Release 4.11 mm/swap.c

/*
 *  linux/mm/swap.c
 *
 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 */

/*
 * This file contains the default values for the operation of the
 * Linux VM subsystem. Fine-tuning documentation can be found in
 * Documentation/sysctl/vm.txt.
 * Started 18.12.91
 * Swap aging added 23.2.95, Stephen Tweedie.
 * Buffermem limits added 12.3.98, Rik van Riel.
 */

#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/kernel_stat.h>
#include <linux/swap.h>
#include <linux/mman.h>
#include <linux/pagemap.h>
#include <linux/pagevec.h>
#include <linux/init.h>
#include <linux/export.h>
#include <linux/mm_inline.h>
#include <linux/percpu_counter.h>
#include <linux/memremap.h>
#include <linux/percpu.h>
#include <linux/cpu.h>
#include <linux/notifier.h>
#include <linux/backing-dev.h>
#include <linux/memcontrol.h>
#include <linux/gfp.h>
#include <linux/uio.h>
#include <linux/hugetlb.h>
#include <linux/page_idle.h>

#include "internal.h"


#define CREATE_TRACE_POINTS
#include <trace/events/pagemap.h>

/* How many pages do we try to swap or page in/out together? */

int page_cluster;

static DEFINE_PER_CPU(struct pagevec, lru_add_pvec);
static DEFINE_PER_CPU(struct pagevec, lru_rotate_pvecs);
static DEFINE_PER_CPU(struct pagevec, lru_deactivate_file_pvecs);
static DEFINE_PER_CPU(struct pagevec, lru_deactivate_pvecs);
#ifdef CONFIG_SMP
static DEFINE_PER_CPU(struct pagevec, activate_page_pvecs);
#endif

/*
 * This path almost never happens for VM activity - pages are normally
 * freed via pagevecs.  But it gets used by networking.
 */


static void __page_cache_release(struct page *page)
{
	if (PageLRU(page)) {
		struct zone *zone = page_zone(page);
		struct lruvec *lruvec;
		unsigned long flags;

		spin_lock_irqsave(zone_lru_lock(zone), flags);
		lruvec = mem_cgroup_page_lruvec(page, zone->zone_pgdat);
		VM_BUG_ON_PAGE(!PageLRU(page), page);
		__ClearPageLRU(page);
		del_page_from_lru_list(page, lruvec, page_off_lru(page));
		spin_unlock_irqrestore(zone_lru_lock(zone), flags);
	}
	__ClearPageWaiters(page);
	mem_cgroup_uncharge(page);
}

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Mel Gorman
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Nicholas Piggin
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Johannes Weiner
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Andrea Arcangeli
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static void __put_single_page(struct page *page)
{
	__page_cache_release(page);
	free_hot_cold_page(page, false);
}

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Li Hong
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static void __put_compound_page(struct page *page)
{
	compound_page_dtor *dtor;

	/*
         * __page_cache_release() is supposed to be called for thp, not for
         * hugetlb. This is because hugetlb page does never have PageLRU set
         * (it's never listed to any LRU lists) and no memcg routines should
         * be called for hugetlb (it has a separate hugetlb_cgroup.)
         */
	if (!PageHuge(page))
		__page_cache_release(page);
	dtor = get_compound_page_dtor(page);
	(*dtor)(page);
}

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void __put_page(struct page *page)
{
	if (unlikely(PageCompound(page)))
		__put_compound_page(page);
	else
		__put_single_page(page);
}
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EXPORT_SYMBOL(__put_page);

/**
 * put_pages_list() - release a list of pages
 * @pages: list of pages threaded on page->lru
 *
 * Release a list of pages which are strung together on page.lru.  Currently
 * used by read_cache_pages() and related error recovery code.
 */


void put_pages_list(struct list_head *pages)
{
	while (!list_empty(pages)) {
		struct page *victim;

		victim = list_entry(pages->prev, struct page, lru);
		list_del(&victim->lru);
		put_page(victim);
	}
}
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EXPORT_SYMBOL(put_pages_list);

/*
 * get_kernel_pages() - pin kernel pages in memory
 * @kiov:       An array of struct kvec structures
 * @nr_segs:    number of segments to pin
 * @write:      pinning for read/write, currently ignored
 * @pages:      array that receives pointers to the pages pinned.
 *              Should be at least nr_segs long.
 *
 * Returns number of pages pinned. This may be fewer than the number
 * requested. If nr_pages is 0 or negative, returns 0. If no pages
 * were pinned, returns -errno. Each page returned must be released
 * with a put_page() call when it is finished with.
 */


int get_kernel_pages(const struct kvec *kiov, int nr_segs, int write,
		struct page **pages)
{
	int seg;

	for (seg = 0; seg < nr_segs; seg++) {
		if (WARN_ON(kiov[seg].iov_len != PAGE_SIZE))
			return seg;

		pages[seg] = kmap_to_page(kiov[seg].iov_base);
		get_page(pages[seg]);
	}

	return seg;
}
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EXPORT_SYMBOL_GPL(get_kernel_pages);

/*
 * get_kernel_page() - pin a kernel page in memory
 * @start:      starting kernel address
 * @write:      pinning for read/write, currently ignored
 * @pages:      array that receives pointer to the page pinned.
 *              Must be at least nr_segs long.
 *
 * Returns 1 if page is pinned. If the page was not pinned, returns
 * -errno. The page returned must be released with a put_page() call
 * when it is finished with.
 */


int get_kernel_page(unsigned long start, int write, struct page **pages)
{
	const struct kvec kiov = {
		.iov_base = (void *)start,
		.iov_len = PAGE_SIZE
	};

	return get_kernel_pages(&kiov, 1, write, pages);
}
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EXPORT_SYMBOL_GPL(get_kernel_page);



static void pagevec_lru_move_fn(struct pagevec *pvec,
	void (*move_fn)(struct page *page, struct lruvec *lruvec, void *arg),
	void *arg)
{
	int i;
	struct pglist_data *pgdat = NULL;
	struct lruvec *lruvec;
	unsigned long flags = 0;

	for (i = 0; i < pagevec_count(pvec); i++) {
		struct page *page = pvec->pages[i];
		struct pglist_data *pagepgdat = page_pgdat(page);

		if (pagepgdat != pgdat) {
			if (pgdat)
				spin_unlock_irqrestore(&pgdat->lru_lock, flags);
			pgdat = pagepgdat;
			spin_lock_irqsave(&pgdat->lru_lock, flags);
		}

		lruvec = mem_cgroup_page_lruvec(page, pgdat);
		(*move_fn)(page, lruvec, arg);
	}
	if (pgdat)
		spin_unlock_irqrestore(&pgdat->lru_lock, flags);
	release_pages(pvec->pages, pvec->nr, pvec->cold);
	pagevec_reinit(pvec);
}

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David Shaohua Li
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Mel Gorman
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Hugh Dickins
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static void pagevec_move_tail_fn(struct page *page, struct lruvec *lruvec,
				 void *arg)
{
	int *pgmoved = arg;

	if (PageLRU(page) && !PageUnevictable(page)) {
		del_page_from_lru_list(page, lruvec, page_lru(page));
		ClearPageActive(page);
		add_page_to_lru_list_tail(page, lruvec, page_lru(page));
		(*pgmoved)++;
	}
}

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Johannes Weiner
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Hisashi Hifumi
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Hugh Dickins
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Rik Van Riel
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/*
 * pagevec_move_tail() must be called with IRQ disabled.
 * Otherwise this may cause nasty races.
 */


static void pagevec_move_tail(struct pagevec *pvec)
{
	int pgmoved = 0;

	pagevec_lru_move_fn(pvec, pagevec_move_tail_fn, &pgmoved);
	__count_vm_events(PGROTATED, pgmoved);
}

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/*
 * Writeback is about to end against a page which has been marked for immediate
 * reclaim.  If it still appears to be reclaimable, move it to the tail of the
 * inactive list.
 */


void rotate_reclaimable_page(struct page *page)
{
	if (!PageLocked(page) && !PageDirty(page) &&
	    !PageUnevictable(page) && PageLRU(page)) {
		struct pagevec *pvec;
		unsigned long flags;

		get_page(page);
		local_irq_save(flags);
		pvec = this_cpu_ptr(&lru_rotate_pvecs);
		if (!pagevec_add(pvec, page) || PageCompound(page))
			pagevec_move_tail(pvec);
		local_irq_restore(flags);
	}
}

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Miklos Szeredi
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Hisashi Hifumi
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Lukasz Odzioba
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Lee Schermerhorn
5
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Christoph Lameter
2
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Kirill A. Shutemov
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static void update_page_reclaim_stat(struct lruvec *lruvec,
				     int file, int rotated)
{
	struct zone_reclaim_stat *reclaim_stat = &lruvec->reclaim_stat;

	reclaim_stat->recent_scanned[file]++;
	if (rotated)
		reclaim_stat->recent_rotated[file]++;
}

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static void __activate_page(struct page *page, struct lruvec *lruvec,
			    void *arg)
{
	if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
		int file = page_is_file_cache(page);
		int lru = page_lru_base_type(page);

		del_page_from_lru_list(page, lruvec, lru);
		SetPageActive(page);
		lru += LRU_ACTIVE;
		add_page_to_lru_list(page, lruvec, lru);
		trace_mm_lru_activate(page);

		__count_vm_event(PGACTIVATE);
		update_page_reclaim_stat(lruvec, file, 1);
	}
}

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Linus Torvalds
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Rik Van Riel
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Andrew Morton
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David Shaohua Li
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Motohiro Kosaki
6
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Mel Gorman
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Johannes Weiner
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Christoph Lameter
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#ifdef CONFIG_SMP


static void activate_page_drain(int cpu)
{
	struct pagevec *pvec = &per_cpu(activate_page_pvecs, cpu);

	if (pagevec_count(pvec))
		pagevec_lru_move_fn(pvec, __activate_page, NULL);
}

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static bool need_activate_page_drain(int cpu)
{
	return pagevec_count(&per_cpu(activate_page_pvecs, cpu)) != 0;
}

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void activate_page(struct page *page)
{
	page = compound_head(page);
	if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
		struct pagevec *pvec = &get_cpu_var(activate_page_pvecs);

		get_page(page);
		if (!pagevec_add(pvec, page) || PageCompound(page))
			pagevec_lru_move_fn(pvec, __activate_page, NULL);
		put_cpu_var(activate_page_pvecs);
	}
}

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Lukasz Odzioba
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#else


static inline void activate_page_drain(int cpu)
{
}

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static bool need_activate_page_drain(int cpu)
{
	return false;
}

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void activate_page(struct page *page)
{
	struct zone *zone = page_zone(page);

	page = compound_head(page);
	spin_lock_irq(zone_lru_lock(zone));
	__activate_page(page, mem_cgroup_page_lruvec(page, zone->zone_pgdat), NULL);
	spin_unlock_irq(zone_lru_lock(zone));
}
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Mel Gorman
8
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Hugh Dickins
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Andrew Morton
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#endif



static void __lru_cache_activate_page(struct page *page)
{
	struct pagevec *pvec = &get_cpu_var(lru_add_pvec);
	int i;

	/*
         * Search backwards on the optimistic assumption that the page being
         * activated has just been added to this pagevec. Note that only
         * the local pagevec is examined as a !PageLRU page could be in the
         * process of being released, reclaimed, migrated or on a remote
         * pagevec that is currently being drained. Furthermore, marking
         * a remote pagevec's page PageActive potentially hits a race where
         * a page is marked PageActive just after it is added to the inactive
         * list causing accounting errors and BUG_ON checks to trigger.
         */
	for (i = pagevec_count(pvec) - 1; i >= 0; i--) {
		struct page *pagevec_page = pvec->pages[i];

		if (pagevec_page == page) {
			SetPageActive(page);
			break;
		}
	}

	put_cpu_var(lru_add_pvec);
}

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/*
 * Mark a page as having seen activity.
 *
 * inactive,unreferenced        ->      inactive,referenced
 * inactive,referenced          ->      active,unreferenced
 * active,unreferenced          ->      active,referenced
 *
 * When a newly allocated page is not yet visible, so safe for non-atomic ops,
 * __SetPageReferenced(page) may be substituted for mark_page_accessed(page).
 */


void mark_page_accessed(struct page *page)
{
	page = compound_head(page);
	if (!PageActive(page) && !PageUnevictable(page) &&
			PageReferenced(page)) {

		/*
                 * If the page is on the LRU, queue it for activation via
                 * activate_page_pvecs. Otherwise, assume the page is on a
                 * pagevec, mark it active and it'll be moved to the active
                 * LRU on the next drain.
                 */
		if (PageLRU(page))
			activate_page(page);
		else
			__lru_cache_activate_page(page);
		ClearPageReferenced(page);
		if (page_is_file_cache(page))
			workingset_activation(page);
	} else if (!PageReferenced(page)) {
		SetPageReferenced(page);
	}
	if (page_is_idle(page))
		clear_page_idle(page);
}
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Vladimir Davydov
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Mel Gorman
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Kirill A. Shutemov
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EXPORT_SYMBOL(mark_page_accessed);



static void __lru_cache_add(struct page *page)
{
	struct pagevec *pvec = &get_cpu_var(lru_add_pvec);

	get_page(page);
	if (!pagevec_add(pvec, page) || PageCompound(page))
		__pagevec_lru_add(pvec);
	put_cpu_var(lru_add_pvec);
}

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1
10.00%
Lukasz Odzioba
8
15.38%
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Robin Dong
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7.69%
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Rusty Russell
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1
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Mel Gorman
2
3.85%
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Jianyu Zhan
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Motohiro Kosaki
1
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1
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1
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52
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10
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/**
 * lru_cache_add: add a page to the page lists
 * @page: the page to add
 */


void lru_cache_add_anon(struct page *page)
{
	if (PageActive(page))
		ClearPageActive(page);
	__lru_cache_add(page);
}

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void lru_cache_add_file(struct page *page)
{
	if (PageActive(page))
		ClearPageActive(page);
	__lru_cache_add(page);
}
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EXPORT_SYMBOL(lru_cache_add_file);

/**
 * lru_cache_add - add a page to a page list
 * @page: the page to be added to the LRU.
 *
 * Queue the page for addition to the LRU via pagevec. The decision on whether
 * to add the page to the [in]active [file|anon] list is deferred until the
 * pagevec is drained. This gives a chance for the caller of lru_cache_add()
 * have the page added to the active list using mark_page_accessed().
 */


void lru_cache_add(struct page *page)
{
	VM_BUG_ON_PAGE(PageActive(page) && PageUnevictable(page), page);
	VM_BUG_ON_PAGE(PageLRU(page), page);
	__lru_cache_add(page);
}

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10
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Sasha Levin
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2
5.00%
1
14.29%
Rusty Russell
2
5.00%
1
14.29%
Mel Gorman
1
2.50%
1
14.29%
Total
40
100.00%
7
100.00%

/**
 * add_page_to_unevictable_list - add a page to the unevictable list
 * @page:  the page to be added to the unevictable list
 *
 * Add page directly to its zone's unevictable list.  To avoid races with
 * tasks that might be making the page evictable, through eg. munlock,
 * munmap or exit, while it's not on the lru, we want to add the page
 * while it's locked or otherwise "invisible" to other tasks.  This is
 * difficult to do when using the pagevec cache, so bypass that.
 */


void add_page_to_unevictable_list(struct page *page)
{
	struct pglist_data *pgdat = page_pgdat(page);
	struct lruvec *lruvec;

	spin_lock_irq(&pgdat->lru_lock);
	lruvec = mem_cgroup_page_lruvec(page, pgdat);
	ClearPageActive(page);
	SetPageUnevictable(page);
	SetPageLRU(page);
	add_page_to_lru_list(page, lruvec, LRU_UNEVICTABLE);
	spin_unlock_irq(&pgdat->lru_lock);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Lee Schermerhorn
42
56.76%
1
25.00%
Hugh Dickins
15
20.27%
1
25.00%
Mel Gorman
12
16.22%
1
25.00%
Naoya Horiguchi
5
6.76%
1
25.00%
Total
74
100.00%
4
100.00%

/**
 * lru_cache_add_active_or_unevictable
 * @page:  the page to be added to LRU
 * @vma:   vma in which page is mapped for determining reclaimability
 *
 * Place @page on the active or unevictable LRU list, depending on its
 * evictability.  Note that if the page is not evictable, it goes
 * directly back onto it's zone's unevictable list, it does NOT use a
 * per cpu pagevec.
 */


void lru_cache_add_active_or_unevictable(struct page *page,
					 struct vm_area_struct *vma)
{
	VM_BUG_ON_PAGE(PageLRU(page), page);

	if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED)) {
		SetPageActive(page);
		lru_cache_add(page);
		return;
	}

	if (!TestSetPageMlocked(page)) {
		/*
                 * We use the irq-unsafe __mod_zone_page_stat because this
                 * counter is not modified from interrupt context, and the pte
                 * lock is held(spinlock), which implies preemption disabled.
                 */
		__mod_zone_page_state(page_zone(page), NR_MLOCK,
				    hpage_nr_pages(page));
		count_vm_event(UNEVICTABLE_PGMLOCKED);
	}
	add_page_to_unevictable_list(page);
}

Contributors
Person
Tokens
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Commits
CommitProp
Johannes Weiner
93
100.00%
1
100.00%
Total
93
100.00%
1
100.00%

/*
 * If the page can not be invalidated, it is moved to the
 * inactive list to speed up its reclaim.  It is moved to the
 * head of the list, rather than the tail, to give the flusher
 * threads some time to write it out, as this is much more
 * effective than the single-page writeout from reclaim.
 *
 * If the page isn't page_mapped and dirty/writeback, the page
 * could reclaim asap using PG_reclaim.
 *
 * 1. active, mapped page -> none
 * 2. active, dirty/writeback page -> inactive, head, PG_reclaim
 * 3. inactive, mapped page -> none
 * 4. inactive, dirty/writeback page -> inactive, head, PG_reclaim
 * 5. inactive, clean -> inactive, tail
 * 6. Others -> none
 *
 * In 4, why it moves inactive's head, the VM expects the page would
 * be write it out by flusher threads as this is much more effective
 * than the single-page writeout from reclaim.
 */


static void lru_deactivate_file_fn(struct page *page, struct lruvec *lruvec,
			      void *arg)
{
	int lru, file;
	bool active;

	if (!PageLRU(page))
		return;

	if (PageUnevictable(page))
		return;

	/* Some processes are using the page */
	if (page_mapped(page))
		return;

	active = PageActive(page);
	file = page_is_file_cache(page);
	lru = page_lru_base_type(page);

	del_page_from_lru_list(page, lruvec, lru + active);
	ClearPageActive(page);
	ClearPageReferenced(page);
	add_page_to_lru_list(page, lruvec, lru);

	if (PageWriteback(page) || PageDirty(page)) {
		/*
                 * PG_reclaim could be raced with end_page_writeback
                 * It can make readahead confusing.  But race window
                 * is _really_ small and  it's non-critical problem.
                 */
		SetPageReclaim(page);
	} else {
		/*
                 * The page's writeback ends up during pagevec
                 * We moves tha page into tail of inactive.
                 */
		list_move_tail(&page->lru, &lruvec->lists[lru]);
		__count_vm_event(PGROTATED);
	}

	if (active)
		__count_vm_event(PGDEACTIVATE);
	update_page_reclaim_stat(lruvec, file, 0);
}


Contributors
Person
Tokens
Prop
Commits
CommitProp
MinChan Kim
153
91.07%
4
50.00%
Hugh Dickins
10
5.95%
1
12.50%
Johannes Weiner
3
1.79%
2
25.00%
David Shaohua Li
2
1.19%
1
12.50%
Total
168
100.00%
8
100.00%



static void lru_deactivate_fn(struct page *page, struct lruvec *lruvec,
			    void *arg)
{
	if (PageLRU(page) && PageActive(page) && !PageUnevictable(page)) {
		int file = page_is_file_cache(page);
		int lru = page_lru_base_type(page);

		del_page_from_lru_list(page, lruvec, lru + LRU_ACTIVE);
		ClearPageActive(page);
		ClearPageReferenced(page);
		add_page_to_lru_list(page, lruvec, lru);

		__count_vm_event(PGDEACTIVATE);
		update_page_reclaim_stat(lruvec, file, 0);
	}
}

Contributors
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Tokens
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CommitProp
MinChan Kim
100
100.00%
1
100.00%
Total
100
100.00%
1
100.00%

/*
 * Drain pages out of the cpu's pagevecs.
 * Either "cpu" is the current CPU, and preemption has already been
 * disabled; or "cpu" is being hot-unplugged, and is already dead.
 */


void lru_add_drain_cpu(int cpu)
{
	struct pagevec *pvec = &per_cpu(lru_add_pvec, cpu);

	if (pagevec_count(pvec))
		__pagevec_lru_add(pvec);

	pvec = &per_cpu(lru_rotate_pvecs, cpu);
	if (pagevec_count(pvec)) {
		unsigned long flags;

		/* No harm done if a racing interrupt already did this */
		local_irq_save(flags);
		pagevec_move_tail(pvec);
		local_irq_restore(flags);
	}

	pvec = &per_cpu(lru_deactivate_file_pvecs, cpu);
	if (pagevec_count(pvec))
		pagevec_lru_move_fn(pvec, lru_deactivate_file_fn, NULL);

	pvec = &per_cpu(lru_deactivate_pvecs, cpu);
	if (pagevec_count(pvec))
		pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL);

	activate_page_drain(cpu);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
MinChan Kim
49
37.98%
3
23.08%
Hisashi Hifumi
39
30.23%
1
7.69%
Andrew Morton
25
19.38%
3
23.08%
David Shaohua Li
9
6.98%
2
15.38%
Mel Gorman
3
2.33%
1
7.69%
Motohiro Kosaki
2
1.55%
1
7.69%
Hugh Dickins
1
0.78%
1
7.69%
Konstantin Khlebnikov
1
0.78%
1
7.69%
Total
129
100.00%
13
100.00%

/**
 * deactivate_file_page - forcefully deactivate a file page
 * @page: page to deactivate
 *
 * This function hints the VM that @page is a good reclaim candidate,
 * for example if its invalidation fails due to the page being dirty
 * or under writeback.
 */


void deactivate_file_page(struct page *page)
{
	/*
         * In a workload with many unevictable page such as mprotect,
         * unevictable page deactivation for accelerating reclaim is pointless.
         */
	if (PageUnevictable(page))
		return;

	if (likely(get_page_unless_zero(page))) {
		struct pagevec *pvec = &get_cpu_var(lru_deactivate_file_pvecs);

		if (!pagevec_add(pvec, page) || PageCompound(page))
			pagevec_lru_move_fn(pvec, lru_deactivate_file_fn, NULL);
		put_cpu_var(lru_deactivate_file_pvecs);
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
MinChan Kim
61
85.92%
3
50.00%
Lukasz Odzioba
5
7.04%
1
16.67%
David Shaohua Li
4
5.63%
1
16.67%
Andrew Morton
1
1.41%
1
16.67%
Total
71
100.00%
6
100.00%

/**
 * deactivate_page - deactivate a page
 * @page: page to deactivate
 *
 * deactivate_page() moves @page to the inactive list if @page was on the active
 * list and was not an unevictable page.  This is done to accelerate the reclaim
 * of @page.
 */


void deactivate_page(struct page *page)
{
	if (PageLRU(page) && PageActive(page) && !PageUnevictable(page)) {
		struct pagevec *pvec = &get_cpu_var(lru_deactivate_pvecs);

		get_page(page);
		if (!pagevec_add(pvec, page) || PageCompound(page))
			pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL);
		put_cpu_var(lru_deactivate_pvecs);
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
MinChan Kim
69
92.00%
1
33.33%
Lukasz Odzioba
5
6.67%
1
33.33%
Kirill A. Shutemov
1
1.33%
1
33.33%
Total
75
100.00%
3
100.00%



void lru_add_drain(void)
{
	lru_add_drain_cpu(get_cpu());
	put_cpu();
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
11
68.75%
1
25.00%
Rusty Russell
2
12.50%
1
25.00%
Linus Torvalds (pre-git)
2
12.50%
1
25.00%
Konstantin Khlebnikov
1
6.25%
1
25.00%
Total
16
100.00%
4
100.00%



static void lru_add_drain_per_cpu(struct work_struct *dummy)
{
	lru_add_drain();
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Nicholas Piggin
12
85.71%
1
50.00%
David Howells
2
14.29%
1
50.00%
Total
14
100.00%
2
100.00%

static DEFINE_PER_CPU(struct work_struct, lru_add_drain_work);



void lru_add_drain_all(void)
{
	static DEFINE_MUTEX(lock);
	static struct cpumask has_work;
	int cpu;

	/*
         * Make sure nobody triggers this path before mm_percpu_wq is fully
         * initialized.
         */
	if (WARN_ON(!mm_percpu_wq))
		return;

	mutex_lock(&lock);
	get_online_cpus();
	cpumask_clear(&has_work);

	for_each_online_cpu(cpu) {
		struct work_struct *work = &per_cpu(lru_add_drain_work, cpu);

		if (pagevec_count(&per_cpu(lru_add_pvec, cpu)) ||
		    pagevec_count(&per_cpu(lru_rotate_pvecs, cpu)) ||
		    pagevec_count(&per_cpu(lru_deactivate_file_pvecs, cpu)) ||
		    pagevec_count(&per_cpu(lru_deactivate_pvecs, cpu)) ||
		    need_activate_page_drain(cpu)) {
			INIT_WORK(work, lru_add_drain_per_cpu);
			queue_work_on(cpu, mm_percpu_wq, work);
			cpumask_set_cpu(cpu, &has_work);
		}
	}

	for_each_cpu(cpu, &has_work)
		flush_work(&per_cpu(lru_add_drain_work, cpu));

	put_online_cpus();
	mutex_unlock(&lock);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Chris Metcalf
134
79.76%
1
16.67%
MinChan Kim
12
7.14%
2
33.33%
Michal Hocko
11
6.55%
1
16.67%
Nicholas Piggin
9
5.36%
1
16.67%
Wang Sheng-Hui
2
1.19%
1
16.67%
Total
168
100.00%
6
100.00%

/**
 * release_pages - batched put_page()
 * @pages: array of pages to release
 * @nr: number of pages
 * @cold: whether the pages are cache cold
 *
 * Decrement the reference count on all the pages in @pages.  If it
 * fell to zero, remove the page from the LRU and free it.
 */


void release_pages(struct page **pages, int nr, bool cold)
{
	int i;
	LIST_HEAD(pages_to_free);
	struct pglist_data *locked_pgdat = NULL;
	struct lruvec *lruvec;
	unsigned long uninitialized_var(flags);
	unsigned int uninitialized_var(lock_batch);

	for (i = 0; i < nr; i++) {
		struct page *page = pages[i];

		/*
                 * Make sure the IRQ-safe lock-holding time does not get
                 * excessive with a continuous string of pages from the
                 * same pgdat. The lock is held only if pgdat != NULL.
                 */
		if (locked_pgdat && ++lock_batch == SWAP_CLUSTER_MAX) {
			spin_unlock_irqrestore(&locked_pgdat->lru_lock, flags);
			locked_pgdat = NULL;
		}

		if (is_huge_zero_page(page))
			continue;

		page = compound_head(page);
		if (!put_page_testzero(page))
			continue;

		if (PageCompound(page)) {
			if (locked_pgdat) {
				spin_unlock_irqrestore(&locked_pgdat->lru_lock, flags);
				locked_pgdat = NULL;
			}
			__put_compound_page(page);
			continue;
		}

		if (PageLRU(page)) {
			struct pglist_data *pgdat = page_pgdat(page);

			if (pgdat != locked_pgdat) {
				if (locked_pgdat)
					spin_unlock_irqrestore(&locked_pgdat->lru_lock,
									flags);
				lock_batch = 0;
				locked_pgdat = pgdat;
				spin_lock_irqsave(&locked_pgdat->lru_lock, flags);
			}

			lruvec = mem_cgroup_page_lruvec(page, locked_pgdat);
			VM_BUG_ON_PAGE(!PageLRU(page), page);
			__ClearPageLRU(page);
			del_page_from_lru_list(page, lruvec, page_off_lru(page));
		}

		/* Clear Active bit in case of parallel mark_page_accessed */
		__ClearPageActive(page);
		__ClearPageWaiters(page);

		list_add(&page->lru, &pages_to_free);
	}
	if (locked_pgdat)
		spin_unlock_irqrestore(&locked_pgdat->lru_lock, flags);

	mem_cgroup_uncharge_list(&pages_to_free);
	free_hot_cold_page_list(&pages_to_free, cold);
}
Contributors
Person
Tokens
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Commits
CommitProp
Andrew Morton
100
32.57%
4
17.39%
Nicholas Piggin
44
14.33%
5
21.74%
Mel Gorman
44
14.33%
4
17.39%
Kirill A. Shutemov
35
11.40%
2
8.70%
Michal Hocko
25
8.14%
1
4.35%
Hugh Dickins
21
6.84%
2
8.70%
Hisashi Hifumi
20
6.51%
1
4.35%
Konstantin Khlebnikov
9
2.93%
1
4.35%
Johannes Weiner
6
1.95%
2
8.70%
Sasha Levin
3
0.98%
1
4.35%
Total
307
100.00%
23
100.00%


EXPORT_SYMBOL(release_pages);

/*
 * The pages which we're about to release may be in the deferred lru-addition
 * queues.  That would prevent them from really being freed right now.  That's
 * OK from a correctness point of view but is inefficient - those pages may be
 * cache-warm and we want to give them back to the page allocator ASAP.
 *
 * So __pagevec_release() will drain those queues here.  __pagevec_lru_add()
 * and __pagevec_lru_add_active() call release_pages() directly to avoid
 * mutual recursion.
 */


void __pagevec_release(struct pagevec *pvec)
{
	lru_add_drain();
	release_pages(pvec->pages, pagevec_count(pvec), pvec->cold);
	pagevec_reinit(pvec);
}
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Andrew Morton
34
100.00%
4
100.00%
Total
34
100.00%
4
100.00%


EXPORT_SYMBOL(__pagevec_release);

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
/* used by __split_huge_page_refcount() */


void lru_add_page_tail(struct page *page, struct page *page_tail,
		       struct lruvec *lruvec, struct list_head *list)
{
	const int file = 0;

	VM_BUG_ON_PAGE(!PageHead(page), page);
	VM_BUG_ON_PAGE(PageCompound(page_tail), page);
	VM_BUG_ON_PAGE(PageLRU(page_tail), page);
	VM_BUG_ON(NR_CPUS != 1 &&
		  !spin_is_locked(&lruvec_pgdat(lruvec)->lru_lock));

	if (!list)
		SetPageLRU(page_tail);

	if (likely(PageLRU(page)))
		list_add_tail(&page_tail->lru, &page->lru);
	else if (list) {
		/* page reclaim is reclaiming a huge page */
		get_page(page_tail);
		list_add_tail(&page_tail->lru, list);
	} else {
		struct list_head *list_head;
		/*
                 * Head page has not yet been counted, as an hpage,
                 * so we must account for each subpage individually.
                 *
                 * Use the standard add function to put page_tail on the list,
                 * but then correct its position so they all end up in order.
                 */
		add_page_to_lru_list(page_tail, lruvec, page_lru(page_tail));
		list_head = page_tail->lru.prev;
		list_move_tail(&page_tail->lru, list_head);
	}

	if (!PageUnevictable(page))
		update_page_reclaim_stat(lruvec, file, PageActive(page_tail));
}
Contributors
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Tokens
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Commits
CommitProp
Andrea Arcangeli
81
41.33%
1
9.09%
Hugh Dickins
52
26.53%
4
36.36%
Shaohua Li
33
16.84%
1
9.09%
Sasha Levin
9
4.59%
1
9.09%
Johannes Weiner
9
4.59%
2
18.18%
Kirill A. Shutemov
8
4.08%
1
9.09%
Mel Gorman
4
2.04%
1
9.09%
Total
196
100.00%
11
100.00%

#endif /* CONFIG_TRANSPARENT_HUGEPAGE */



static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec,
				 void *arg)
{
	int file = page_is_file_cache(page);
	int active = PageActive(page);
	enum lru_list lru = page_lru(page);

	VM_BUG_ON_PAGE(PageLRU(page), page);

	SetPageLRU(page);
	add_page_to_lru_list(page, lruvec, lru);
	update_page_reclaim_stat(lruvec, file, active);
	trace_mm_lru_insertion(page, lru);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Mel Gorman
17
20.00%
2
14.29%
Hugh Dickins
15
17.65%
3
21.43%
Andrew Morton
12
14.12%
1
7.14%
David Shaohua Li
11
12.94%
1
7.14%
Motohiro Kosaki
8
9.41%
2
14.29%
Nicholas Piggin
7
8.24%
1
7.14%
Lee Schermerhorn
4
4.71%
1
7.14%
Rik Van Riel
4
4.71%
1
7.14%
Linus Torvalds
4
4.71%
1
7.14%
Sasha Levin
3
3.53%
1
7.14%
Total
85
100.00%
14
100.00%

/*
 * Add the passed pages to the LRU, then drop the caller's refcount
 * on them.  Reinitialises the caller's pagevec.
 */


void __pagevec_lru_add(struct pagevec *pvec)
{
	pagevec_lru_move_fn(pvec, __pagevec_lru_add_fn, NULL);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
David Shaohua Li
9
47.37%
1
20.00%
Andrew Morton
7
36.84%
2
40.00%
Hugh Dickins
2
10.53%
1
20.00%
Mel Gorman
1
5.26%
1
20.00%
Total
19
100.00%
5
100.00%


EXPORT_SYMBOL(__pagevec_lru_add);

/**
 * pagevec_lookup_entries - gang pagecache lookup
 * @pvec:       Where the resulting entries are placed
 * @mapping:    The address_space to search
 * @start:      The starting entry index
 * @nr_entries: The maximum number of entries
 * @indices:    The cache indices corresponding to the entries in @pvec
 *
 * pagevec_lookup_entries() will search for and return a group of up
 * to @nr_entries pages and shadow entries in the mapping.  All
 * entries are placed in @pvec.  pagevec_lookup_entries() takes a
 * reference against actual pages in @pvec.
 *
 * The search returns a group of mapping-contiguous entries with
 * ascending indexes.  There may be holes in the indices due to
 * not-present entries.
 *
 * pagevec_lookup_entries() returns the number of entries which were
 * found.
 */


unsigned pagevec_lookup_entries(struct pagevec *pvec,
				struct address_space *mapping,
				pgoff_t start, unsigned nr_pages,
				pgoff_t *indices)
{
	pvec->nr = find_get_entries(mapping, start, nr_pages,
				    pvec->pages, indices);
	return pagevec_count(pvec);
}

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Johannes Weiner
50
100.00%
1
100.00%
Total
50
100.00%
1
100.00%

/**
 * pagevec_remove_exceptionals - pagevec exceptionals pruning
 * @pvec:       The pagevec to prune
 *
 * pagevec_lookup_entries() fills both pages and exceptional radix
 * tree entries into the pagevec.  This function prunes all
 * exceptionals from @pvec without leaving holes, so that it can be
 * passed on to page-only pagevec operations.
 */


void pagevec_remove_exceptionals(struct pagevec *pvec)
{
	int i, j;

	for (i = 0, j = 0; i < pagevec_count(pvec); i++) {
		struct page *page = pvec->pages[i];
		if (!radix_tree_exceptional_entry(page))
			pvec->pages[j++] = page;
	}
	pvec->nr = j;
}

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Johannes Weiner
73
100.00%
1
100.00%
Total
73
100.00%
1
100.00%

/**
 * pagevec_lookup - gang pagecache lookup
 * @pvec:       Where the resulting pages are placed
 * @mapping:    The address_space to search
 * @start:      The starting page index
 * @nr_pages:   The maximum number of pages
 *
 * pagevec_lookup() will search for and return a group of up to @nr_pages pages
 * in the mapping.  The pages are placed in @pvec.  pagevec_lookup() takes a
 * reference against the pages in @pvec.
 *
 * The search returns a group of mapping-contiguous pages with ascending
 * indexes.  There may be holes in the indices due to not-present pages.
 *
 * pagevec_lookup() returns the number of pages which were found.
 */


unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping,
		pgoff_t start, unsigned nr_pages)
{
	pvec->nr = find_get_pages(mapping, start, nr_pages, pvec->pages);
	return pagevec_count(pvec);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
44
100.00%
2
100.00%
Total
44
100.00%
2
100.00%


EXPORT_SYMBOL(pagevec_lookup);



unsigned pagevec_lookup_tag(struct pagevec *pvec, struct address_space *mapping,
		pgoff_t *index, int tag, unsigned nr_pages)
{
	pvec->nr = find_get_pages_tag(mapping, index, tag,
					nr_pages, pvec->pages);
	return pagevec_count(pvec);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
50
100.00%
2
100.00%
Total
50
100.00%
2
100.00%


EXPORT_SYMBOL(pagevec_lookup_tag);

/*
 * Perform any setup for the swap system
 */


void __init swap_setup(void)
{
	unsigned long megs = totalram_pages >> (20 - PAGE_SHIFT);

	/* Use a smaller cluster for small-memory machines */
	if (megs < 16)
		page_cluster = 2;
	else
		page_cluster = 3;
	/*
         * Right now other parts of the system means that we
         * _really_ don't want to cluster much more
         */
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds
20
54.05%
2
50.00%
Linus Torvalds (pre-git)
16
43.24%
1
25.00%
Jan Beulich
1
2.70%
1
25.00%
Total
37
100.00%
4
100.00%

Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
MinChan Kim
465
13.25%
6
4.44%
Andrew Morton
455
12.96%
19
14.07%
Mel Gorman
386
11.00%
13
9.63%
David Shaohua Li
317
9.03%
2
1.48%
Johannes Weiner
278
7.92%
9
6.67%
Hugh Dickins
204
5.81%
9
6.67%
Hisashi Hifumi
193
5.50%
1
0.74%
Chris Metcalf
178
5.07%
1
0.74%
Andrea Arcangeli
127
3.62%
3
2.22%
Nicholas Piggin
96
2.74%
6
4.44%
Linus Torvalds (pre-git)
83
2.36%
10
7.41%
Lee Schermerhorn
78
2.22%
2
1.48%
Kirill A. Shutemov
75
2.14%
7
5.19%
Adrian Bunk
66
1.88%
1
0.74%
Motohiro Kosaki
62
1.77%
2
1.48%
Alexander Zarochentzev
56
1.60%
1
0.74%
Linus Torvalds
46
1.31%
5
3.70%
Jianyu Zhan
44
1.25%
1
0.74%
Michal Hocko
36
1.03%
2
1.48%
Shaohua Li
33
0.94%
1
0.74%
Lukasz Odzioba
28
0.80%
1
0.74%
Miklos Szeredi
27
0.77%
3
2.22%
Sasha Levin
24
0.68%
1
0.74%
Rik Van Riel
22
0.63%
2
1.48%
Naoya Horiguchi
19
0.54%
2
1.48%
Vladimir Davydov
15
0.43%
1
0.74%
Rusty Russell
14
0.40%
2
1.48%
Ming Li
14
0.40%
1
0.74%
Konstantin Khlebnikov
11
0.31%
2
1.48%
Steve French
10
0.28%
1
0.74%
Christoph Hellwig
5
0.14%
1
0.74%
Pravin B Shelar
5
0.14%
1
0.74%
Arnaldo Carvalho de Melo
5
0.14%
1
0.74%
Robin Dong
4
0.11%
1
0.74%
Christoph Lameter
4
0.11%
2
1.48%
Balbir Singh
3
0.09%
1
0.74%
Peter Zijlstra
3
0.09%
1
0.74%
Dan J Williams
3
0.09%
1
0.74%
Kent Overstreet
3
0.09%
1
0.74%
Tejun Heo
3
0.09%
1
0.74%
Li Hong
2
0.06%
1
0.74%
David Howells
2
0.06%
1
0.74%
Wang Sheng-Hui
2
0.06%
1
0.74%
Jan Beulich
1
0.03%
1
0.74%
Paul Gortmaker
1
0.03%
1
0.74%
Simon Arlott
1
0.03%
1
0.74%
Randy Dunlap
1
0.03%
1
0.74%
Total
3510
100.00%
135
100.00%
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