.05% 1 20.00%
Andi Kleen 1 1.35% 1 20.00%
Total 74 100.00% 5 100.00%


HSTATE_ATTR_RO(surplus_hugepages);


static struct attribute *hstate_attrs[] = {
	&nr_hugepages_attr.attr,
	&nr_overcommit_hugepages_attr.attr,
	&free_hugepages_attr.attr,
	&resv_hugepages_attr.attr,
	&surplus_hugepages_attr.attr,
#ifdef CONFIG_NUMA
	&nr_hugepages_mempolicy_attr.attr,
#endif
	NULL,
};


static struct attribute_group hstate_attr_group = {
	.attrs = hstate_attrs,
};



static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent,
				    struct kobject **hstate_kobjs,
				    struct attribute_group *hstate_attr_group)
{
	int retval;
	int hi = hstate_index(h);

	hstate_kobjs[hi] = kobject_create_and_add(h->name, parent);
	if (!hstate_kobjs[hi])
		return -ENOMEM;

	retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group);
	if (retval)
		kobject_put(hstate_kobjs[hi]);

	return retval;
}

Contributors
Person Tokens Prop Commits CommitProp
Nishanth Aravamudan 42 46.15% 1 20.00%
Lee Schermerhorn 34 37.36% 1 20.00%
David Gibson 6 6.59% 1 20.00%
Andy Whitcroft 6 6.59% 1 20.00%
Aneesh Kumar K.V 3 3.30% 1 20.00%
Total 91 100.00% 5 100.00%



static void __init hugetlb_sysfs_init(void)
{
	struct hstate *h;
	int err;

	hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj);
	if (!hugepages_kobj)
		return;

	for_each_hstate(h) {
		err = hugetlb_sysfs_add_hstate(h, hugepages_kobj,
					 hstate_kobjs, &hstate_attr_group);
		if (err)
			pr_err("Hugetlb: Unable to add hstate %s", h->name);
	}
}

Contributors
Person Tokens Prop Commits CommitProp
Lee Schermerhorn 64 98.46% 1 50.00%
Andrew Morton 1 1.54% 1 50.00%
Total 65 100.00% 2 100.00%

#ifdef CONFIG_NUMA

/*
 * node_hstate/s - associate per node hstate attributes, via their kobjects,
 * with node devices in node_devices[] using a parallel array.  The array
 * index of a node device or _hstate == node id.
 * This is here to avoid any static dependency of the node device driver, in
 * the base kernel, on the hugetlb module.
 */

struct node_hstate {
	
struct kobject		*hugepages_kobj;
	
struct kobject		*hstate_kobjs[HUGE_MAX_HSTATE];
};

static struct node_hstate node_hstates[MAX_NUMNODES];

/*
 * A subset of global hstate attributes for node devices
 */

static struct attribute *per_node_hstate_attrs[] = {
	&nr_hugepages_attr.attr,
	&free_hugepages_attr.attr,
	&surplus_hugepages_attr.attr,
	NULL,
};


static struct attribute_group per_node_hstate_attr_group = {
	.attrs = per_node_hstate_attrs,
};

/*
 * kobj_to_node_hstate - lookup global hstate for node device hstate attr kobj.
 * Returns node id via non-NULL nidp.
 */


static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp)
{
	int nid;

	for (nid = 0; nid < nr_node_ids; nid++) {
		struct node_hstate *nhs = &node_hstates[nid];
		int i;
		for (i = 0; i < HUGE_MAX_HSTATE; i++)
			if (nhs->hstate_kobjs[i] == kobj) {
				if (nidp)
					*nidp = nid;
				return &hstates[i];
			}
	}

	BUG();
	return NULL;
}

Contributors
Person Tokens Prop Commits CommitProp
Lee Schermerhorn 97 100.00% 1 100.00%
Total 97 100.00% 1 100.00%

/*
 * Unregister hstate attributes from a single node device.
 * No-op if no hstate attributes attached.
 */


static void hugetlb_unregister_node(struct node *node)
{
	struct hstate *h;
	struct node_hstate *nhs = &node_hstates[node->dev.id];

	if (!nhs->hugepages_kobj)
		return;		/* no hstate attributes */

	for_each_hstate(h) {
		int idx = hstate_index(h);
		if (nhs->hstate_kobjs[idx]) {
			kobject_put(nhs->hstate_kobjs[idx]);
			nhs->hstate_kobjs[idx] = NULL;
		}
	}

	kobject_put(nhs->hugepages_kobj);
	nhs->hugepages_kobj = NULL;
}


Contributors
Person Tokens Prop Commits CommitProp
Lee Schermerhorn 78 80.41% 2 28.57%
Aneesh Kumar K.V 13 13.40% 1 14.29%
Andy Whitcroft 3 3.09% 1 14.29%
Kay Sievers 1 1.03% 1 14.29%
Claudiu Ghioc 1 1.03% 1 14.29%
Nishanth Aravamudan 1 1.03% 1 14.29%
Total 97 100.00% 7 100.00%

/*
 * Register hstate attributes for a single node device.
 * No-op if attributes already registered.
 */


static void hugetlb_register_node(struct node *node)
{
	struct hstate *h;
	struct node_hstate *nhs = &node_hstates[node->dev.id];
	int err;

	if (nhs->hugepages_kobj)
		return;		/* already allocated */

	nhs->hugepages_kobj = kobject_create_and_add("hugepages",
							&node->dev.kobj);
	if (!nhs->hugepages_kobj)
		return;

	for_each_hstate(h) {
		err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj,
						nhs->hstate_kobjs,
						&per_node_hstate_attr_group);
		if (err) {
			pr_err("Hugetlb: Unable to add hstate %s for node %d\n",
				h->name, node->dev.id);
			hugetlb_unregister_node(node);
			break;
		}
	}
}

Contributors
Person Tokens Prop Commits CommitProp
Lee Schermerhorn 68 58.12% 1 7.69%
Nishanth Aravamudan 20 17.09% 1 7.69%
David Gibson 9 7.69% 2 15.38%
Andi Kleen 7 5.98% 2 15.38%
Hugh Dickins 5 4.27% 2 15.38%
Kay Sievers 3 2.56% 1 7.69%
Andrew Morton 2 1.71% 1 7.69%
Gerald Schaefer 1 0.85% 1 7.69%
Claudiu Ghioc 1 0.85% 1 7.69%
Andy Whitcroft 1 0.85% 1 7.69%
Total 117 100.00% 13 100.00%

/*
 * hugetlb init time:  register hstate attributes for all registered node
 * devices of nodes that have memory.  All on-line nodes should have
 * registered their associated device by this time.
 */


static void __init hugetlb_register_all_nodes(void)
{
	int nid;

	for_each_node_state(nid, N_MEMORY) {
		struct node *node = node_devices[nid];
		if (node->dev.id == nid)
			hugetlb_register_node(node);
	}

	/*
         * Let the node device driver know we're here so it can
         * [un]register hstate attributes on node hotplug.
         */
	register_hugetlbfs_with_node(hugetlb_register_node,
				     hugetlb_unregister_node);
}
Contributors
Person Tokens Prop Commits CommitProp
Lee Schermerhorn 46 86.79% 2 28.57%
Kay Sievers 2 3.77% 1 14.29%
David Gibson 2 3.77% 1 14.29%
Hugh Dickins 1 1.89% 1 14.29%
Luiz Fernando N. Capitulino 1 1.89% 1 14.29%
Lai Jiangshan 1 1.89% 1 14.29%
Total 53 100.00% 7 100.00%

#else	/* !CONFIG_NUMA */



static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp)
{
	BUG();
	if (nidp)
		*nidp = -1;
	return NULL;
}

Contributors
Person Tokens Prop Commits CommitProp
Lee Schermerhorn 32 96.97% 1 50.00%
David Gibson 1 3.03% 1 50.00%
Total 33 100.00% 2 100.00%



static void hugetlb_register_all_nodes(void) { }

Contributors
Person Tokens Prop Commits CommitProp
Lee Schermerhorn 7 100.00% 1 100.00%
Total 7 100.00% 1 100.00%

#endif



static int __init hugetlb_init(void)
{
	int i;

	if (!hugepages_supported())
		return 0;

	if (!size_to_hstate(default_hstate_size)) {
		if (default_hstate_size != 0) {
			pr_err("HugeTLB: unsupported default_hugepagesz %lu. Reverting to %lu\n",
			       default_hstate_size, HPAGE_SIZE);
		}

		default_hstate_size = HPAGE_SIZE;
		if (!size_to_hstate(default_hstate_size))
			hugetlb_add_hstate(HUGETLB_PAGE_ORDER);
	}
	default_hstate_idx = hstate_index(size_to_hstate(default_hstate_size));
	if (default_hstate_max_huge_pages) {
		if (!default_hstate.max_huge_pages)
			default_hstate.max_huge_pages = default_hstate_max_huge_pages;
	}

	hugetlb_init_hstates();
	gather_bootmem_prealloc();
	report_hugepages();

	hugetlb_sysfs_init();
	hugetlb_register_all_nodes();
	hugetlb_cgroup_file_init();

#ifdef CONFIG_SMP
	num_fault_mutexes = roundup_pow_of_two(8 * num_possible_cpus());
#else
	num_fault_mutexes = 1;
#endif
	hugetlb_fault_mutex_table =
		kmalloc(sizeof(struct mutex) * num_fault_mutexes, GFP_KERNEL);
	BUG_ON(!hugetlb_fault_mutex_table);

	for (i = 0; i < num_fault_mutexes; i++)
		mutex_init(&hugetlb_fault_mutex_table[i]);
	return 0;
}
Contributors
Person Tokens Prop Commits CommitProp
Davidlohr Bueso A 64 35.75% 1 6.67%
Nishanth Aravamudan 35 19.55% 2 13.33%
Nicholas Piggin 24 13.41% 1 6.67%
Liam R. Howlett 17 9.50% 1 6.67%
Vaishali Thakkar 9 5.03% 1 6.67%
Benjamin Herrenschmidt 6 3.35% 1 6.67%
Andy Whitcroft 5 2.79% 1 6.67%
Andi Kleen 5 2.79% 2 13.33%
Jianguo Wu 3 1.68% 1 6.67%
Aneesh Kumar K.V 3 1.68% 1 6.67%
Lee Schermerhorn 3 1.68% 1 6.67%
Mike Kravetz 3 1.68% 1 6.67%
Andrew Morton 2 1.12% 1 6.67%
Total 179 100.00% 15 100.00%


subsys_initcall(hugetlb_init);

/* Should be called on processing a hugepagesz=... option */


void __init hugetlb_bad_size(void)
{
	parsed_valid_hugepagesz = false;
}

Contributors
Person Tokens Prop Commits CommitProp
Vaishali Thakkar 12 100.00% 1 100.00%
Total 12 100.00% 1 100.00%



void __init hugetlb_add_hstate(unsigned int order)
{
	struct hstate *h;
	unsigned long i;

	if (size_to_hstate(PAGE_SIZE << order)) {
		pr_warn("hugepagesz= specified twice, ignoring\n");
		return;
	}
	BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE);
	BUG_ON(order == 0);
	h = &hstates[hugetlb_max_hstate++];
	h->order = order;
	h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1);
	h->nr_huge_pages = 0;
	h->free_huge_pages = 0;
	for (i = 0; i < MAX_NUMNODES; ++i)
		INIT_LIST_HEAD(&h->hugepage_freelists[i]);
	INIT_LIST_HEAD(&h->hugepage_activelist);
	h->next_nid_to_alloc = first_memory_node;
	h->next_nid_to_free = first_memory_node;
	snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB",
					huge_page_size(h)/1024);

	parsed_hstate = h;
}

Contributors
Person Tokens Prop Commits CommitProp
Nishanth Aravamudan 70 43.21% 1 7.14%
Andi Kleen 54 33.33% 2 14.29%
Aneesh Kumar K.V 10 6.17% 2 14.29%
Lee Schermerhorn 6 3.70% 1 7.14%
Andy Whitcroft 6 3.70% 1 7.14%
Andrew Morton 5 3.09% 2 14.29%
David Gibson 4 2.47% 1 7.14%
Hugh Dickins 3 1.85% 1 7.14%
Kenneth W. Chen 2 1.23% 1 7.14%
Joe Perches 1 0.62% 1 7.14%
Kirill A. Shutemov 1 0.62% 1 7.14%
Total 162 100.00% 14 100.00%



static int __init hugetlb_nrpages_setup(char *s)
{
	unsigned long *mhp;
	static unsigned long *last_mhp;

	if (!parsed_valid_hugepagesz) {
		pr_warn("hugepages = %s preceded by "
			"an unsupported hugepagesz, ignoring\n", s);
		parsed_valid_hugepagesz = true;
		return 1;
	}
	/*
         * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter yet,
         * so this hugepages= parameter goes to the "default hstate".
         */
	else if (!hugetlb_max_hstate)
		mhp = &default_hstate_max_huge_pages;
	else
		mhp = &parsed_hstate->max_huge_pages;

	if (mhp == last_mhp) {
		pr_warn("hugepages= specified twice without interleaving hugepagesz=, ignoring\n");
		return 1;
	}

	if (sscanf(s, "%lu", mhp) <= 0)
		*mhp = 0;

	/*
         * Global state is always initialized later in hugetlb_init.
         * But we need to allocate >= MAX_ORDER hstates here early to still
         * use the bootmem allocator.
         */
	if (hugetlb_max_hstate && parsed_hstate->order >= MAX_ORDER)
		hugetlb_hstate_alloc_pages(parsed_hstate);

	last_mhp = mhp;

	return 1;
}
Contributors
Person Tokens Prop Commits CommitProp
Andi Kleen 40 33.06% 2 22.22%
Nishanth Aravamudan 38 31.40% 1 11.11%
Vaishali Thakkar 23 19.01% 1 11.11%
Mel Gorman 10 8.26% 1 11.11%
Andy Whitcroft 4 3.31% 1 11.11%
Aneesh Kumar K.V 3 2.48% 1 11.11%
Joe Perches 2 1.65% 1 11.11%
Nicholas Piggin 1 0.83% 1 11.11%
Total 121 100.00% 9 100.00%

__setup("hugepages=", hugetlb_nrpages_setup);



static int __init hugetlb_default_setup(char *s)
{
	default_hstate_size = memparse(s, &s);
	return 1;
}
Contributors
Person Tokens Prop Commits CommitProp
Nicholas Piggin 24 100.00% 1 100.00%
Total 24 100.00% 1 100.00%

__setup("default_hugepagesz=", hugetlb_default_setup);



static unsigned int cpuset_mems_nr(unsigned int *array)
{
	int node;
	unsigned int nr = 0;

	for_each_node_mask(node, cpuset_current_mems_allowed)
		nr += array[node];

	return nr;
}

Contributors
Person Tokens Prop Commits CommitProp
Nishanth Aravamudan 37 100.00% 1 100.00%
Total 37 100.00% 1 100.00%

#ifdef CONFIG_SYSCTL


static int hugetlb_sysctl_handler_common(bool obey_mempolicy,
			 struct ctl_table *table, int write,
			 void __user *buffer, size_t *length, loff_t *ppos)
{
	struct hstate *h = &default_hstate;
	unsigned long tmp = h->max_huge_pages;
	int ret;

	if (!hugepages_supported())
		return -EOPNOTSUPP;

	table->data = &tmp;
	table->maxlen = sizeof(unsigned long);
	ret = proc_doulongvec_minmax(table, write, buffer, length, ppos);
	if (ret)
		goto out;

	if (write)
		ret = __nr_hugepages_store_common(obey_mempolicy, h,
						  NUMA_NO_NODE, tmp, *length);
out:
	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 38 30.89% 1 11.11%
Andi Kleen 36 29.27% 1 11.11%
Michal Hocko 15 12.20% 1 11.11%
David Rientjes 12 9.76% 1 11.11%
Nishanth Aravamudan 9 7.32% 1 11.11%
Mel Gorman 6 4.88% 1 11.11%
Lee Schermerhorn 6 4.88% 2 22.22%
Jan Stancek 1 0.81% 1 11.11%
Total 123 100.00% 9 100.00%



int hugetlb_sysctl_handler(struct ctl_table *table, int write,
			  void __user *buffer, size_t *length, loff_t *ppos)
{

	return hugetlb_sysctl_handler_common(false, table, write,
							buffer, length, ppos);
}

Contributors
Person Tokens Prop Commits CommitProp
Lee Schermerhorn 42 100.00% 1 100.00%
Total 42 100.00% 1 100.00%

#ifdef CONFIG_NUMA


int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write,
			  void __user *buffer, size_t *length, loff_t *ppos)
{
	return hugetlb_sysctl_handler_common(true, table, write,
							buffer, length, ppos);
}
Contributors
Person Tokens Prop Commits CommitProp
Lee Schermerhorn 42 100.00% 1 100.00%
Total 42 100.00% 1 100.00%

#endif /* CONFIG_NUMA */



int hugetlb_overcommit_handler(struct ctl_table *table, int write,
			void __user *buffer,
			size_t *length, loff_t *ppos)
{
	struct hstate *h = &default_hstate;
	unsigned long tmp;
	int ret;

	if (!hugepages_supported())
		return -EOPNOTSUPP;

	tmp = h->nr_overcommit_huge_pages;

	if (write && hstate_is_gigantic(h))
		return -EINVAL;

	table->data = &tmp;
	table->maxlen = sizeof(unsigned long);
	ret = proc_doulongvec_minmax(table, write, buffer, length, ppos);
	if (ret)
		goto out;

	if (write) {
		spin_lock(&hugetlb_lock);
		h->nr_overcommit_huge_pages = tmp;
		spin_unlock(&hugetlb_lock);
	}
out:
	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 44 31.88% 1 8.33%
Andi Kleen 44 31.88% 2 16.67%
Michal Hocko 15 10.87% 1 8.33%
Eric B Munson 10 7.25% 1 8.33%
Nishanth Aravamudan 9 6.52% 1 8.33%
David Gibson 7 5.07% 1 8.33%
Luiz Fernando N. Capitulino 3 2.17% 1 8.33%
Ken Chen 3 2.17% 1 8.33%
Hugh Dickins 1 0.72% 1 8.33%
Kenneth W. Chen 1 0.72% 1 8.33%
Jan Stancek 1 0.72% 1 8.33%
Total 138 100.00% 12 100.00%

#endif /* CONFIG_SYSCTL */



void hugetlb_report_meminfo(struct seq_file *m)
{
	struct hstate *h = &default_hstate;
	if (!hugepages_supported())
		return;
	seq_printf(m,
			"HugePages_Total:   %5lu\n"
			"HugePages_Free:    %5lu\n"
			"HugePages_Rsvd:    %5lu\n"
			"HugePages_Surp:    %5lu\n"
			"Hugepagesize:   %8lu kB\n",
			h->nr_huge_pages,
			h->free_huge_pages,
			h->resv_huge_pages,
			h->surplus_huge_pages,
			1UL << (huge_page_order(h) + PAGE_SHIFT - 10));
}

Contributors
Person Tokens Prop Commits CommitProp
Andi Kleen 28 43.08% 1 14.29%
Andy Whitcroft 10 15.38% 1 14.29%
Alexey Dobriyan 7 10.77% 1 14.29%
Nishanth Aravamudan 7 10.77% 1 14.29%
Rik Van Riel 5 7.69% 1 14.29%
David Gibson 4 6.15% 1 14.29%
Kenneth W. Chen 4 6.15% 1 14.29%
Total 65 100.00% 7 100.00%



int hugetlb_report_node_meminfo(int nid, char *buf)
{
	struct hstate *h = &default_hstate;
	if (!hugepages_supported())
		return 0;
	return sprintf(buf,
		"Node %d HugePages_Total: %5u\n"
		"Node %d HugePages_Free:  %5u\n"
		"Node %d HugePages_Surp:  %5u\n",
		nid, h->nr_huge_pages_node[nid],
		nid, h->free_huge_pages_node[nid],
		nid, h->surplus_huge_pages_node[nid]);
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 33 50.00% 1 20.00%
Andi Kleen 14 21.21% 1 20.00%
Nishanth Aravamudan 9 13.64% 1 20.00%
Kenneth W. Chen 7 10.61% 1 20.00%
Mel Gorman 3 4.55% 1 20.00%
Total 66 100.00% 5 100.00%



void hugetlb_show_meminfo(void)
{
	struct hstate *h;
	int nid;

	if (!hugepages_supported())
		return;

	for_each_node_state(nid, N_MEMORY)
		for_each_hstate(h)
			pr_info("Node %d hugepages_total=%u hugepages_free=%u hugepages_surp=%u hugepages_size=%lukB\n",
				nid,
				h->nr_huge_pages_node[nid],
				h->free_huge_pages_node[nid],
				h->surplus_huge_pages_node[nid],
				1UL << (huge_page_order(h) + PAGE_SHIFT - 10));
}

Contributors
Person Tokens Prop Commits CommitProp
David Rientjes 66 90.41% 1 50.00%
Nishanth Aravamudan 7 9.59% 1 50.00%
Total 73 100.00% 2 100.00%



void hugetlb_report_usage(struct seq_file *m, struct mm_struct *mm)
{
	seq_printf(m, "HugetlbPages:\t%8lu kB\n",
		   atomic_long_read(&mm->hugetlb_usage) << (PAGE_SHIFT - 10));
}

Contributors
Person Tokens Prop Commits CommitProp
Naoya Horiguchi 36 100.00% 1 100.00%
Total 36 100.00% 1 100.00%

/* Return the number pages of memory we physically have, in PAGE_SIZE units. */


unsigned long hugetlb_total_pages(void)
{
	struct hstate *h;
	unsigned long nr_total_pages = 0;

	for_each_hstate(h)
		nr_total_pages += h->nr_huge_pages * pages_per_huge_page(h);
	return nr_total_pages;
}

Contributors
Person Tokens Prop Commits CommitProp
Wanpeng Li 14 37.84% 1 33.33%
Andi Kleen 12 32.43% 1 33.33%
Andy Whitcroft 11 29.73% 1 33.33%
Total 37 100.00% 3 100.00%



static int hugetlb_acct_memory(struct hstate *h, long delta)
{
	int ret = -ENOMEM;

	spin_lock(&hugetlb_lock);
	/*
         * When cpuset is configured, it breaks the strict hugetlb page
         * reservation as the accounting is done on a global variable. Such
         * reservation is completely rubbish in the presence of cpuset because
         * the reservation is not checked against page availability for the
         * current cpuset. Application can still potentially OOM'ed by kernel
         * with lack of free htlb page in cpuset that the task is in.
         * Attempt to enforce strict accounting with cpuset is almost
         * impossible (or too ugly) because cpuset is too fluid that
         * task or memory node can be dynamically moved between cpusets.
         *
         * The change of semantics for shared hugetlb mapping with cpuset is
         * undesirable. However, in order to preserve some of the semantics,
         * we fall back to check against current free page availability as
         * a best attempt and hopefully to minimize the impact of changing
         * semantics that cpuset has.
         */
	if (delta > 0) {
		if (gather_surplus_pages(h, delta) < 0)
			goto out;

		if (delta > cpuset_mems_nr(h->free_huge_pages_node)) {
			return_unused_surplus_pages(h, delta);
			goto out;
		}
	}

	ret = 0;
	if (delta < 0)
		return_unused_surplus_pages(h, (unsigned long) -delta);

out:
	spin_unlock(&hugetlb_lock);
	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 72 68.57% 1 25.00%
Mel Gorman 15 14.29% 1 25.00%
Andi Kleen 13 12.38% 1 25.00%
David Gibson 5 4.76% 1 25.00%
Total 105 100.00% 4 100.00%



static void hugetlb_vm_op_open(struct vm_area_struct *vma)
{
	struct resv_map *resv = vma_resv_map(vma);

	/*
         * This new VMA should share its siblings reservation map if present.
         * The VMA will only ever have a valid reservation map pointer where
         * it is being copied for another still existing VMA.  As that VMA
         * has a reference to the reservation map it cannot disappear until
         * after this open call completes.  It is therefore safe to take a
         * new reference here without additional locking.
         */
	if (resv && is_vma_resv_set(vma, HPAGE_RESV_OWNER))
		kref_get(&resv->refs);
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 30 73.17% 1 25.00%
JoonSoo Kim 10 24.39% 2 50.00%
Lucas De Marchi 1 2.44% 1 25.00%
Total 41 100.00% 4 100.00%



static void hugetlb_vm_op_close(struct vm_area_struct *vma)
{
	struct hstate *h = hstate_vma(vma);
	struct resv_map *resv = vma_resv_map(vma);
	struct hugepage_subpool *spool = subpool_vma(vma);
	unsigned long reserve, start, end;
	long gbl_reserve;

	if (!resv || !is_vma_resv_set(vma, HPAGE_RESV_OWNER))
		return;

	start = vma_hugecache_offset(h, vma, vma->vm_start);
	end = vma_hugecache_offset(h, vma, vma->vm_end);

	reserve = (end - start) - region_count(resv, start, end);

	kref_put(&resv->refs, resv_map_release);

	if (reserve) {
		/*
                 * Decrement reserve counts.  The global reserve count may be
                 * adjusted if the subpool has a minimum size.
                 */
		gbl_reserve = hugepage_subpool_put_pages(spool, reserve);
		hugetlb_acct_memory(h, -gbl_reserve);
	}
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 67 46.85% 2 18.18%
JoonSoo Kim 22 15.38% 3 27.27%
Andi Kleen 15 10.49% 1 9.09%
Mike Kravetz 12 8.39% 1 9.09%
David Gibson 10 6.99% 1 9.09%
Mel Gorman 9 6.29% 1 9.09%
Adam Litke 6 4.20% 1 9.09%
Johannes Weiner 2 1.40% 1 9.09%
Total 143 100.00% 11 100.00%

/*
 * We cannot handle pagefaults against hugetlb pages at all.  They cause
 * handle_mm_fault() to try to instantiate regular-sized pages in the
 * hugegpage VMA.  do_page_fault() is supposed to trap this, so BUG is we get
 * this far.
 */


static int hugetlb_vm_op_fault(struct vm_fault *vmf)
{
	BUG();
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 10 58.82% 1 50.00%
Mel Gorman 7 41.18% 1 50.00%
Total 17 100.00% 2 100.00%


const struct vm_operations_struct hugetlb_vm_ops = {
	.fault = hugetlb_vm_op_fault,
	.open = hugetlb_vm_op_open,
	.close = hugetlb_vm_op_close,
};



static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page,
				int writable)
{
	pte_t entry;

	if (writable) {
		entry = huge_pte_mkwrite(huge_pte_mkdirty(mk_huge_pte(page,
					 vma->vm_page_prot)));
	} else {
		entry = huge_pte_wrprotect(mk_huge_pte(page,
					   vma->vm_page_prot));
	}
	entry = pte_mkyoung(entry);
	entry = pte_mkhuge(entry);
	entry = arch_make_huge_pte(entry, vma, page, writable);

	return entry;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 51 55.43% 1 14.29%
David Gibson 14 15.22% 1 14.29%
Chris Metcalf 13 14.13% 1 14.29%
Mel Gorman 6 6.52% 1 14.29%
Gerald Schaefer 4 4.35% 1 14.29%
Christoph Lameter 2 2.17% 1 14.29%
Adam Litke 2 2.17% 1 14.29%
Total 92 100.00% 7 100.00%



static void set_huge_ptep_writable(struct vm_area_struct *vma,
				   unsigned long address, pte_t *ptep)
{
	pte_t entry;

	entry = huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(ptep)));
	if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1))
		update_mmu_cache(vma, address, ptep);
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 37 62.71% 1 20.00%
Mel Gorman 17 28.81% 1 20.00%
Gerald Schaefer 2 3.39% 1 20.00%
David Gibson 2 3.39% 1 20.00%
Russell King 1 1.69% 1 20.00%
Total 59 100.00% 5 100.00%



bool is_hugetlb_entry_migration(pte_t pte)
{
	swp_entry_t swp;

	if (huge_pte_none(pte) || pte_present(pte))
		return false;
	swp = pte_to_swp_entry(pte);
	if (non_swap_entry(swp) && is_migration_entry(swp))
		return true;
	else
		return false;
}

Contributors
Person Tokens Prop Commits CommitProp
Naoya Horiguchi 48 92.31% 1 50.00%
Aneesh Kumar K.V 4 7.69% 1 50.00%
Total 52 100.00% 2 100.00%



static int is_hugetlb_entry_hwpoisoned(pte_t pte)
{
	swp_entry_t swp;

	if (huge_pte_none(pte) || pte_present(pte))
		return 0;
	swp = pte_to_swp_entry(pte);
	if (non_swap_entry(swp) && is_hwpoison_entry(swp))
		return 1;
	else
		return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Naoya Horiguchi 53 100.00% 1 100.00%
Total 53 100.00% 1 100.00%



int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
			    struct vm_area_struct *vma)
{
	pte_t *src_pte, *dst_pte, entry;
	struct page *ptepage;
	unsigned long addr;
	int cow;
	struct hstate *h = hstate_vma(vma);
	unsigned long sz = huge_page_size(h);
	unsigned long mmun_start;	/* For mmu_notifiers */
	unsigned long mmun_end;		/* For mmu_notifiers */
	int ret = 0;

	cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;

	mmun_start = vma->vm_start;
	mmun_end = vma->vm_end;
	if (cow)
		mmu_notifier_invalidate_range_start(src, mmun_start, mmun_end);

	for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) {
		spinlock_t *src_ptl, *dst_ptl;
		src_pte = huge_pte_offset(src, addr, sz);
		if (!src_pte)
			continue;
		dst_pte = huge_pte_alloc(dst, addr, sz);
		if (!dst_pte) {
			ret = -ENOMEM;
			break;
		}

		/* If the pagetables are shared don't copy or take references */
		if (dst_pte == src_pte)
			continue;

		dst_ptl = huge_pte_lock(h, dst, dst_pte);
		src_ptl = huge_pte_lockptr(h, src, src_pte);
		spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
		entry = huge_ptep_get(src_pte);
		if (huge_pte_none(entry)) { /* skip none entry */
			;
		} else if (unlikely(is_hugetlb_entry_migration(entry) ||
				    is_hugetlb_entry_hwpoisoned(entry))) {
			swp_entry_t swp_entry = pte_to_swp_entry(entry);

			if (is_write_migration_entry(swp_entry) && cow) {
				/*
                                 * COW mappings require pages in both
                                 * parent and child to be set to read.
                                 */
				make_migration_entry_read(&swp_entry);
				entry = swp_entry_to_pte(swp_entry);
				set_huge_swap_pte_at(src, addr, src_pte,
						     entry, sz);
			}
			set_huge_swap_pte_at(dst, addr, dst_pte, entry, sz);
		} else {
			if (cow) {
				huge_ptep_set_wrprotect(src, addr, src_pte);
				mmu_notifier_invalidate_range(src, mmun_start,
								   mmun_end);
			}
			entry = huge_ptep_get(src_pte);
			ptepage = pte_page(entry);
			get_page(ptepage);
			page_dup_rmap(ptepage, true);
			set_huge_pte_at(dst, addr, dst_pte, entry);
			hugetlb_count_add(pages_per_huge_page(h), dst);
		}
		spin_unlock(src_ptl);
		spin_unlock(dst_ptl);
	}

	if (cow)
		mmu_notifier_invalidate_range_end(src, mmun_start, mmun_end);

	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 141 33.89% 1 5.88%
Naoya Horiguchi 100 24.04% 4 23.53%
Andreas Sandberg 62 14.90% 1 5.88%
David Gibson 34 8.17% 1 5.88%
Kirill A. Shutemov 30 7.21% 2 11.76%
Andi Kleen 22 5.29% 1 5.88%
Joerg Roedel 11 2.64% 1 5.88%
Punit Agrawal 8 1.92% 2 11.76%
Gerald Schaefer 4 0.96% 2 11.76%
Nicholas Piggin 3 0.72% 1 5.88%
Atsushi Nemoto 1 0.24% 1 5.88%
Total 416 100.00% 17 100.00%



void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
			    unsigned long start, unsigned long end,
			    struct page *ref_page)
{
	struct mm_struct *mm = vma->vm_mm;
	unsigned long address;
	pte_t *ptep;
	pte_t pte;
	spinlock_t *ptl;
	struct page *page;
	struct hstate *h = hstate_vma(vma);
	unsigned long sz = huge_page_size(h);
	const unsigned long mmun_start = start;	/* For mmu_notifiers */
	const unsigned long mmun_end   = end;	/* For mmu_notifiers */

	WARN_ON(!is_vm_hugetlb_page(vma));
	BUG_ON(start & ~huge_page_mask(h));
	BUG_ON(end & ~huge_page_mask(h));

	/*
         * This is a hugetlb vma, all the pte entries should point
         * to huge page.
         */
	tlb_remove_check_page_size_change(tlb, sz);
	tlb_start_vma(tlb, vma);
	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
	address = start;
	for (; address < end; address += sz) {
		ptep = huge_pte_offset(mm, address, sz);
		if (!ptep)
			continue;

		ptl = huge_pte_lock(h, mm, ptep);
		if (huge_pmd_unshare(mm, &address, ptep)) {
			spin_unlock(ptl);
			continue;
		}

		pte = huge_ptep_get(ptep);
		if (huge_pte_none(pte)) {
			spin_unlock(ptl);
			continue;
		}

		/*
                 * Migrating hugepage or HWPoisoned hugepage is already
                 * unmapped and its refcount is dropped, so just clear pte here.
                 */
		if (unlikely(!pte_present(pte))) {
			huge_pte_clear(mm, address, ptep, sz);
			spin_unlock(ptl);
			continue;
		}

		page = pte_page(pte);
		/*
                 * If a reference page is supplied, it is because a specific
                 * page is being unmapped, not a range. Ensure the page we
                 * are about to unmap is the actual page of interest.
                 */
		if (ref_page) {
			if (page != ref_page) {
				spin_unlock(ptl);
				continue;
			}
			/*
                         * Mark the VMA as having unmapped its page so that
                         * future faults in this VMA will fail rather than
                         * looking like data was lost
                         */
			set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED);
		}

		pte = huge_ptep_get_and_clear(mm, address, ptep);
		tlb_remove_huge_tlb_entry(h, tlb, ptep, address);
		if (huge_pte_dirty(pte))
			set_page_dirty(page);

		hugetlb_count_sub(pages_per_huge_page(h), mm);
		page_remove_rmap(page, true);

		spin_unlock(ptl);
		tlb_remove_page_size(tlb, page, huge_page_size(h));
		/*
                 * Bail out after unmapping reference page if supplied
                 */
		if (ref_page)
			break;
	}
	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
	tlb_end_vma(tlb, vma);
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 110 28.13% 2 6.67%
Aneesh Kumar K.V 83 21.23% 5 16.67%
Andi Kleen 27 6.91% 1 3.33%
Kirill A. Shutemov 23 5.88% 2 6.67%
Naoya Horiguchi 23 5.88% 3 10.00%
Sagi Grimberg 20 5.12% 1 3.33%
Hillf Danton 19 4.86% 2 6.67%
Adam Litke 18 4.60% 3 10.00%
David Gibson 14 3.58% 2 6.67%
Andrea Arcangeli 14 3.58% 1 3.33%
Mel Gorman 14 3.58% 1 3.33%
Christoph Lameter 12 3.07% 2 6.67%
Hugh Dickins 6 1.53% 1 3.33%
Punit Agrawal 4 1.02% 2 6.67%
Gerald Schaefer 2 0.51% 1 3.33%
Al Viro 2 0.51% 1 3.33%
Total 391 100.00% 30 100.00%



void __unmap_hugepage_range_final(struct mmu_gather *tlb,
			  struct vm_area_struct *vma, unsigned long start,
			  unsigned long end, struct page *ref_page)
{
	__unmap_hugepage_range(tlb, vma, start, end, ref_page);

	/*
         * Clear this flag so that x86's huge_pmd_share page_table_shareable
         * test will fail on a vma being torn down, and not grab a page table
         * on its way out.  We're lucky that the flag has such an appropriate
         * name, and can in fact be safely cleared here. We could clear it
         * before the __unmap_hugepage_range above, but all that's necessary
         * is to clear it before releasing the i_mmap_rwsem. This works
         * because in the context this is called, the VMA is about to be
         * destroyed and the i_mmap_rwsem is held.
         */
	vma->vm_flags &= ~VM_MAYSHARE;
}

Contributors
Person Tokens Prop Commits CommitProp
Mel Gorman 48 97.96% 1 50.00%
Davidlohr Bueso A 1 2.04% 1 50.00%
Total 49 100.00% 2 100.00%



void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
			  unsigned long end, struct page *ref_page)
{
	struct mm_struct *mm;
	struct mmu_gather tlb;

	mm = vma->vm_mm;

	tlb_gather_mmu(&tlb, mm, start, end);
	__unmap_hugepage_range(&tlb, vma, start, end, ref_page);
	tlb_finish_mmu(&tlb, start, end);
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 32 43.24% 1 14.29%
Aneesh Kumar K.V 29 39.19% 1 14.29%
David Gibson 6 8.11% 2 28.57%
Linus Torvalds 3 4.05% 1 14.29%
Ken Chen 3 4.05% 1 14.29%
Adam Litke 1 1.35% 1 14.29%
Total 74 100.00% 7 100.00%

/*
 * This is called when the original mapper is failing to COW a MAP_PRIVATE
 * mappping it owns the reserve page for. The intention is to unmap the page
 * from other VMAs and let the children be SIGKILLed if they are faulting the
 * same region.
 */


static void unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
			      struct page *page, unsigned long address)
{
	struct hstate *h = hstate_vma(vma);
	struct vm_area_struct *iter_vma;
	struct address_space *mapping;
	pgoff_t pgoff;

	/*
         * vm_pgoff is in PAGE_SIZE units, hence the different calculation
         * from page cache lookup which is in HPAGE_SIZE units.
         */
	address = address & huge_page_mask(h);
	pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) +
			vma->vm_pgoff;
	mapping = vma->vm_file->f_mapping;

	/*
         * Take the mapping lock for the duration of the table walk. As
         * this mapping should be shared between all the VMAs,
         * __unmap_hugepage_range() is called as the lock is already held
         */
	i_mmap_lock_write(mapping);
	vma_interval_tree_foreach(iter_vma, &mapping->i_mmap, pgoff, pgoff) {
		/* Do not unmap the current VMA */
		if (iter_vma == vma)
			continue;

		/*
                 * Shared VMAs have their own reserves and do not affect
                 * MAP_PRIVATE accounting but it is possible that a shared
                 * VMA is using the same page so check and skip such VMAs.
                 */
		if (iter_vma->vm_flags & VM_MAYSHARE)
			continue;

		/*
                 * Unmap the page from other VMAs without their own reserves.
                 * They get marked to be SIGKILLed if they fault in these
                 * areas. This is because a future no-page fault on this VMA
                 * could insert a zeroed page instead of the data existing
                 * from the time of fork. This would look like data corruption
                 */
		if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER))
			unmap_hugepage_range(iter_vma, address,
					     address + huge_page_size(h), page);
	}
	i_mmap_unlock_write(mapping);
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 67 44.08% 1 5.56%
David Gibson 24 15.79% 3 16.67%
Mel Gorman 21 13.82% 3 16.67%
Adam Litke 16 10.53% 2 11.11%
Michal Hocko 14 9.21% 1 5.56%
Davidlohr Bueso A 3 1.97% 2 11.11%
Gerald Schaefer 2 1.32% 1 5.56%
Al Viro 1 0.66% 1 5.56%
Harvey Harrison 1 0.66% 1 5.56%
Hillf Danton 1 0.66% 1 5.56%
Aneesh Kumar K.V 1 0.66% 1 5.56%
Michel Lespinasse 1 0.66% 1 5.56%
Total 152 100.00% 18 100.00%

/*
 * Hugetlb_cow() should be called with page lock of the original hugepage held.
 * Called with hugetlb_instantiation_mutex held and pte_page locked so we
 * cannot race with other handlers or page migration.
 * Keep the pte_same checks anyway to make transition from the mutex easier.
 */


static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
		       unsigned long address, pte_t *ptep,
		       struct page *pagecache_page, spinlock_t *ptl)
{
	pte_t pte;
	struct hstate *h = hstate_vma(vma);
	struct page *old_page, *new_page;
	int ret = 0, outside_reserve = 0;
	unsigned long mmun_start;	/* For mmu_notifiers */
	unsigned long mmun_end;		/* For mmu_notifiers */

	pte = huge_ptep_get(ptep);
	old_page = pte_page(pte);

retry_avoidcopy:
	/* If no-one else is actually using this page, avoid the copy
         * and just make the page writable */
	if (page_mapcount(old_page) == 1 && PageAnon(old_page)) {
		page_move_anon_rmap(old_page, vma);
		set_huge_ptep_writable(vma, address, ptep);
		return 0;
	}

	/*
         * If the process that created a MAP_PRIVATE mapping is about to
         * perform a COW due to a shared page count, attempt to satisfy
         * the allocation without using the existing reserves. The pagecache
         * page is used to determine if the reserve at this address was
         * consumed or not. If reserves were used, a partial faulted mapping
         * at the time of fork() could consume its reserves on COW instead
         * of the full address range.
         */
	if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) &&
			old_page != pagecache_page)
		outside_reserve = 1;

	get_page(old_page);

	/*
         * Drop page table lock as buddy allocator may be called. It will
         * be acquired again before returning to the caller, as expected.
         */
	spin_unlock(ptl);
	new_page = alloc_huge_page(vma, address, outside_reserve);

	if (IS_ERR(new_page)) {
		/*
                 * If a process owning a MAP_PRIVATE mapping fails to COW,
                 * it is due to references held by a child and an insufficient
                 * huge page pool. To guarantee the original mappers
                 * reliability, unmap the page from child processes. The child
                 * may get SIGKILLed if it later faults.
                 */
		if (outside_reserve) {
			put_page(old_page);
			BUG_ON(huge_pte_none(pte));
			unmap_ref_private(mm, vma, old_page, address);
			BUG_ON(huge_pte_none(pte));
			spin_lock(ptl);
			ptep = huge_pte_offset(mm, address & huge_page_mask(h),
					       huge_page_size(h));
			if (likely(ptep &&
				   pte_same(huge_ptep_get(ptep), pte)))
				goto retry_avoidcopy;
			/*
                         * race occurs while re-acquiring page table
                         * lock, and our job is done.
                         */
			return 0;
		}

		ret = (PTR_ERR(new_page) == -ENOMEM) ?
			VM_FAULT_OOM : VM_FAULT_SIGBUS;
		goto out_release_old;
	}

	/*
         * When the original hugepage is shared one, it does not have
         * anon_vma prepared.
         */
	if (unlikely(anon_vma_prepare(vma))) {
		ret = VM_FAULT_OOM;
		goto out_release_all;
	}

	copy_user_huge_page(new_page, old_page, address, vma,
			    pages_per_huge_page(h));
	__SetPageUptodate(new_page);
	set_page_huge_active(new_page);

	mmun_start = address & huge_page_mask(h);
	mmun_end = mmun_start + huge_page_size(h);
	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);

	/*
         * Retake the page table lock to check for racing updates
         * before the page tables are altered
         */
	spin_lock(ptl);
	ptep = huge_pte_offset(mm, address & huge_page_mask(h),
			       huge_page_size(h));
	if (likely(ptep && pte_same(huge_ptep_get(ptep), pte))) {
		ClearPagePrivate(new_page);

		/* Break COW */
		huge_ptep_clear_flush(vma, address, ptep);
		mmu_notifier_invalidate_range(mm, mmun_start, mmun_end);
		set_huge_pte_at(mm, address, ptep,
				make_huge_pte(vma, new_page, 1));
		page_remove_rmap(old_page, true);
		hugepage_add_new_anon_rmap(new_page, vma, address);
		/* Make the old page be freed below */
		new_page = old_page;
	}
	spin_unlock(ptl);
	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
out_release_all:
	restore_reserve_on_error(h, vma, address, new_page);
	put_page(new_page);
out_release_old:
	put_page(old_page);

	spin_lock(ptl); /* Caller expects lock to be held */
	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 143 28.15% 1 3.23%
Naoya Horiguchi 49 9.65% 5 16.13%
Sagi Grimberg 45 8.86% 1 3.23%
Adam Litke 40 7.87% 1 3.23%
Davidlohr Bueso A 35 6.89% 2 6.45%
David Gibson 34 6.69% 2 6.45%
Hillf Danton 32 6.30% 1 3.23%
Kirill A. Shutemov 16 3.15% 3 9.68%
Mel Gorman 15 2.95% 1 3.23%
Aneesh Kumar K.V 14 2.76% 2 6.45%
Andi Kleen 14 2.76% 1 3.23%
JoonSoo Kim 13 2.56% 3 9.68%
Mike Kravetz 11 2.17% 1 3.23%
Larry Woodman 10 1.97% 1 3.23%
Punit Agrawal 10 1.97% 1 3.23%
Joerg Roedel 9 1.77% 1 3.23%
Doug Doan 6 1.18% 1 3.23%
Gerald Schaefer 5 0.98% 1 3.23%
Andrea Arcangeli 5 0.98% 1 3.23%
Dean Nelson 2 0.39% 1 3.23%
Total 508 100.00% 31 100.00%

/* Return the pagecache page at a given address within a VMA */


static struct page *hugetlbfs_pagecache_page(struct hstate *h,
			struct vm_area_struct *vma, unsigned long address)
{
	struct address_space *mapping;
	pgoff_t idx;

	mapping = vma->vm_file->f_mapping;
	idx = vma_hugecache_offset(h, vma, address);

	return find_lock_page(mapping, idx);
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 41 71.93% 1 16.67%
Andi Kleen 7 12.28% 1 16.67%
David Gibson 6 10.53% 2 33.33%
Adam Litke 2 3.51% 1 16.67%
Johannes Weiner 1 1.75% 1 16.67%
Total 57 100.00% 6 100.00%

/*
 * Return whether there is a pagecache page to back given address within VMA.
 * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page.
 */


static bool hugetlbfs_pagecache_present(struct hstate *h,
			struct vm_area_struct *vma, unsigned long address)
{
	struct address_space *mapping;
	pgoff_t idx;
	struct page *page;

	mapping = vma->vm_file->f_mapping;
	idx = vma_hugecache_offset(h, vma, address);

	page = find_get_page(mapping, idx);
	if (page)
		put_page(page);
	return page != NULL;
}

Contributors
Person Tokens Prop Commits CommitProp
Hugh Dickins 75 100.00% 2 100.00%
Total 75 100.00% 2 100.00%



int huge_add_to_page_cache(struct page *page, struct address_space *mapping,
			   pgoff_t idx)
{
	struct inode *inode = mapping->host;
	struct hstate *h = hstate_inode(inode);
	int err = add_to_page_cache(page, mapping, idx, GFP_KERNEL);

	if (err)
		return err;
	ClearPagePrivate(page);

	spin_lock(&inode->i_lock);
	inode->i_blocks += blocks_per_huge_page(h);
	spin_unlock(&inode->i_lock);
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Kravetz 91 100.00% 1 100.00%
Total 91 100.00% 1 100.00%



static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
			   struct address_space *mapping, pgoff_t idx,
			   unsigned long address, pte_t *ptep, unsigned int flags)
{
	struct hstate *h = hstate_vma(vma);
	int ret = VM_FAULT_SIGBUS;
	int anon_rmap = 0;
	unsigned long size;
	struct page *page;
	pte_t new_pte;
	spinlock_t *ptl;

	/*
         * Currently, we are forced to kill the process in the event the
         * original mapper has unmapped pages from the child due to a failed
         * COW. Warn that such a situation has occurred as it may not be obvious
         */
	if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) {
		pr_warn_ratelimited("PID %d killed due to inadequate hugepage pool\n",
			   current->pid);
		return ret;
	}

	/*
         * Use page lock to guard against racing truncation
         * before we get page_table_lock.
         */
retry:
	page = find_lock_page(mapping, idx);
	if (!page) {
		size = i_size_read(mapping->host) >> huge_page_shift(h);
		if (idx >= size)
			goto out;

		/*
                 * Check for page in userfault range
                 */
		if (userfaultfd_missing(vma)) {
			u32 hash;
			struct vm_fault vmf = {
				.vma = vma,
				.address = address,
				.flags = flags,
				/*
                                 * Hard to debug if it ends up being
                                 * used by a callee that assumes
                                 * something about the other
                                 * uninitialized fields... same as in
                                 * memory.c
                                 */
			};

			/*
                         * hugetlb_fault_mutex must be dropped before
                         * handling userfault.  Reacquire after handling
                         * fault to make calling code simpler.
                         */
			hash = hugetlb_fault_mutex_hash(h, mm, vma, mapping,
							idx, address);
			mutex_unlock(&hugetlb_fault_mutex_table[hash]);
			ret = handle_userfault(&vmf, VM_UFFD_MISSING);
			mutex_lock(&hugetlb_fault_mutex_table[hash]);
			goto out;
		}

		page = alloc_huge_page(vma, address, 0);
		if (IS_ERR(page)) {
			ret = PTR_ERR(page);
			if (ret == -ENOMEM)
				ret = VM_FAULT_OOM;
			else
				ret = VM_FAULT_SIGBUS;
			goto out;
		}
		clear_huge_page(page, address, pages_per_huge_page(h));
		__SetPageUptodate(page);
		set_page_huge_active(page);

		if (vma->vm_flags & VM_MAYSHARE) {
			int err = huge_add_to_page_cache(page, mapping, idx);
			if (err) {
				put_page(page);
				if (err == -EEXIST)
					goto retry;
				goto out;
			}
		} else {
			lock_page(page);
			if (unlikely(anon_vma_prepare(vma))) {
				ret = VM_FAULT_OOM;
				goto backout_unlocked;
			}
			anon_rmap = 1;
		}
	} else {
		/*
                 * If memory error occurs between mmap() and fault, some process
                 * don't have hwpoisoned swap entry for errored virtual address.
                 * So we need to block hugepage fault by PG_hwpoison bit check.
                 */
		if (unlikely(PageHWPoison(page))) {
			ret = VM_FAULT_HWPOISON |
				VM_FAULT_SET_HINDEX(hstate_index(h));
			goto backout_unlocked;
		}
	}

	/*
         * If we are going to COW a private mapping later, we examine the
         * pending reservations for this page now. This will ensure that
         * any allocations necessary to record that reservation occur outside
         * the spinlock.
         */
	if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) {
		if (vma_needs_reservation(h, vma, address) < 0) {
			ret = VM_FAULT_OOM;
			goto backout_unlocked;
		}
		/* Just decrements count, does not deallocate */
		vma_end_reservation(h, vma, address);
	}

	ptl = huge_pte_lock(h, mm, ptep);
	size = i_size_read(mapping->host) >> huge_page_shift(h);
	if (idx >= size)
		goto backout;

	ret = 0;
	if (!huge_pte_none(huge_ptep_get(ptep)))
		goto backout;

	if (anon_rmap) {
		ClearPagePrivate(page);
		hugepage_add_new_anon_rmap(page, vma, address);
	} else
		page_dup_rmap(page, true);
	new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE)
				&& (vma->vm_flags & VM_SHARED)));
	set_huge_pte_at(mm, address, ptep, new_pte);

	hugetlb_count_add(pages_per_huge_page(h), mm);
	if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) {
		/* Optimization, do the COW without a second fault */
		ret = hugetlb_cow(mm, vma, address, ptep, page, ptl);
	}

	spin_unlock(ptl);
	unlock_page(page);
out:
	return ret;

backout:
	spin_unlock(ptl);
backout_unlocked:
	unlock_page(page);
	restore_reserve_on_error(h, vma, address, page);
	put_page(page);
	goto out;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 243 36.60% 3 7.89%
Mike Kravetz 110 16.57% 5 13.16%
Naoya Horiguchi 54 8.13% 5 13.16%
Yanmin Zhang 48 7.23% 1 2.63%
David Gibson 37 5.57% 1 2.63%
Andi Kleen 27 4.07% 2 5.26%
Hillf Danton 27 4.07% 1 2.63%
Kenneth W. Chen 21 3.16% 3 7.89%
Aneesh Kumar K.V 20 3.01% 3 7.89%
Hugh Dickins 19 2.86% 2 5.26%
Kirill A. Shutemov 18 2.71% 2 5.26%
Davidlohr Bueso A 8 1.20% 1 2.63%
Gerald Schaefer 8 1.20% 1 2.63%
Adam Litke 7 1.05% 2 5.26%
Mel Gorman 7 1.05% 2 5.26%
JoonSoo Kim 7 1.05% 1 2.63%
Lucas De Marchi 1 0.15% 1 2.63%
Geoffrey Thomas 1 0.15% 1 2.63%
Andrea Arcangeli 1 0.15% 1 2.63%
Total 664 100.00% 38 100.00%

#ifdef CONFIG_SMP


u32 hugetlb_fault_mutex_hash(struct hstate *h, struct mm_struct *mm,
			    struct vm_area_struct *vma,
			    struct address_space *mapping,
			    pgoff_t idx, unsigned long address)
{
	unsigned long key[2];
	u32 hash;

	if (vma->vm_flags & VM_SHARED) {
		key[0] = (unsigned long) mapping;
		key[1] = idx;
	} else {
		key[0] = (unsigned long) mm;
		key[1] = address >> huge_page_shift(h);
	}

	hash = jhash2((u32 *)&key, sizeof(key)/sizeof(u32), 0);

	return hash & (num_fault_mutexes - 1);
}
Contributors
Person Tokens Prop Commits CommitProp
Davidlohr Bueso A 128 99.22% 1 50.00%
Mike Kravetz 1 0.78% 1 50.00%
Total 129 100.00% 2 100.00%

#else
/*
 * For uniprocesor systems we always use a single mutex, so just
 * return 0 and avoid the hashing overhead.
 */


u32 hugetlb_fault_mutex_hash(struct hstate *h, struct mm_struct *mm,
			    struct vm_area_struct *vma,
			    struct address_space *mapping,
			    pgoff_t idx, unsigned long address)
{
	return 0;
}
Contributors
Person Tokens Prop Commits CommitProp
Davidlohr Bueso A 34 97.14% 1 50.00%
Mike Kravetz 1 2.86% 1 50.00%
Total 35 100.00% 2 100.00%

#endif



int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
			unsigned long address, unsigned int flags)
{
	pte_t *ptep, entry;
	spinlock_t *ptl;
	int ret;
	u32 hash;
	pgoff_t idx;
	struct page *page = NULL;
	struct page *pagecache_page = NULL;
	struct hstate *h = hstate_vma(vma);
	struct address_space *mapping;
	int need_wait_lock = 0;

	address &= huge_page_mask(h);

	ptep = huge_pte_offset(mm, address, huge_page_size(h));
	if (ptep) {
		entry = huge_ptep_get(ptep);
		if (unlikely(is_hugetlb_entry_migration(entry))) {
			migration_entry_wait_huge(vma, mm, ptep);
			return 0;
		} else if (unlikely(is_hugetlb_entry_hwpoisoned(entry)))
			return VM_FAULT_HWPOISON_LARGE |
				VM_FAULT_SET_HINDEX(hstate_index(h));
	} else {
		ptep = huge_pte_alloc(mm, address, huge_page_size(h));
		if (!ptep)
			return VM_FAULT_OOM;
	}

	mapping = vma->vm_file->f_mapping;
	idx = vma_hugecache_offset(h, vma, address);

	/*
         * Serialize hugepage allocation and instantiation, so that we don't
         * get spurious allocation failures if two CPUs race to instantiate
         * the same page in the page cache.
         */
	hash = hugetlb_fault_mutex_hash(h, mm, vma, mapping, idx, address);
	mutex_lock(&hugetlb_fault_mutex_table[hash]);

	entry = huge_ptep_get(ptep);
	if (huge_pte_none(entry)) {
		ret = hugetlb_no_page(mm, vma, mapping, idx, address, ptep, flags);
		goto out_mutex;
	}

	ret = 0;

	/*
         * entry could be a migration/hwpoison entry at this point, so this
         * check prevents the kernel from going below assuming that we have
         * a active hugepage in pagecache. This goto expects the 2nd page fault,
         * and is_hugetlb_entry_(migration|hwpoisoned) check will properly
         * handle it.
         */
	if (!pte_present(entry))
		goto out_mutex;

	/*
         * If we are going to COW the mapping later, we examine the pending
         * reservations for this page now. This will ensure that any
         * allocations necessary to record that reservation occur outside the
         * spinlock. For private mappings, we also lookup the pagecache
         * page now as it is used to determine if a reservation has been
         * consumed.
         */
	if ((flags & FAULT_FLAG_WRITE) && !huge_pte_write(entry)) {
		if (vma_needs_reservation(h, vma, address) < 0) {
			ret = VM_FAULT_OOM;
			goto out_mutex;
		}
		/* Just decrements count, does not deallocate */
		vma_end_reservation(h, vma, address);

		if (!(vma->vm_flags & VM_MAYSHARE))
			pagecache_page = hugetlbfs_pagecache_page(h,
								vma, address);
	}

	ptl = huge_pte_lock(h, mm, ptep);

	/* Check for a racing update before calling hugetlb_cow */
	if (unlikely(!pte_same(entry, huge_ptep_get(ptep))))
		goto out_ptl;

	/*
         * hugetlb_cow() requires page locks of pte_page(entry) and
         * pagecache_page, so here we need take the former one
         * when page != pagecache_page or !pagecache_page.
         */
	page = pte_page(entry);
	if (page != pagecache_page)
		if (!trylock_page(page)) {
			need_wait_lock = 1;
			goto out_ptl;
		}

	get_page(page);

	if (flags & FAULT_FLAG_WRITE) {
		if (!huge_pte_write(entry)) {
			ret = hugetlb_cow(mm, vma, address, ptep,
					  pagecache_page, ptl);
			goto out_put_page;
		}
		entry = huge_pte_mkdirty(entry);
	}
	entry = pte_mkyoung(entry);
	if (huge_ptep_set_access_flags(vma, address, ptep, entry,
						flags & FAULT_FLAG_WRITE))
		update_mmu_cache(vma, address, ptep);
out_put_page:
	if (page != pagecache_page)
		unlock_page(page);
	put_page(page);
out_ptl:
	spin_unlock(ptl);

	if (pagecache_page) {
		unlock_page(pagecache_page);
		put_page(pagecache_page);
	}
out_mutex:
	mutex_unlock(&hugetlb_fault_mutex_table[hash]);
	/*
         * Generally it's safe to hold refcount during waiting page lock. But
         * here we just wait to defer the next page fault to avoid busy loop and
         * the page is not used after unlocked before returning from the current
         * page fault. So we are safe from accessing freed page, even if we wait
         * here without taking refcount.
         */
	if (need_wait_lock)
		wait_on_page_locked(page);
	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 173 30.78% 3 11.11%
Naoya Horiguchi 152 27.05% 6 22.22%
Davidlohr Bueso A 57 10.14% 1 3.70%
David Gibson 52 9.25% 1 3.70%
Kenneth W. Chen 35 6.23% 1 3.70%
Andi Kleen 21 3.74% 2 7.41%
Kirill A. Shutemov 17 3.02% 1 3.70%
Hugh Dickins 14 2.49% 1 3.70%
Mike Kravetz 13 2.31% 3 11.11%
Kamezawa Hiroyuki 7 1.25% 1 3.70%
Punit Agrawal 5 0.89% 1 3.70%
Chris Metcalf 4 0.71% 1 3.70%
Dean Nelson 4 0.71% 1 3.70%
Aneesh Kumar K.V 3 0.53% 1 3.70%
Gerald Schaefer 3 0.53% 1 3.70%
Mel Gorman 1 0.18% 1 3.70%
Russell King 1 0.18% 1 3.70%
Total 562 100.00% 27 100.00%

/*
 * Used by userfaultfd UFFDIO_COPY.  Based on mcopy_atomic_pte with
 * modifications for huge pages.
 */


int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
			    pte_t *dst_pte,
			    struct vm_area_struct *dst_vma,
			    unsigned long dst_addr,
			    unsigned long src_addr,
			    struct page **pagep)
{
	int vm_shared = dst_vma->vm_flags & VM_SHARED;
	struct hstate *h = hstate_vma(dst_vma);
	pte_t _dst_pte;
	spinlock_t *ptl;
	int ret;
	struct page *page;

	if (!*pagep) {
		ret = -ENOMEM;
		page = alloc_huge_page(dst_vma, dst_addr, 0);
		if (IS_ERR(page))
			goto out;

		ret = copy_huge_page_from_user(page,
						(const void __user *) src_addr,
						pages_per_huge_page(h), false);

		/* fallback to copy_from_user outside mmap_sem */
		if (unlikely(ret)) {
			ret = -EFAULT;
			*pagep = page;
			/* don't free the page */
			goto out;
		}
	} else {
		page = *pagep;
		*pagep = NULL;
	}

	/*
         * The memory barrier inside __SetPageUptodate makes sure that
         * preceding stores to the page contents become visible before
         * the set_pte_at() write.
         */
	__SetPageUptodate(page);
	set_page_huge_active(page);

	/*
         * If shared, add to page cache
         */
	if (vm_shared) {
		struct address_space *mapping = dst_vma->vm_file->f_mapping;
		pgoff_t idx = vma_hugecache_offset(h, dst_vma, dst_addr);

		ret = huge_add_to_page_cache(page, mapping, idx);
		if (ret)
			goto out_release_nounlock;
	}

	ptl = huge_pte_lockptr(h, dst_mm, dst_pte);
	spin_lock(ptl);

	ret = -EEXIST;
	if (!huge_pte_none(huge_ptep_get(dst_pte)))
		goto out_release_unlock;

	if (vm_shared) {
		page_dup_rmap(page, true);
	} else {
		ClearPagePrivate(page);
		hugepage_add_new_anon_rmap(page, dst_vma, dst_addr);
	}

	_dst_pte = make_huge_pte(dst_vma, page, dst_vma->vm_flags & VM_WRITE);
	if (dst_vma->vm_flags & VM_WRITE)
		_dst_pte = huge_pte_mkdirty(_dst_pte);
	_dst_pte = pte_mkyoung(_dst_pte);

	set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);

	(void)huge_ptep_set_access_flags(dst_vma, dst_addr, dst_pte, _dst_pte,
					dst_vma->vm_flags & VM_WRITE);
	hugetlb_count_add(pages_per_huge_page(h), dst_mm);

	/* No need to invalidate - it was non-present before */
	update_mmu_cache(dst_vma, dst_addr, dst_pte);

	spin_unlock(ptl);
	if (vm_shared)
		unlock_page(page);
	ret = 0;
out:
	return ret;
out_release_unlock:
	spin_unlock(ptl);
	if (vm_shared)
		unlock_page(page);
out_release_nounlock:
	put_page(page);
	goto out;
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Kravetz 419 99.52% 3 75.00%
Andrea Arcangeli 2 0.48% 1 25.00%
Total 421 100.00% 4 100.00%



long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
			 struct page **pages, struct vm_area_struct **vmas,
			 unsigned long *position, unsigned long *nr_pages,
			 long i, unsigned int flags, int *nonblocking)
{
	unsigned long pfn_offset;
	unsigned long vaddr = *position;
	unsigned long remainder = *nr_pages;
	struct hstate *h = hstate_vma(vma);
	int err = -EFAULT;

	while (vaddr < vma->vm_end && remainder) {
		pte_t *pte;
		spinlock_t *ptl = NULL;
		int absent;
		struct page *page;

		/*
                 * If we have a pending SIGKILL, don't keep faulting pages and
                 * potentially allocating memory.
                 */
		if (unlikely(fatal_signal_pending(current))) {
			remainder = 0;
			break;
		}

		/*
                 * Some archs (sparc64, sh*) have multiple pte_ts to
                 * each hugepage.  We have to make sure we get the
                 * first, for the page indexing below to work.
                 *
                 * Note that page table lock is not held when pte is null.
                 */
		pte = huge_pte_offset(mm, vaddr & huge_page_mask(h),
				      huge_page_size(h));
		if (pte)
			ptl = huge_pte_lock(h, mm, pte);
		absent = !pte || huge_pte_none(huge_ptep_get(pte));

		/*
                 * When coredumping, it suits get_dump_page if we just return
                 * an error where there's an empty slot with no huge pagecache
                 * to back it.  This way, we avoid allocating a hugepage, and
                 * the sparse dumpfile avoids allocating disk blocks, but its
                 * huge holes still show up with zeroes where they need to be.
                 */
		if (absent && (flags & FOLL_DUMP) &&
		    !hugetlbfs_pagecache_present(h, vma, vaddr)) {
			if (pte)
				spin_unlock(ptl);
			remainder = 0;
			break;
		}

		/*
                 * We need call hugetlb_fault for both hugepages under migration
                 * (in which case hugetlb_fault waits for the migration,) and
                 * hwpoisoned hugepages (in which case we need to prevent the
                 * caller from accessing to them.) In order to do this, we use
                 * here is_swap_pte instead of is_hugetlb_entry_migration and
                 * is_hugetlb_entry_hwpoisoned. This is because it simply covers
                 * both cases, and because we can't follow correct pages
                 * directly from any kind of swap entries.
                 */
		if (absent || is_swap_pte(huge_ptep_get(pte)) ||
		    ((flags & FOLL_WRITE) &&
		      !huge_pte_write(huge_ptep_get(pte)))) {
			int ret;
			unsigned int fault_flags = 0;

			if (pte)
				spin_unlock(ptl);
			if (flags & FOLL_WRITE)
				fault_flags |= FAULT_FLAG_WRITE;
			if (nonblocking)
				fault_flags |= FAULT_FLAG_ALLOW_RETRY;
			if (flags & FOLL_NOWAIT)
				fault_flags |= FAULT_FLAG_ALLOW_RETRY |
					FAULT_FLAG_RETRY_NOWAIT;
			if (flags & FOLL_TRIED) {
				VM_WARN_ON_ONCE(fault_flags &
						FAULT_FLAG_ALLOW_RETRY);
				fault_flags |= FAULT_FLAG_TRIED;
			}
			ret = hugetlb_fault(mm, vma, vaddr, fault_flags);
			if (ret & VM_FAULT_ERROR) {
				err = vm_fault_to_errno(ret, flags);
				remainder = 0;
				break;
			}
			if (ret & VM_FAULT_RETRY) {
				if (nonblocking)
					*nonblocking = 0;
				*nr_pages = 0;
				/*
                                 * VM_FAULT_RETRY must not return an
                                 * error, it will return zero
                                 * instead.
                                 *
                                 * No need to update "position" as the
                                 * caller will not check it after
                                 * *nr_pages is set to 0.
                                 */
				return i;
			}
			continue;
		}

		pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT;
		page = pte_page(huge_ptep_get(pte));
same_page:
		if (pages) {
			pages[i] = mem_map_offset(page, pfn_offset);
			get_page(pages[i]);
		}

		if (vmas)
			vmas[i] = vma;

		vaddr += PAGE_SIZE;
		++pfn_offset;
		--remainder;
		++i;
		if (vaddr < vma->vm_end && remainder &&
				pfn_offset < pages_per_huge_page(h)) {
			/*
                         * We use pfn_offset to avoid touching the pageframes
                         * of this compound page.
                         */
			goto same_page;
		}
		spin_unlock(ptl);
	}
	*nr_pages = remainder;
	/*
         * setting position is actually required only if remainder is
         * not zero but it's faster not to add a "if (remainder)"
         * branch.
         */
	*position = vaddr;

	return i ? i : err;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 184 36.95% 2 11.11%
Andrea Arcangeli 90 18.07% 1 5.56%
Kenneth W. Chen 50 10.04% 1 5.56%
Hugh Dickins 44 8.84% 2 11.11%
Kirill A. Shutemov 39 7.83% 2 11.11%
Andi Kleen 22 4.42% 1 5.56%
David Rientjes 18 3.61% 1 5.56%
Motohiro Kosaki 10 2.01% 1 5.56%
Michel Lespinasse 9 1.81% 1 5.56%
Naoya Horiguchi 9 1.81% 1 5.56%
Daniel Jordan 9 1.81% 1 5.56%
James Morse 7 1.41% 1 5.56%
Punit Agrawal 5 1.00% 1 5.56%
Stephen Hemminger 1 0.20% 1 5.56%
Gerald Schaefer 1 0.20% 1 5.56%
Total 498 100.00% 18 100.00%

#ifndef __HAVE_ARCH_FLUSH_HUGETLB_TLB_RANGE
/*
 * ARCHes with special requirements for evicting HUGETLB backing TLB entries can
 * implement this.
 */

#define flush_hugetlb_tlb_range(vma, addr, end)	flush_tlb_range(vma, addr, end)
#endif



unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
		unsigned long address, unsigned long end, pgprot_t newprot)
{
	struct mm_struct *mm = vma->vm_mm;
	unsigned long start = address;
	pte_t *ptep;
	pte_t pte;
	struct hstate *h = hstate_vma(vma);
	unsigned long pages = 0;

	BUG_ON(address >= end);
	flush_cache_range(vma, address, end);

	mmu_notifier_invalidate_range_start(mm, start, end);
	i_mmap_lock_write(vma->vm_file->f_mapping);
	for (; address < end; address += huge_page_size(h)) {
		spinlock_t *ptl;
		ptep = huge_pte_offset(mm, address, huge_page_size(h));
		if (!ptep)
			continue;
		ptl = huge_pte_lock(h, mm, ptep);
		if (huge_pmd_unshare(mm, &address, ptep)) {
			pages++;
			spin_unlock(ptl);
			continue;
		}
		pte = huge_ptep_get(ptep);
		if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) {
			spin_unlock(ptl);
			continue;
		}
		if (unlikely(is_hugetlb_entry_migration(pte))) {
			swp_entry_t entry = pte_to_swp_entry(pte);

			if (is_write_migration_entry(entry)) {
				pte_t newpte;

				make_migration_entry_read(&entry);
				newpte = swp_entry_to_pte(entry);
				set_huge_swap_pte_at(mm, address, ptep,
						     newpte, huge_page_size(h));
				pages++;
			}
			spin_unlock(ptl);
			continue;
		}
		if (!huge_pte_none(pte)) {
			pte = huge_ptep_get_and_clear(mm, address, ptep);
			pte = pte_mkhuge(huge_pte_modify(pte, newprot));
			pte = arch_make_huge_pte(pte, vma, NULL, 0);
			set_huge_pte_at(mm, address, ptep, pte);
			pages++;
		}
		spin_unlock(ptl);
	}
	/*
         * Must flush TLB before releasing i_mmap_rwsem: x86's huge_pmd_unshare
         * may have cleared our pud entry and done put_page on the page table:
         * once we release i_mmap_rwsem, another task can do the final put_page
         * and that page table be reused and filled with junk.
         */
	flush_hugetlb_tlb_range(vma, start, end);
	mmu_notifier_invalidate_range(mm, start, end);
	i_mmap_unlock_write(vma->vm_file->f_mapping);
	mmu_notifier_invalidate_range_end(mm, start, end);

	return pages << h->order;
}

Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 112 30.11% 1 6.25%
Naoya Horiguchi 89 23.92% 1 6.25%
Kenneth W. Chen 48 12.90% 1 6.25%
Peter Zijlstra 23 6.18% 1 6.25%
Kirill A. Shutemov 22 5.91% 1 6.25%
Rik Van Riel 18 4.84% 1 6.25%
Andi Kleen 14 3.76% 1 6.25%
Mel Gorman 13 3.49% 1 6.25%
Tony Lu 13 3.49% 1 6.25%
Punit Agrawal 11 2.96% 2 12.50%
Joerg Roedel 4 1.08% 1 6.25%
Davidlohr Bueso A 3 0.81% 2 12.50%
Aneesh Kumar K.V 1 0.27% 1 6.25%
Gerald Schaefer 1 0.27% 1 6.25%
Total 372 100.00% 16 100.00%



int hugetlb_reserve_pages(struct inode *inode,
					long from, long to,
					struct vm_area_struct *vma,
					vm_flags_t vm_flags)
{
	long ret, chg;
	struct hstate *h = hstate_inode(inode);
	struct hugepage_subpool *spool = subpool_inode(inode);
	struct resv_map *resv_map;
	long gbl_reserve;

	/*
         * Only apply hugepage reservation if asked. At fault time, an
         * attempt will be made for VM_NORESERVE to allocate a page
         * without using reserves
         */
	if (vm_flags & VM_NORESERVE)
		return 0;

	/*
         * Shared mappings base their reservation on the number of pages that
         * are already allocated on behalf of the file. Private mappings need
         * to reserve the full area even if read-only as mprotect() may be
         * called to make the mapping read-write. Assume !vma is a shm mapping
         */
	if (!vma || vma->vm_flags & VM_MAYSHARE) {
		resv_map = inode_resv_map(inode);

		chg = region_chg(resv_map, from, to);

	} else {
		resv_map = resv_map_alloc();
		if (!resv_map)
			return -ENOMEM;

		chg = to - from;

		set_vma_resv_map(vma, resv_map);
		set_vma_resv_flags(vma, HPAGE_RESV_OWNER);
	}

	if (chg < 0) {
		ret = chg;
		goto out_err;
	}

	/*
         * There must be enough pages in the subpool for the mapping. If
         * the subpool has a minimum size, there may be some global
         * reservations already in place (gbl_reserve).
         */
	gbl_reserve = hugepage_subpool_get_pages(spool, chg);
	if (gbl_reserve < 0) {
		ret = -ENOSPC;
		goto out_err;
	}

	/*
         * Check enough hugepages are available for the reservation.
         * Hand the pages back to the subpool if there are not
         */
	ret = hugetlb_acct_memory(h, gbl_reserve);
	if (ret < 0) {
		/* put back original number of pages, chg */
		(void)hugepage_subpool_put_pages(spool, chg);
		goto out_err;
	}

	/*
         * Account for the reservations made. Shared mappings record regions
         * that have reservations as they are shared by multiple VMAs.
         * When the last VMA disappears, the region map says how much
         * the reservation was and the page cache tells how much of
         * the reservation was consumed. Private mappings are per-VMA and
         * only the consumed reservations are tracked. When the VMA
         * disappears, the original reservation is the VMA size and the
         * consumed reservations are stored in the map. Hence, nothing
         * else has to be done for private mappings here
         */
	if (!vma || vma->vm_flags & VM_MAYSHARE) {
		long add = region_add(resv_map, from, to);

		if (unlikely(chg > add)) {
			/*
                         * pages in this range were added to the reserve
                         * map between region_chg and region_add.  This
                         * indicates a race with alloc_huge_page.  Adjust
                         * the subpool and reserve counts modified above
                         * based on the difference.
                         */
			long rsv_adjust;

			rsv_adjust = hugepage_subpool_put_pages(spool,
								chg - add);
			hugetlb_acct_memory(h, -rsv_adjust);
		}
	}
	return 0;
out_err:
	if (!vma || vma->vm_flags & VM_MAYSHARE)
		/* Don't call region_abort if region_chg failed */
		if (chg >= 0)
			region_abort(resv_map, from, to);
	if (vma && is_vma_resv_set(vma, HPAGE_RESV_OWNER))
		kref_put(&resv_map->refs, resv_map_release);
	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Kravetz 83 25.54% 4 21.05%
Mel Gorman 73 22.46% 4 21.05%
Kenneth W. Chen 61 18.77% 1 5.26%
JoonSoo Kim 32 9.85% 3 15.79%
Dave Hansen 31 9.54% 2 10.53%
David Gibson 16 4.92% 1 5.26%
Andi Kleen 12 3.69% 1 5.26%
Ken Chen 7 2.15% 1 5.26%
Adam Litke 7 2.15% 1 5.26%
Motohiro Kosaki 3 0.92% 1 5.26%
Total 325 100.00% 19 100.00%



long hugetlb_unreserve_pages(struct inode *inode, long start, long end,
								long freed)
{
	struct hstate *h = hstate_inode(inode);
	struct resv_map *resv_map = inode_resv_map(inode);
	long chg = 0;
	struct hugepage_subpool *spool = subpool_inode(inode);
	long gbl_reserve;

	if (resv_map) {
		chg = region_del(resv_map, start, end);
		/*
                 * region_del() can fail in the rare case where a region
                 * must be split and another region descriptor can not be
                 * allocated.  If end == LONG_MAX, it will not fail.
                 */
		if (chg < 0)
			return chg;
	}

	spin_lock(&inode->i_lock);
	inode->i_blocks -= (blocks_per_huge_page(h) * freed);
	spin_unlock(&inode->i_lock);

	/*
         * If the subpool has a minimum size, the number of global
         * reservations to be released may be adjusted.
         */
	gbl_reserve = hugepage_subpool_put_pages(spool, (chg - freed));
	hugetlb_acct_memory(h, -gbl_reserve);

	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Mike Kravetz 31 22.46% 3 27.27%
JoonSoo Kim 23 16.67% 2 18.18%
Kenneth W. Chen 22 15.94% 1 9.09%
Ken Chen 21 15.22% 1 9.09%
Andi Kleen 16 11.59% 1 9.09%
David Gibson 12 8.70% 1 9.09%
Adam Litke 9 6.52% 1 9.09%
Eric Sandeen 4 2.90% 1 9.09%
Total 138 100.00% 11 100.00%

#ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE


static unsigned long page_table_shareable(struct vm_area_struct *svma,
				struct vm_area_struct *vma,
				unsigned long addr, pgoff_t idx)
{
	unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) +
				svma->vm_start;
	unsigned long sbase = saddr & PUD_MASK;
	unsigned long s_end = sbase + PUD_SIZE;

	/* Allow segments to share if only one is marked locked */
	unsigned long vm_flags = vma->vm_flags & VM_LOCKED_CLEAR_MASK;
	unsigned long svm_flags = svma->vm_flags & VM_LOCKED_CLEAR_MASK;

	/*
         * match the virtual addresses, permission and the alignment of the
         * page table page.
         */
	if (pmd_index(addr) != pmd_index(saddr) ||
	    vm_flags != svm_flags ||
	    sbase < svma->vm_start || svma->vm_end < s_end)
		return 0;

	return saddr;
}

Contributors
Person Tokens Prop Commits CommitProp
Steve Capper 114 98.28% 1 50.00%
Eric B Munson 2 1.72% 1 50.00%
Total 116 100.00% 2 100.00%



static bool vma_shareable(struct vm_area_struct *vma, unsigned long addr)
{
	unsigned long base = addr & PUD_MASK;
	unsigned long end = base + PUD_SIZE;

	/*
         * check on proper vm_flags and page table alignment
         */
	if (vma->vm_flags & VM_MAYSHARE &&
	    vma->vm_start <= base && end <= vma->vm_end)
		return true;
	return false;
}

Contributors
Person Tokens Prop Commits CommitProp
Steve Capper 55 94.83% 1 50.00%
Nicholas Krause 3 5.17% 1 50.00%
Total 58 100.00% 2 100.00%

/*
 * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc()
 * and returns the corresponding pte. While this is not necessary for the
 * !shared pmd case because we can allocate the pmd later as well, it makes the
 * code much cleaner. pmd allocation is essential for the shared case because
 * pud has to be populated inside the same i_mmap_rwsem section - otherwise
 * racing tasks could either miss the sharing (see huge_pte_offset) or select a
 * bad pmd for sharing.
 */


pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
{
	struct vm_area_struct *vma = find_vma(mm, addr);
	struct address_space *mapping = vma->vm_file->f_mapping;
	pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) +
			vma->vm_pgoff;
	struct vm_area_struct *svma;
	unsigned long saddr;
	pte_t *spte = NULL;
	pte_t *pte;
	spinlock_t *ptl;

	if (!vma_shareable(vma, addr))
		return (pte_t *)pmd_alloc(mm, pud, addr);

	i_mmap_lock_write(mapping);
	vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) {
		if (svma == vma)
			continue;

		saddr = page_table_shareable(svma, vma, addr, idx);
		if (saddr) {
			spte = huge_pte_offset(svma->vm_mm, saddr,
					       vma_mmu_pagesize(svma));
			if (spte) {
				get_page(virt_to_page(spte));
				break;
			}
		}
	}

	if (!spte)
		goto out;

	ptl = huge_pte_lock(hstate_vma(vma), mm, spte);
	if (pud_none(*pud)) {
		pud_populate(mm, pud,
				(pmd_t *)((unsigned long)spte & PAGE_MASK));
		mm_inc_nr_pmds(mm);
	} else {
		put_page(virt_to_page(spte));
	}
	spin_unlock(ptl);
out:
	pte = (pte_t *)pmd_alloc(mm, pud, addr);
	i_mmap_unlock_write(mapping);
	return pte;
}

Contributors
Person Tokens Prop Commits CommitProp
Steve Capper 248 88.26% 1 14.29%
Kirill A. Shutemov 25 8.90% 3 42.86%
Punit Agrawal 5 1.78% 1 14.29%
Davidlohr Bueso A 2 0.71% 1 14.29%
Aneesh Kumar K.V 1 0.36% 1 14.29%
Total 281 100.00% 7 100.00%

/*
 * unmap huge page backed by shared pte.
 *
 * Hugetlb pte page is ref counted at the time of mapping.  If pte is shared
 * indicated by page_count > 1, unmap is achieved by clearing pud and
 * decrementing the ref count. If count == 1, the pte page is not shared.
 *
 * called with page table lock held.
 *
 * returns: 1 successfully unmapped a shared pte page
 *          0 the underlying pte page is not shared, or it is the last user
 */


int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
{
	pgd_t *pgd = pgd_offset(mm, *addr);
	p4d_t *p4d = p4d_offset(pgd, *addr);
	pud_t *pud = pud_offset(p4d, *addr);

	BUG_ON(page_count(virt_to_page(ptep)) == 0);
	if (page_count(virt_to_page(ptep)) == 1)
		return 0;

	pud_clear(pud);
	put_page(virt_to_page(ptep));
	mm_dec_nr_pmds(mm);
	*addr = ALIGN(*addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE;
	return 1;
}
Contributors
Person Tokens Prop Commits CommitProp
Steve Capper 101 84.87% 1 33.33%
Kirill A. Shutemov 18 15.13% 2 66.67%
Total 119 100.00% 3 100.00%


#define want_pmd_share()	(1)
#else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */


pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
{
	return NULL;
}

Contributors
Person Tokens Prop Commits CommitProp
Steve Capper 22 100.00% 1 100.00%
Total 22 100.00% 1 100.00%



int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
{
	return 0;
}
Contributors
Person Tokens Prop Commits CommitProp
Zhang Zhen 22 100.00% 1 100.00%
Total 22 100.00% 1 100.00%


#define want_pmd_share()	(0)
#endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */

#ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB


pte_t *huge_pte_alloc(struct mm_struct *mm,
			unsigned long addr, unsigned long sz)
{
	pgd_t *pgd;
	p4d_t *p4d;
	pud_t *pud;
	pte_t *pte = NULL;

	pgd = pgd_offset(mm, addr);
	p4d = p4d_offset(pgd, addr);
	pud = pud_alloc(mm, p4d, addr);
	if (pud) {
		if (sz == PUD_SIZE) {
			pte = (pte_t *)pud;
		} else {
			BUG_ON(sz != PMD_SIZE);
			if (want_pmd_share() && pud_none(*pud))
				pte = huge_pmd_share(mm, addr, pud);
			else
				pte = (pte_t *)pmd_alloc(mm, pud, addr);
		}
	}
	BUG_ON(pte && pte_present(*pte) && !pte_huge(*pte));

	return pte;
}

Contributors
Person Tokens Prop Commits CommitProp
Steve Capper 142 90.45% 1 33.33%
Kirill A. Shutemov 14 8.92% 1 33.33%
Michal Hocko 1 0.64% 1 33.33%
Total 157 100.00% 3 100.00%



pte_t *huge_pte_offset(struct mm_struct *mm,
		       unsigned long addr, unsigned long sz)
{
	pgd_t *pgd;
	p4d_t *p4d;
	pud_t *pud;
	pmd_t *pmd;

	pgd = pgd_offset(mm, addr);
	if (!pgd_present(*pgd))
		return NULL;
	p4d = p4d_offset(pgd, addr);
	if (!p4d_present(*p4d))
		return NULL;
	pud = pud_offset(p4d, addr);
	if (!pud_present(*pud))
		return NULL;
	if (pud_huge(*pud))
		return (pte_t *)pud;
	pmd = pmd_offset(pud, addr);
	return (pte_t *) pmd;
}

Contributors
Person Tokens Prop Commits CommitProp
Steve Capper 91 70.54% 1 33.33%
Kirill A. Shutemov 34 26.36% 1 33.33%
Punit Agrawal 4 3.10% 1 33.33%
Total 129 100.00% 3 100.00%

#endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */

/*
 * These functions are overwritable if your architecture needs its own
 * behavior.
 */

struct page * __weak

follow_huge_addr(struct mm_struct *mm, unsigned long address,
			      int write)
{
	return ERR_PTR(-EINVAL);
}

Contributors
Person Tokens Prop Commits CommitProp
Naoya Horiguchi 24 88.89% 1 50.00%
Steve Capper 3 11.11% 1 50.00%
Total 27 100.00% 2 100.00%


struct page * __weak

follow_huge_pd(struct vm_area_struct *vma,
	       unsigned long address, hugepd_t hpd, int flags, int pdshift)
{
	WARN(1, "hugepd follow called with no support for hugepage directory format\n");
	return NULL;
}

Contributors
Person Tokens Prop Commits CommitProp
Aneesh Kumar K.V 32 88.89% 1 50.00%
Naoya Horiguchi 4 11.11% 1 50.00%
Total 36 100.00% 2 100.00%


struct page * __weak

follow_huge_pmd(struct mm_struct *mm, unsigned long address,
		pmd_t *pmd, int flags)
{
	struct page *page = NULL;
	spinlock_t *ptl;
	pte_t pte;
retry:
	ptl = pmd_lockptr(mm, pmd);
	spin_lock(ptl);
	/*
         * make sure that the address range covered by this pmd is not
         * unmapped from other threads.
         */
	if (!pmd_huge(*pmd))
		goto out;
	pte = huge_ptep_get((pte_t *)pmd);
	if (pte_present(pte)) {
		page = pmd_page(*pmd) + ((address & ~PMD_MASK) >> PAGE_SHIFT);
		if (flags & FOLL_GET)
			get_page(page);
	} else {
		if (is_hugetlb_entry_migration(pte)) {
			spin_unlock(ptl);
			__migration_entry_wait(mm, (pte_t *)pmd, ptl);
			goto retry;
		}
		/*
                 * hwpoisoned entry is treated as no_page_table in
                 * follow_page_mask().
                 */
	}
out:
	spin_unlock(ptl);
	return page;
}

Contributors
Person Tokens Prop Commits CommitProp
Naoya Horiguchi 112 69.57% 3 50.00%
Steve Capper 44 27.33% 1 16.67%
Aneesh Kumar K.V 4 2.48% 1 16.67%
Gerald Schaefer 1 0.62% 1 16.67%
Total 161 100.00% 6 100.00%


struct page * __weak

follow_huge_pud(struct mm_struct *mm, unsigned long address,
		pud_t *pud, int flags)
{
	if (flags & FOLL_GET)
		return NULL;

	return pte_page(*(pte_t *)pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT);
}

Contributors
Person Tokens Prop Commits CommitProp
Steve Capper 38 69.09% 1 25.00%
Naoya Horiguchi 13 23.64% 2 50.00%
Anshuman Khandual 4 7.27% 1 25.00%
Total 55 100.00% 4 100.00%


struct page * __weak

follow_huge_pgd(struct mm_struct *mm, unsigned long address, pgd_t *pgd, int flags)
{
	if (flags & FOLL_GET)
		return NULL;

	return pte_page(*(pte_t *)pgd) + ((address & ~PGDIR_MASK) >> PAGE_SHIFT);
}

Contributors
Person Tokens Prop Commits CommitProp
Anshuman Khandual 51 92.73% 1 50.00%
Steve Capper 4 7.27% 1 50.00%
Total 55 100.00% 2 100.00%



bool isolate_huge_page(struct page *page, struct list_head *list)
{
	bool ret = true;

	VM_BUG_ON_PAGE(!PageHead(page), page);
	spin_lock(&hugetlb_lock);
	if (!page_huge_active(page) || !get_page_unless_zero(page)) {
		ret = false;
		goto unlock;
	}
	clear_page_huge_active(page);
	list_move_tail(&page->lru, list);
unlock:
	spin_unlock(&hugetlb_lock);
	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
Naoya Horiguchi 83 96.51% 2 66.67%
Sasha Levin 3 3.49% 1 33.33%
Total 86 100.00% 3 100.00%



void putback_active_hugepage(struct page *page)
{
	VM_BUG_ON_PAGE(!PageHead(page), page);
	spin_lock(&hugetlb_lock);
	set_page_huge_active(page);
	list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist);
	spin_unlock(&hugetlb_lock);
	put_page(page);
}
Contributors
Person Tokens Prop Commits CommitProp
Naoya Horiguchi 58 95.08% 2 66.67%
Sasha Levin 3 4.92% 1 33.33%
Total 61 100.00% 3 100.00%

Overall Contributors
Person Tokens Prop Commits CommitProp
Andy Whitcroft 3234 17.64% 10 2.68%
Mike Kravetz 2298 12.53% 24 6.43%
Naoya Horiguchi 1487 8.11% 34 9.12%
Lee Schermerhorn 1225 6.68% 8 2.14%
Andi Kleen 1055 5.75% 8 2.14%
Nishanth Aravamudan 1025 5.59% 9 2.41%
Luiz Fernando N. Capitulino 954 5.20% 5 1.34%
Steve Capper 882 4.81% 2 0.54%
David Gibson 705 3.84% 8 2.14%
Davidlohr Bueso A 481 2.62% 6 1.61%
Mel Gorman 467 2.55% 16 4.29%
JoonSoo Kim 447 2.44% 18 4.83%
Aneesh Kumar K.V 395 2.15% 20 5.36%
Michal Hocko 369 2.01% 8 2.14%
Adam Litke 291 1.59% 16 4.29%
Kirill A. Shutemov 281 1.53% 12 3.22%
Kenneth W. Chen 272 1.48% 8 2.14%
David Rientjes 199 1.09% 7 1.88%
Hugh Dickins 170 0.93% 8 2.14%
Fengguang Wu 169 0.92% 1 0.27%
Andrea Arcangeli 162 0.88% 6 1.61%
Gerald Schaefer 151 0.82% 8 2.14%
Anshuman Khandual 128 0.70% 3 0.80%
Dave Hansen 115 0.63% 4 1.07%
Hillf Danton 110 0.60% 7 1.88%
Andrew Morton 91 0.50% 7 1.88%
Zhang Yi 86 0.47% 1 0.27%
Nicholas Piggin 70 0.38% 4 1.07%
Sagi Grimberg 65 0.35% 1 0.27%
Andreas Sandberg 62 0.34% 1 0.27%
Punit Agrawal 52 0.28% 3 0.80%
Liam R. Howlett 52 0.28% 1 0.27%
Vaishali Thakkar 51 0.28% 2 0.54%
Yanmin Zhang 48 0.26% 1 0.27%
Eric B Munson 45 0.25% 3 0.80%
Jianyu Zhan 41 0.22% 1 0.27%
Ken Chen 41 0.22% 4 1.07%
Becky Bruce 40 0.22% 1 0.27%
Sasha Levin 33 0.18% 2 0.54%
Christoph Lameter 31 0.17% 6 1.61%
Joerg Roedel 29 0.16% 2 0.54%
Matthew Wilcox 28 0.15% 1 0.27%
Peter Zijlstra 23 0.13% 1 0.27%
Rik Van Riel 23 0.13% 2 0.54%
Zhang Zhen 22 0.12% 1 0.27%
Vlastimil Babka 20 0.11% 2 0.54%
Chris Metcalf 17 0.09% 2 0.54%
Wanpeng Li 17 0.09% 2 0.54%
Motohiro Kosaki 13 0.07% 2 0.54%
Tony Lu 13 0.07% 1 0.27%
Kay Sievers 12 0.07% 1 0.27%
Masayoshi Mizuma 12 0.07% 2 0.54%
Alexey Dobriyan 11 0.06% 2 0.54%
Rafael Aquini 11 0.06% 1 0.27%
Michel Lespinasse 10 0.05% 2 0.54%
Larry Woodman 10 0.05% 1 0.27%
Nicholas Krause 9 0.05% 2 0.54%
Daniel Jordan 9 0.05% 1 0.27%
Grygorii Strashko 9 0.05% 1 0.27%
Miao Xie 8 0.04% 1 0.27%
Youquan Song 7 0.04% 1 0.27%
James Morse 7 0.04% 1 0.27%
Kamezawa Hiroyuki 7 0.04% 1 0.27%
Jon Tollefson 6 0.03% 1 0.27%
Al Viro 6 0.03% 3 0.80%
Doug Doan 6 0.03% 1 0.27%
Li Zhong 6 0.03% 1 0.27%
Dean Nelson 6 0.03% 2 0.54%
Benjamin Herrenschmidt 6 0.03% 1 0.27%
Lai Jiangshan 6 0.03% 1 0.27%
zhong jiang 5 0.03% 1 0.27%
Lucas De Marchi 5 0.03% 1 0.27%
Dan J Williams 5 0.03% 1 0.27%
Jiang Liu 5 0.03% 1 0.27%
Johannes Weiner 5 0.03% 1 0.27%
Will Deacon 5 0.03% 1 0.27%
Eric Sandeen 4 0.02% 1 0.27%
Jia He 4 0.02% 1 0.27%
Jianguo Wu 3 0.02% 1 0.27%
Linus Torvalds 3 0.02% 1 0.27%
Joe Perches 3 0.02% 1 0.27%
Adrian Bunk 3 0.02% 2 0.54%
Gideon Israel Dsouza 3 0.02% 1 0.27%
Ingo Molnar 3 0.02% 1 0.27%
Eric Paris 3 0.02% 1 0.27%
Tejun Heo 3 0.02% 1 0.27%
Wang Sheng-Hui 2 0.01% 1 0.27%
Russell King 2 0.01% 1 0.27%
Matthew Dobson 2 0.01% 1 0.27%
Jan Stancek 2 0.01% 1 0.27%
Claudiu Ghioc 2 0.01% 1 0.27%
Roel Kluin 2 0.01% 1 0.27%
Lucas Stach 2 0.01% 1 0.27%
Yisheng Xie 1 0.01% 1 0.27%
Andrey Ryabinin 1 0.01% 1 0.27%
Stephen Hemminger 1 0.01% 1 0.27%
Cyrill V. Gorcunov 1 0.01% 1 0.27%
Harvey Harrison 1 0.01% 1 0.27%
Chris Forbes 1 0.01% 1 0.27%
Geoffrey Thomas 1 0.01% 1 0.27%
Atsushi Nemoto 1 0.01% 1 0.27%
Jingoo Han 1 0.01% 1 0.27%
Alexander Kuleshov 1 0.01% 1 0.27%
Paul Gortmaker 1 0.01% 1 0.27%
Nadia Yvette Chambers 1 0.01% 1 0.27%
Total 18337 100.00% 373 100.00%
Directory: mm

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.
Person	Tokens	Prop	Commits	CommitProp
David Gibson	48	66.67%	1	50.00%
Mike Kravetz	24	33.33%	1	50.00%
Total	72	100.00%	2	100.00%
cregit-Linux how code gets into the kernel

Release 4.13 mm/hugetlb.c

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