cregit-Linux how code gets into the kernel

Release 4.11 mm/zsmalloc.c

Directory: mm
/*
 * zsmalloc memory allocator
 *
 * Copyright (C) 2011  Nitin Gupta
 * Copyright (C) 2012, 2013 Minchan Kim
 *
 * This code is released using a dual license strategy: BSD/GPL
 * You can choose the license that better fits your requirements.
 *
 * Released under the terms of 3-clause BSD License
 * Released under the terms of GNU General Public License Version 2.0
 */

/*
 * Following is how we use various fields and flags of underlying
 * struct page(s) to form a zspage.
 *
 * Usage of struct page fields:
 *      page->private: points to zspage
 *      page->freelist(index): links together all component pages of a zspage
 *              For the huge page, this is always 0, so we use this field
 *              to store handle.
 *      page->units: first object offset in a subpage of zspage
 *
 * Usage of struct page flags:
 *      PG_private: identifies the first component page
 *      PG_owner_priv_1: identifies the huge component page
 *
 */


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/magic.h>
#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/highmem.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <asm/tlbflush.h>
#include <asm/pgtable.h>
#include <linux/cpumask.h>
#include <linux/cpu.h>
#include <linux/vmalloc.h>
#include <linux/preempt.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/debugfs.h>
#include <linux/zsmalloc.h>
#include <linux/zpool.h>
#include <linux/mount.h>
#include <linux/migrate.h>
#include <linux/pagemap.h>


#define ZSPAGE_MAGIC	0x58

/*
 * This must be power of 2 and greater than of equal to sizeof(link_free).
 * These two conditions ensure that any 'struct link_free' itself doesn't
 * span more than 1 page which avoids complex case of mapping 2 pages simply
 * to restore link_free pointer values.
 */

#define ZS_ALIGN		8

/*
 * A single 'zspage' is composed of up to 2^N discontiguous 0-order (single)
 * pages. ZS_MAX_ZSPAGE_ORDER defines upper limit on N.
 */

#define ZS_MAX_ZSPAGE_ORDER 2

#define ZS_MAX_PAGES_PER_ZSPAGE (_AC(1, UL) << ZS_MAX_ZSPAGE_ORDER)


#define ZS_HANDLE_SIZE (sizeof(unsigned long))

/*
 * Object location (<PFN>, <obj_idx>) is encoded as
 * as single (unsigned long) handle value.
 *
 * Note that object index <obj_idx> starts from 0.
 *
 * This is made more complicated by various memory models and PAE.
 */

#ifndef MAX_PHYSMEM_BITS
#ifdef CONFIG_HIGHMEM64G

#define MAX_PHYSMEM_BITS 36
#else /* !CONFIG_HIGHMEM64G */
/*
 * If this definition of MAX_PHYSMEM_BITS is used, OBJ_INDEX_BITS will just
 * be PAGE_SHIFT
 */

#define MAX_PHYSMEM_BITS BITS_PER_LONG
#endif
#endif

#define _PFN_BITS		(MAX_PHYSMEM_BITS - PAGE_SHIFT)

/*
 * Memory for allocating for handle keeps object position by
 * encoding <page, obj_idx> and the encoded value has a room
 * in least bit(ie, look at obj_to_location).
 * We use the bit to synchronize between object access by
 * user and migration.
 */

#define HANDLE_PIN_BIT	0

/*
 * Head in allocated object should have OBJ_ALLOCATED_TAG
 * to identify the object was allocated or not.
 * It's okay to add the status bit in the least bit because
 * header keeps handle which is 4byte-aligned address so we
 * have room for two bit at least.
 */

#define OBJ_ALLOCATED_TAG 1

#define OBJ_TAG_BITS 1

#define OBJ_INDEX_BITS	(BITS_PER_LONG - _PFN_BITS - OBJ_TAG_BITS)

#define OBJ_INDEX_MASK	((_AC(1, UL) << OBJ_INDEX_BITS) - 1)


#define MAX(a, b) ((a) >= (b) ? (a) : (b))
/* ZS_MIN_ALLOC_SIZE must be multiple of ZS_ALIGN */

#define ZS_MIN_ALLOC_SIZE \
	MAX(32, (ZS_MAX_PAGES_PER_ZSPAGE << PAGE_SHIFT >> OBJ_INDEX_BITS))
/* each chunk includes extra space to keep handle */

#define ZS_MAX_ALLOC_SIZE	PAGE_SIZE

/*
 * On systems with 4K page size, this gives 255 size classes! There is a
 * trader-off here:
 *  - Large number of size classes is potentially wasteful as free page are
 *    spread across these classes
 *  - Small number of size classes causes large internal fragmentation
 *  - Probably its better to use specific size classes (empirically
 *    determined). NOTE: all those class sizes must be set as multiple of
 *    ZS_ALIGN to make sure link_free itself never has to span 2 pages.
 *
 *  ZS_MIN_ALLOC_SIZE and ZS_SIZE_CLASS_DELTA must be multiple of ZS_ALIGN
 *  (reason above)
 */

#define ZS_SIZE_CLASS_DELTA	(PAGE_SIZE >> CLASS_BITS)


enum fullness_group {
	
ZS_EMPTY,
	
ZS_ALMOST_EMPTY,
	
ZS_ALMOST_FULL,
	
ZS_FULL,
	
NR_ZS_FULLNESS,
};


enum zs_stat_type {
	
CLASS_EMPTY,
	
CLASS_ALMOST_EMPTY,
	
CLASS_ALMOST_FULL,
	
CLASS_FULL,
	
OBJ_ALLOCATED,
	
OBJ_USED,
	
NR_ZS_STAT_TYPE,
};


struct zs_size_stat {
	
unsigned long objs[NR_ZS_STAT_TYPE];
};

#ifdef CONFIG_ZSMALLOC_STAT

static struct dentry *zs_stat_root;
#endif

#ifdef CONFIG_COMPACTION

static struct vfsmount *zsmalloc_mnt;
#endif

/*
 * number of size_classes
 */

static int zs_size_classes;

/*
 * We assign a page to ZS_ALMOST_EMPTY fullness group when:
 *      n <= N / f, where
 * n = number of allocated objects
 * N = total number of objects zspage can store
 * f = fullness_threshold_frac
 *
 * Similarly, we assign zspage to:
 *      ZS_ALMOST_FULL  when n > N / f
 *      ZS_EMPTY        when n == 0
 *      ZS_FULL         when n == N
 *
 * (see: fix_fullness_group())
 */

static const int fullness_threshold_frac = 4;


struct size_class {
	
spinlock_t lock;
	
struct list_head fullness_list[NR_ZS_FULLNESS];
	/*
         * Size of objects stored in this class. Must be multiple
         * of ZS_ALIGN.
         */
	
int size;
	
int objs_per_zspage;
	/* Number of PAGE_SIZE sized pages to combine to form a 'zspage' */
	
int pages_per_zspage;

	
unsigned int index;
	
struct zs_size_stat stats;
};

/* huge object: pages_per_zspage == 1 && maxobj_per_zspage == 1 */

static void SetPageHugeObject(struct page *page) { SetPageOwnerPriv1(page); }

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static void ClearPageHugeObject(struct page *page) { ClearPageOwnerPriv1(page); }

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static int PageHugeObject(struct page *page) { return PageOwnerPriv1(page); }

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/* * Placed within free objects to form a singly linked list. * For every zspage, zspage->freeobj gives head of this list. * * This must be power of 2 and less than or equal to ZS_ALIGN */ struct link_free { union { /* * Free object index; * It's valid for non-allocated object */ unsigned long next; /* * Handle of allocated object. */ unsigned long handle; }; }; struct zs_pool { const char *name; struct size_class **size_class; struct kmem_cache *handle_cachep; struct kmem_cache *zspage_cachep; atomic_long_t pages_allocated; struct zs_pool_stats stats; /* Compact classes */ struct shrinker shrinker; /* * To signify that register_shrinker() was successful * and unregister_shrinker() will not Oops. */ bool shrinker_enabled; #ifdef CONFIG_ZSMALLOC_STAT struct dentry *stat_dentry; #endif #ifdef CONFIG_COMPACTION struct inode *inode; struct work_struct free_work; #endif }; #define FULLNESS_BITS 2 #define CLASS_BITS 8 #define ISOLATED_BITS 3 #define MAGIC_VAL_BITS 8 struct zspage { struct { unsigned int fullness:FULLNESS_BITS; unsigned int class:CLASS_BITS + 1; unsigned int isolated:ISOLATED_BITS; unsigned int magic:MAGIC_VAL_BITS; }; unsigned int inuse; unsigned int freeobj; struct page *first_page; struct list_head list; /* fullness list */ #ifdef CONFIG_COMPACTION rwlock_t lock; #endif }; struct mapping_area { #ifdef CONFIG_PGTABLE_MAPPING struct vm_struct *vm; /* vm area for mapping object that span pages */ #else char *vm_buf; /* copy buffer for objects that span pages */ #endif char *vm_addr; /* address of kmap_atomic()'ed pages */ enum zs_mapmode vm_mm; /* mapping mode */ }; #ifdef CONFIG_COMPACTION static int zs_register_migration(struct zs_pool *pool); static void zs_unregister_migration(struct zs_pool *pool); static void migrate_lock_init(struct zspage *zspage); static void migrate_read_lock(struct zspage *zspage); static void migrate_read_unlock(struct zspage *zspage); static void kick_deferred_free(struct zs_pool *pool); static void init_deferred_free(struct zs_pool *pool); static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage); #else
static int zsmalloc_mount(void) { return 0; }

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static void zsmalloc_unmount(void) {}

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static int zs_register_migration(struct zs_pool *pool) { return 0; }

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static void zs_unregister_migration(struct zs_pool *pool) {}

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static void migrate_lock_init(struct zspage *zspage) {}

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static void migrate_read_lock(struct zspage *zspage) {}

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static void migrate_read_unlock(struct zspage *zspage) {}

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static void kick_deferred_free(struct zs_pool *pool) {}

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static void init_deferred_free(struct zs_pool *pool) {}

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static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage) {}

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#endif
static int create_cache(struct zs_pool *pool) { pool->handle_cachep = kmem_cache_create("zs_handle", ZS_HANDLE_SIZE, 0, 0, NULL); if (!pool->handle_cachep) return 1; pool->zspage_cachep = kmem_cache_create("zspage", sizeof(struct zspage), 0, 0, NULL); if (!pool->zspage_cachep) { kmem_cache_destroy(pool->handle_cachep); pool->handle_cachep = NULL; return 1; } return 0; }

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static void destroy_cache(struct zs_pool *pool) { kmem_cache_destroy(pool->handle_cachep); kmem_cache_destroy(pool->zspage_cachep); }

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static unsigned long cache_alloc_handle(struct zs_pool *pool, gfp_t gfp) { return (unsigned long)kmem_cache_alloc(pool->handle_cachep, gfp & ~(__GFP_HIGHMEM|__GFP_MOVABLE)); }

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static void cache_free_handle(struct zs_pool *pool, unsigned long handle) { kmem_cache_free(pool->handle_cachep, (void *)handle); }

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static struct zspage *cache_alloc_zspage(struct zs_pool *pool, gfp_t flags) { return kmem_cache_alloc(pool->zspage_cachep, flags & ~(__GFP_HIGHMEM|__GFP_MOVABLE)); }

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static void cache_free_zspage(struct zs_pool *pool, struct zspage *zspage) { kmem_cache_free(pool->zspage_cachep, zspage); }

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static void record_obj(unsigned long handle, unsigned long obj) { /* * lsb of @obj represents handle lock while other bits * represent object value the handle is pointing so * updating shouldn't do store tearing. */ WRITE_ONCE(*(unsigned long *)handle, obj); }

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/* zpool driver */ #ifdef CONFIG_ZPOOL
static void *zs_zpool_create(const char *name, gfp_t gfp, const struct zpool_ops *zpool_ops, struct zpool *zpool) { /* * Ignore global gfp flags: zs_malloc() may be invoked from * different contexts and its caller must provide a valid * gfp mask. */ return zs_create_pool(name); }

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static void zs_zpool_destroy(void *pool) { zs_destroy_pool(pool); }

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static int zs_zpool_malloc(void *pool, size_t size, gfp_t gfp, unsigned long *handle) { *handle = zs_malloc(pool, size, gfp); return *handle ? 0 : -1; }

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static void zs_zpool_free(void *pool, unsigned long handle) { zs_free(pool, handle); }

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static int zs_zpool_shrink(void *pool, unsigned int pages, unsigned int *reclaimed) { return -EINVAL; }

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static void *zs_zpool_map(void *pool, unsigned long handle, enum zpool_mapmode mm) { enum zs_mapmode zs_mm; switch (mm) { case ZPOOL_MM_RO: zs_mm = ZS_MM_RO; break; case ZPOOL_MM_WO: zs_mm = ZS_MM_WO; break; case ZPOOL_MM_RW: /* fallthru */ default: zs_mm = ZS_MM_RW; break; } return zs_map_object(pool, handle, zs_mm); }

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static void zs_zpool_unmap(void *pool, unsigned long handle) { zs_unmap_object(pool, handle); }

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static u64 zs_zpool_total_size(void *pool) { return zs_get_total_pages(pool) << PAGE_SHIFT; }

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static struct zpool_driver zs_zpool_driver = { .type = "zsmalloc", .owner = THIS_MODULE, .create = zs_zpool_create, .destroy = zs_zpool_destroy, .malloc = zs_zpool_malloc, .free = zs_zpool_free, .shrink = zs_zpool_shrink, .map = zs_zpool_map, .unmap = zs_zpool_unmap, .total_size = zs_zpool_total_size, }; MODULE_ALIAS("zpool-zsmalloc"); #endif /* CONFIG_ZPOOL */ /* per-cpu VM mapping areas for zspage accesses that cross page boundaries */ static DEFINE_PER_CPU(struct mapping_area, zs_map_area);
static bool is_zspage_isolated(struct zspage *zspage) { return zspage->isolated; }

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static int is_first_page(struct page *page) { return PagePrivate(page); }

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/* Protected by class->lock */
static inline int get_zspage_inuse(struct zspage *zspage) { return zspage->inuse; }

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static inline void set_zspage_inuse(struct zspage *zspage, int val) { zspage->inuse = val; }

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static inline void mod_zspage_inuse(struct zspage *zspage, int val) { zspage->inuse += val; }

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static inline struct page *get_first_page(struct zspage *zspage) { struct page *first_page = zspage->first_page; VM_BUG_ON_PAGE(!is_first_page(first_page), first_page); return first_page; }

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static inline int get_first_obj_offset(struct page *page) { return page->units; }

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static inline void set_first_obj_offset(struct page *page, int offset) { page->units = offset; }

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static inline unsigned int get_freeobj(struct zspage *zspage) { return zspage->freeobj; }

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static inline void set_freeobj(struct zspage *zspage, unsigned int obj) { zspage->freeobj = obj; }

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static void get_zspage_mapping(struct zspage *zspage, unsigned int *class_idx, enum fullness_group *fullness) { BUG_ON(zspage->magic != ZSPAGE_MAGIC); *fullness = zspage->fullness; *class_idx = zspage->class; }

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static void set_zspage_mapping(struct zspage *zspage, unsigned int class_idx, enum fullness_group fullness) { zspage->class = class_idx; zspage->fullness = fullness; }

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/* * zsmalloc divides the pool into various size classes where each * class maintains a list of zspages where each zspage is divided * into equal sized chunks. Each allocation falls into one of these * classes depending on its size. This function returns index of the * size class which has chunk size big enough to hold the give size. */
static int get_size_class_index(int size) { int idx = 0; if (likely(size > ZS_MIN_ALLOC_SIZE)) idx = DIV_ROUND_UP(size - ZS_MIN_ALLOC_SIZE, ZS_SIZE_CLASS_DELTA); return min(zs_size_classes - 1, idx); }

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static inline void zs_stat_inc(struct size_class *class, enum zs_stat_type type, unsigned long cnt) { class->stats.objs[type] += cnt; }

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static inline void zs_stat_dec(struct size_class *class, enum zs_stat_type type, unsigned long cnt) { class->stats.objs[type] -= cnt; }

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static inline unsigned long zs_stat_get(struct size_class *class, enum zs_stat_type type) { return class->stats.objs[type]; }

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#ifdef CONFIG_ZSMALLOC_STAT
static void __init zs_stat_init(void) { if (!debugfs_initialized()) { pr_warn("debugfs not available, stat dir not created\n"); return; } zs_stat_root = debugfs_create_dir("zsmalloc", NULL); if (!zs_stat_root) pr_warn("debugfs 'zsmalloc' stat dir creation failed\n"); }

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static void __exit zs_stat_exit(void) { debugfs_remove_recursive(zs_stat_root); }

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static unsigned long zs_can_compact(struct size_class *class);
static int zs_stats_size_show(struct seq_file *s, void *v) { int i; struct zs_pool *pool = s->private; struct size_class *class; int objs_per_zspage; unsigned long class_almost_full, class_almost_empty; unsigned long obj_allocated, obj_used, pages_used, freeable; unsigned long total_class_almost_full = 0, total_class_almost_empty = 0; unsigned long total_objs = 0, total_used_objs = 0, total_pages = 0; unsigned long total_freeable = 0; seq_printf(s, " %5s %5s %11s %12s %13s %10s %10s %16s %8s\n", "class", "size", "almost_full", "almost_empty", "obj_allocated", "obj_used", "pages_used", "pages_per_zspage", "freeable"); for (i = 0; i < zs_size_classes; i++) { class = pool->size_class[i]; if (class->index != i) continue; spin_lock(&class->lock); class_almost_full = zs_stat_get(class, CLASS_ALMOST_FULL); class_almost_empty = zs_stat_get(class, CLASS_ALMOST_EMPTY); obj_allocated = zs_stat_get(class, OBJ_ALLOCATED); obj_used = zs_stat_get(class, OBJ_USED); freeable = zs_can_compact(class); spin_unlock(&class->lock); objs_per_zspage = class->objs_per_zspage; pages_used = obj_allocated / objs_per_zspage * class->pages_per_zspage; seq_printf(s, " %5u %5u %11lu %12lu %13lu" " %10lu %10lu %16d %8lu\n", i, class->size, class_almost_full, class_almost_empty, obj_allocated, obj_used, pages_used, class->pages_per_zspage, freeable); total_class_almost_full += class_almost_full; total_class_almost_empty += class_almost_empty; total_objs += obj_allocated; total_used_objs += obj_used; total_pages += pages_used; total_freeable += freeable; } seq_puts(s, "\n"); seq_printf(s, " %5s %5s %11lu %12lu %13lu %10lu %10lu %16s %8lu\n", "Total", "", total_class_almost_full, total_class_almost_empty, total_objs, total_used_objs, total_pages, "", total_freeable); return 0; }

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Ganesh Mahendran10.33%125.00%
Total303100.00%4100.00%


static int zs_stats_size_open(struct inode *inode, struct file *file) { return single_open(file, zs_stats_size_show, inode->i_private); }

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Nitin Gupta1139.29%150.00%
Total28100.00%2100.00%

static const struct file_operations zs_stat_size_ops = { .open = zs_stats_size_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, };
static void zs_pool_stat_create(struct zs_pool *pool, const char *name) { struct dentry *entry; if (!zs_stat_root) { pr_warn("no root stat dir, not creating <%s> stat dir\n", name); return; } entry = debugfs_create_dir(name, zs_stat_root); if (!entry) { pr_warn("debugfs dir <%s> creation failed\n", name); return; } pool->stat_dentry = entry; entry = debugfs_create_file("classes", S_IFREG | S_IRUGO, pool->stat_dentry, pool, &zs_stat_size_ops); if (!entry) { pr_warn("%s: debugfs file entry <%s> creation failed\n", name, "classes"); debugfs_remove_recursive(pool->stat_dentry); pool->stat_dentry = NULL; } }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim5446.96%233.33%
Nitin Gupta3429.57%116.67%
Dan Streetman2521.74%233.33%
Sunghan Suh21.74%116.67%
Total115100.00%6100.00%


static void zs_pool_stat_destroy(struct zs_pool *pool) { debugfs_remove_recursive(pool->stat_dentry); }

Contributors

PersonTokensPropCommitsCommitProp
Nitin Gupta1161.11%150.00%
MinChan Kim738.89%150.00%
Total18100.00%2100.00%

#else /* CONFIG_ZSMALLOC_STAT */
static void __init zs_stat_init(void) { }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim675.00%266.67%
Dan Streetman225.00%133.33%
Total8100.00%3100.00%


static void __exit zs_stat_exit(void) { }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim8100.00%2100.00%
Total8100.00%2100.00%


static inline void zs_pool_stat_create(struct zs_pool *pool, const char *name) { }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim1487.50%375.00%
Dan Streetman212.50%125.00%
Total16100.00%4100.00%


static inline void zs_pool_stat_destroy(struct zs_pool *pool) { }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim981.82%150.00%
Nitin Gupta218.18%150.00%
Total11100.00%2100.00%

#endif /* * For each size class, zspages are divided into different groups * depending on how "full" they are. This was done so that we could * easily find empty or nearly empty zspages when we try to shrink * the pool (not yet implemented). This function returns fullness * status of the given page. */
static enum fullness_group get_fullness_group(struct size_class *class, struct zspage *zspage) { int inuse, objs_per_zspage; enum fullness_group fg; inuse = get_zspage_inuse(zspage); objs_per_zspage = class->objs_per_zspage; if (inuse == 0) fg = ZS_EMPTY; else if (inuse == objs_per_zspage) fg = ZS_FULL; else if (inuse <= 3 * objs_per_zspage / fullness_threshold_frac) fg = ZS_ALMOST_EMPTY; else fg = ZS_ALMOST_FULL; return fg; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim7286.75%480.00%
Nitin Gupta1113.25%120.00%
Total83100.00%5100.00%

/* * Each size class maintains various freelists and zspages are assigned * to one of these freelists based on the number of live objects they * have. This functions inserts the given zspage into the freelist * identified by <class, fullness_group>. */
static void insert_zspage(struct size_class *class, struct zspage *zspage, enum fullness_group fullness) { struct zspage *head; zs_stat_inc(class, fullness, 1); head = list_first_entry_or_null(&class->fullness_list[fullness], struct zspage, list); /* * We want to see more ZS_FULL pages and less almost empty/full. * Put pages with higher ->inuse first. */ if (head) { if (get_zspage_inuse(zspage) < get_zspage_inuse(head)) { list_add(&zspage->list, &head->list); return; } } list_add(&zspage->list, &class->fullness_list[fullness]); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim8481.55%457.14%
Nitin Gupta1716.50%228.57%
Sergey Senozhatsky21.94%114.29%
Total103100.00%7100.00%

/* * This function removes the given zspage from the freelist identified * by <class, fullness_group>. */
static void remove_zspage(struct size_class *class, struct zspage *zspage, enum fullness_group fullness) { VM_BUG_ON(list_empty(&class->fullness_list[fullness])); VM_BUG_ON(is_zspage_isolated(zspage)); list_del_init(&zspage->list); zs_stat_dec(class, fullness, 1); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim4067.80%480.00%
Nitin Gupta1932.20%120.00%
Total59100.00%5100.00%

/* * Each size class maintains zspages in different fullness groups depending * on the number of live objects they contain. When allocating or freeing * objects, the fullness status of the page can change, say, from ALMOST_FULL * to ALMOST_EMPTY when freeing an object. This function checks if such * a status change has occurred for the given page and accordingly moves the * page from the freelist of the old fullness group to that of the new * fullness group. */
static enum fullness_group fix_fullness_group(struct size_class *class, struct zspage *zspage) { int class_idx; enum fullness_group currfg, newfg; get_zspage_mapping(zspage, &class_idx, &currfg); newfg = get_fullness_group(class, zspage); if (newfg == currfg) goto out; if (!is_zspage_isolated(zspage)) { remove_zspage(class, zspage, currfg); insert_zspage(class, zspage, newfg); } set_zspage_mapping(zspage, class_idx, newfg); out: return newfg; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim6567.01%571.43%
Nitin Gupta3131.96%114.29%
Seth Jennings11.03%114.29%
Total97100.00%7100.00%

/* * We have to decide on how many pages to link together * to form a zspage for each size class. This is important * to reduce wastage due to unusable space left at end of * each zspage which is given as: * wastage = Zp % class_size * usage = Zp - wastage * where Zp = zspage size = k * PAGE_SIZE where k = 1, 2, ... * * For example, for size class of 3/8 * PAGE_SIZE, we should * link together 3 PAGE_SIZE sized pages to form a zspage * since then we can perfectly fit in 8 such objects. */
static int get_pages_per_zspage(int class_size) { int i, max_usedpc = 0; /* zspage order which gives maximum used size per KB */ int max_usedpc_order = 1; for (i = 1; i <= ZS_MAX_PAGES_PER_ZSPAGE; i++) { int zspage_size; int waste, usedpc; zspage_size = i * PAGE_SIZE; waste = zspage_size % class_size; usedpc = (zspage_size - waste) * 100 / zspage_size; if (usedpc > max_usedpc) { max_usedpc = usedpc; max_usedpc_order = i; } } return max_usedpc_order; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim6371.59%150.00%
Nitin Gupta2528.41%150.00%
Total88100.00%2100.00%


static struct zspage *get_zspage(struct page *page) { struct zspage *zspage = (struct zspage *)page->private; BUG_ON(zspage->magic != ZSPAGE_MAGIC); return zspage; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim2461.54%360.00%
Nitin Gupta1025.64%120.00%
Kirill A. Shutemov512.82%120.00%
Total39100.00%5100.00%


static struct page *get_next_page(struct page *page) { if (unlikely(PageHugeObject(page))) return NULL; return page->freelist; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim2374.19%360.00%
Seth Jennings825.81%240.00%
Total31100.00%5100.00%

/** * obj_to_location - get (<page>, <obj_idx>) from encoded object value * @page: page object resides in zspage * @obj_idx: object index */
static void obj_to_location(unsigned long obj, struct page **page, unsigned int *obj_idx) { obj >>= OBJ_TAG_BITS; *page = pfn_to_page(obj >> OBJ_INDEX_BITS); *obj_idx = (obj & OBJ_INDEX_MASK); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim3477.27%250.00%
Seth Jennings1022.73%250.00%
Total44100.00%4100.00%

/** * location_to_obj - get obj value encoded from (<page>, <obj_idx>) * @page: page object resides in zspage * @obj_idx: object index */
static unsigned long location_to_obj(struct page *page, unsigned int obj_idx) { unsigned long obj; obj = page_to_pfn(page) << OBJ_INDEX_BITS; obj |= obj_idx & OBJ_INDEX_MASK; obj <<= OBJ_TAG_BITS; return obj; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim3173.81%250.00%
Seth Jennings1126.19%250.00%
Total42100.00%4100.00%


static unsigned long handle_to_obj(unsigned long handle) { return *(unsigned long *)handle; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim1785.00%133.33%
Seth Jennings315.00%266.67%
Total20100.00%3100.00%


static unsigned long obj_to_head(struct page *page, void *obj) { if (unlikely(PageHugeObject(page))) { VM_BUG_ON_PAGE(!is_first_page(page), page); return page->index; } else return *(unsigned long *)obj; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim4583.33%466.67%
Seth Jennings916.67%233.33%
Total54100.00%6100.00%


static inline int testpin_tag(unsigned long handle) { return bit_spin_is_locked(HANDLE_PIN_BIT, (unsigned long *)handle); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim24100.00%1100.00%
Total24100.00%1100.00%


static inline int trypin_tag(unsigned long handle) { return bit_spin_trylock(HANDLE_PIN_BIT, (unsigned long *)handle); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim2395.83%266.67%
Seth Jennings14.17%133.33%
Total24100.00%3100.00%


static void pin_tag(unsigned long handle) { bit_spin_lock(HANDLE_PIN_BIT, (unsigned long *)handle); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim2195.45%266.67%
Seth Jennings14.55%133.33%
Total22100.00%3100.00%


static void unpin_tag(unsigned long handle) { bit_spin_unlock(HANDLE_PIN_BIT, (unsigned long *)handle); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim1463.64%266.67%
Seth Jennings836.36%133.33%
Total22100.00%3100.00%


static void reset_page(struct page *page) { __ClearPageMovable(page); ClearPagePrivate(page); set_page_private(page, 0); page_mapcount_reset(page); ClearPageHugeObject(page); page->freelist = NULL; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim3068.18%240.00%
Seth Jennings1329.55%240.00%
Ganesh Mahendran12.27%120.00%
Total44100.00%5100.00%

/* * To prevent zspage destroy during migration, zspage freeing should * hold locks of all pages in the zspage. */
void lock_zspage(struct zspage *zspage) { struct page *page = get_first_page(zspage); do { lock_page(page); } while ((page = get_next_page(page)) != NULL); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim42100.00%1100.00%
Total42100.00%1100.00%


int trylock_zspage(struct zspage *zspage) { struct page *cursor, *fail; for (cursor = get_first_page(zspage); cursor != NULL; cursor = get_next_page(cursor)) { if (!trylock_page(cursor)) { fail = cursor; goto unlock; } } return 1; unlock: for (cursor = get_first_page(zspage); cursor != fail; cursor = get_next_page(cursor)) unlock_page(cursor); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim90100.00%1100.00%
Total90100.00%1100.00%


static void __free_zspage(struct zs_pool *pool, struct size_class *class, struct zspage *zspage) { struct page *page, *next; enum fullness_group fg; unsigned int class_idx; get_zspage_mapping(zspage, &class_idx, &fg); assert_spin_locked(&class->lock); VM_BUG_ON(get_zspage_inuse(zspage)); VM_BUG_ON(fg != ZS_EMPTY); next = page = get_first_page(zspage); do { VM_BUG_ON_PAGE(!PageLocked(page), page); next = get_next_page(page); reset_page(page); unlock_page(page); dec_zone_page_state(page, NR_ZSPAGES); put_page(page); page = next; } while (page != NULL); cache_free_zspage(pool, zspage); zs_stat_dec(class, OBJ_ALLOCATED, class->objs_per_zspage); atomic_long_sub(class->pages_per_zspage, &pool->pages_allocated); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim15594.51%571.43%
Seth Jennings84.88%114.29%
Ganesh Mahendran10.61%114.29%
Total164100.00%7100.00%


static void free_zspage(struct zs_pool *pool, struct size_class *class, struct zspage *zspage) { VM_BUG_ON(get_zspage_inuse(zspage)); VM_BUG_ON(list_empty(&zspage->list)); if (!trylock_zspage(zspage)) { kick_deferred_free(pool); return; } remove_zspage(class, zspage, ZS_EMPTY); __free_zspage(pool, class, zspage); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim6486.49%480.00%
Seth Jennings1013.51%120.00%
Total74100.00%5100.00%

/* Initialize a newly allocated zspage */
static void init_zspage(struct size_class *class, struct zspage *zspage) { unsigned int freeobj = 1; unsigned long off = 0; struct page *page = get_first_page(zspage); while (page) { struct page *next_page; struct link_free *link; void *vaddr; set_first_obj_offset(page, off); vaddr = kmap_atomic(page); link = (struct link_free *)vaddr + off / sizeof(*link); while ((off += class->size) < PAGE_SIZE) { link->next = freeobj++ << OBJ_TAG_BITS; link += class->size / sizeof(*link); } /* * We now come to the last (full or partial) object on this * page, which must point to the first object on the next * page (if present) */ next_page = get_next_page(page); if (next_page) { link->next = freeobj++ << OBJ_TAG_BITS; } else { /* * Reset OBJ_TAG_BITS bit to last link to tell * whether it's allocated object or not. */ link->next = -1 << OBJ_TAG_BITS; } kunmap_atomic(vaddr); page = next_page; off %= PAGE_SIZE; } set_freeobj(zspage, 0); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim15787.22%880.00%
Seth Jennings2312.78%220.00%
Total180100.00%10100.00%


static void create_page_chain(struct size_class *class, struct zspage *zspage, struct page *pages[]) { int i; struct page *page; struct page *prev_page = NULL; int nr_pages = class->pages_per_zspage; /* * Allocate individual pages and link them together as: * 1. all pages are linked together using page->freelist * 2. each sub-page point to zspage using page->private * * we set PG_private to identify the first page (i.e. no other sub-page * has this flag set). */ for (i = 0; i < nr_pages; i++) { page = pages[i]; set_page_private(page, (unsigned long)zspage); page->freelist = NULL; if (i == 0) { zspage->first_page = page; SetPagePrivate(page); if (unlikely(class->objs_per_zspage == 1 && class->pages_per_zspage == 1)) SetPageHugeObject(page); } else { prev_page->freelist = page; } prev_page = page; } }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim11684.06%440.00%
Nitin Gupta1510.87%110.00%
Srivatsa S. Bhat21.45%110.00%
Kirill A. Shutemov21.45%110.00%
Ganesh Mahendran10.72%110.00%
Yisheng Xie10.72%110.00%
Seth Jennings10.72%110.00%
Total138100.00%10100.00%

/* * Allocate a zspage for the given size class */
static struct zspage *alloc_zspage(struct zs_pool *pool, struct size_class *class, gfp_t gfp) { int i; struct page *pages[ZS_MAX_PAGES_PER_ZSPAGE]; struct zspage *zspage = cache_alloc_zspage(pool, gfp); if (!zspage) return NULL; memset(zspage, 0, sizeof(struct zspage)); zspage->magic = ZSPAGE_MAGIC; migrate_lock_init(zspage); for (i = 0; i < class->pages_per_zspage; i++) { struct page *page; page = alloc_page(gfp); if (!page) { while (--i >= 0) { dec_zone_page_state(pages[i], NR_ZSPAGES); __free_page(pages[i]); } cache_free_zspage(pool, zspage); return NULL; } inc_zone_page_state(page, NR_ZSPAGES); pages[i] = page; } create_page_chain(class, zspage, pages); init_zspage(class, zspage); return zspage; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim17797.25%666.67%
Ganesh Mahendran31.65%222.22%
Nitin Gupta21.10%111.11%
Total182100.00%9100.00%


static struct zspage *find_get_zspage(struct size_class *class) { int i; struct zspage *zspage; for (i = ZS_ALMOST_FULL; i >= ZS_EMPTY; i--) { zspage = list_first_entry_or_null(&class->fullness_list[i], struct zspage, list); if (zspage) break; } return zspage; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim5588.71%375.00%
JoonSoo Kim711.29%125.00%
Total62100.00%4100.00%

#ifdef CONFIG_PGTABLE_MAPPING
static inline int __zs_cpu_up(struct mapping_area *area) { /* * Make sure we don't leak memory if a cpu UP notification * and zs_init() race and both call zs_cpu_up() on the same cpu */ if (area->vm) return 0; area->vm = alloc_vm_area(PAGE_SIZE * 2, NULL); if (!area->vm) return -ENOMEM; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim2755.10%150.00%
JoonSoo Kim2244.90%150.00%
Total49100.00%2100.00%


static inline void __zs_cpu_down(struct mapping_area *area) { if (area->vm) free_vm_area(area->vm); area->vm = NULL; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim31100.00%2100.00%
Total31100.00%2100.00%


static inline void *__zs_map_object(struct mapping_area *area, struct page *pages[2], int off, int size) { BUG_ON(map_vm_area(area->vm, PAGE_KERNEL, pages)); area->vm_addr = area->vm->addr; return area->vm_addr + off; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim4577.59%133.33%
Ganesh Mahendran1322.41%266.67%
Total58100.00%3100.00%


static inline void __zs_unmap_object(struct mapping_area *area, struct page *pages[2], int off, int size) { unsigned long addr = (unsigned long)area->vm_addr; unmap_kernel_range(addr, PAGE_SIZE * 2); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim3472.34%125.00%
Ganesh Mahendran919.15%250.00%
Nitin Gupta48.51%125.00%
Total47100.00%4100.00%

#else /* CONFIG_PGTABLE_MAPPING */
static inline int __zs_cpu_up(struct mapping_area *area) { /* * Make sure we don't leak memory if a cpu UP notification * and zs_init() race and both call zs_cpu_up() on the same cpu */ if (area->vm_buf) return 0; area->vm_buf = kmalloc(ZS_MAX_ALLOC_SIZE, GFP_KERNEL); if (!area->vm_buf) return -ENOMEM; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Ganesh Mahendran2348.94%240.00%
MinChan Kim1838.30%120.00%
Nitin Gupta36.38%120.00%
JoonSoo Kim36.38%120.00%
Total47100.00%5100.00%


static inline void __zs_cpu_down(struct mapping_area *area) { kfree(area->vm_buf); area->vm_buf = NULL; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim1664.00%150.00%
Ganesh Mahendran936.00%150.00%
Total25100.00%2100.00%


static void *__zs_map_object(struct mapping_area *area, struct page *pages[2], int off, int size) { int sizes[2]; void *addr; char *buf = area->vm_buf; /* disable page faults to match kmap_atomic() return conditions */ pagefault_disable(); /* no read fastpath */ if (area->vm_mm == ZS_MM_WO) goto out; sizes[0] = PAGE_SIZE - off; sizes[1] = size - sizes[0]; /* copy object to per-cpu buffer */ addr = kmap_atomic(pages[0]); memcpy(buf, addr + off, sizes[0]); kunmap_atomic(addr); addr = kmap_atomic(pages[1]); memcpy(buf + sizes[0], addr, sizes[1]); kunmap_atomic(addr); out: return area->vm_buf; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim11274.67%150.00%
Ganesh Mahendran3825.33%150.00%
Total150100.00%2100.00%


static void __zs_unmap_object(struct mapping_area *area, struct page *pages[2], int off, int size) { int sizes[2]; void *addr; char *buf; /* no write fastpath */ if (area->vm_mm == ZS_MM_RO) goto out; buf = area->vm_buf; buf = buf + ZS_HANDLE_SIZE; size -= ZS_HANDLE_SIZE; off += ZS_HANDLE_SIZE; sizes[0] = PAGE_SIZE - off; sizes[1] = size - sizes[0]; /* copy per-cpu buffer to object */ addr = kmap_atomic(pages[0]); memcpy(addr + off, buf, sizes[0]); kunmap_atomic(addr); addr = kmap_atomic(pages[1]); memcpy(addr, buf + sizes[0], sizes[1]); kunmap_atomic(addr); out: /* enable page faults to match kunmap_atomic() return conditions */ pagefault_enable(); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim13886.25%150.00%
Ganesh Mahendran2213.75%150.00%
Total160100.00%2100.00%

#endif /* CONFIG_PGTABLE_MAPPING */
static int zs_cpu_prepare(unsigned int cpu) { struct mapping_area *area; area = &per_cpu(zs_map_area, cpu); return __zs_cpu_up(area); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim1961.29%133.33%
Ganesh Mahendran825.81%133.33%
Sebastian Andrzej Siewior412.90%133.33%
Total31100.00%3100.00%


static int zs_cpu_dead(unsigned int cpu) { struct mapping_area *area; area = &per_cpu(zs_map_area, cpu); __zs_cpu_down(area); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Sebastian Andrzej Siewior1545.45%133.33%
Ganesh Mahendran1339.39%133.33%
MinChan Kim515.15%133.33%
Total33100.00%3100.00%


static void __init init_zs_size_classes(void) { int nr; nr = (ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE) / ZS_SIZE_CLASS_DELTA + 1; if ((ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE) % ZS_SIZE_CLASS_DELTA) nr += 1; zs_size_classes = nr; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim3685.71%133.33%
Ganesh Mahendran614.29%266.67%
Total42100.00%3100.00%


static bool can_merge(struct size_class *prev, int pages_per_zspage, int objs_per_zspage) { if (prev->pages_per_zspage == pages_per_zspage && prev->objs_per_zspage == objs_per_zspage) return true; return false; }

Contributors

PersonTokensPropCommitsCommitProp
Ganesh Mahendran2054.05%375.00%
MinChan Kim1745.95%125.00%
Total37100.00%4100.00%


static bool zspage_full(struct size_class *class, struct zspage *zspage) { return get_zspage_inuse(zspage) == class->objs_per_zspage; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim1765.38%480.00%
Ganesh Mahendran934.62%120.00%
Total26100.00%5100.00%


unsigned long zs_get_total_pages(struct zs_pool *pool) { return atomic_long_read(&pool->pages_allocated); }

Contributors

PersonTokensPropCommitsCommitProp
Ganesh Mahendran20100.00%1100.00%
Total20100.00%1100.00%

EXPORT_SYMBOL_GPL(zs_get_total_pages); /** * zs_map_object - get address of allocated object from handle. * @pool: pool from which the object was allocated * @handle: handle returned from zs_malloc * * Before using an object allocated from zs_malloc, it must be mapped using * this function. When done with the object, it must be unmapped using * zs_unmap_object. * * Only one object can be mapped per cpu at a time. There is no protection * against nested mappings. * * This function returns with preemption and page faults disabled. */
void *zs_map_object(struct zs_pool *pool, unsigned long handle, enum zs_mapmode mm) { struct zspage *zspage; struct page *page; unsigned long obj, off; unsigned int obj_idx; unsigned int class_idx; enum fullness_group fg; struct size_class *class; struct mapping_area *area; struct page *pages[2]; void *ret; /* * Because we use per-cpu mapping areas shared among the * pools/users, we can't allow mapping in interrupt context * because it can corrupt another users mappings. */ WARN_ON_ONCE(in_interrupt()); /* From now on, migration cannot move the object */ pin_tag(handle); obj = handle_to_obj(handle); obj_to_location(obj, &page, &obj_idx); zspage = get_zspage(page); /* migration cannot move any subpage in this zspage */ migrate_read_lock(zspage); get_zspage_mapping(zspage, &class_idx, &fg); class = pool->size_class[class_idx]; off = (class->size * obj_idx) & ~PAGE_MASK; area = &get_cpu_var(zs_map_area); area->vm_mm = mm; if (off + class->size <= PAGE_SIZE) { /* this object is contained entirely within a page */ area->vm_addr = kmap_atomic(page); ret = area->vm_addr + off; goto out; } /* this object spans two pages */ pages[0] = page; pages[1] = get_next_page(page); BUG_ON(!pages[1]); ret = __zs_map_object(area, pages, off, class->size); out: if (likely(!PageHugeObject(page))) ret += ZS_HANDLE_SIZE; return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Ganesh Mahendran16062.75%325.00%
MinChan Kim7830.59%758.33%
JoonSoo Kim93.53%18.33%
Nitin Gupta83.14%18.33%
Total255100.00%12100.00%

EXPORT_SYMBOL_GPL(zs_map_object);
void zs_unmap_object(struct zs_pool *pool, unsigned long handle) { struct zspage *zspage; struct page *page; unsigned long obj, off; unsigned int obj_idx; unsigned int class_idx; enum fullness_group fg; struct size_class *class; struct mapping_area *area; obj = handle_to_obj(handle); obj_to_location(obj, &page, &obj_idx); zspage = get_zspage(page); get_zspage_mapping(zspage, &class_idx, &fg); class = pool->size_class[class_idx]; off = (class->size * obj_idx) & ~PAGE_MASK; area = this_cpu_ptr(&zs_map_area); if (off + class->size <= PAGE_SIZE) kunmap_atomic(area->vm_addr); else { struct page *pages[2]; pages[0] = page; pages[1] = get_next_page(page); BUG_ON(!pages[1]); __zs_unmap_object(area, pages, off, class->size); } put_cpu_var(zs_map_area); migrate_read_unlock(zspage); unpin_tag(handle); }

Contributors

PersonTokensPropCommitsCommitProp
Ganesh Mahendran11758.50%222.22%
MinChan Kim4321.50%555.56%
Nitin Gupta3517.50%111.11%
JoonSoo Kim52.50%111.11%
Total200100.00%9100.00%

EXPORT_SYMBOL_GPL(zs_unmap_object);
static unsigned long obj_malloc(struct size_class *class, struct zspage *zspage, unsigned long handle) { int i, nr_page, offset; unsigned long obj; struct link_free *link; struct page *m_page; unsigned long m_offset; void *vaddr; handle |= OBJ_ALLOCATED_TAG; obj = get_freeobj(zspage); offset = obj * class->size; nr_page = offset >> PAGE_SHIFT; m_offset = offset & ~PAGE_MASK; m_page = get_first_page(zspage); for (i = 0; i < nr_page; i++) m_page = get_next_page(m_page); vaddr = kmap_atomic(m_page); link = (struct link_free *)vaddr + m_offset / sizeof(*link); set_freeobj(zspage, link->next >> OBJ_TAG_BITS); if (likely(!PageHugeObject(m_page))) /* record handle in the header of allocated chunk */ link->handle = handle; else /* record handle to page->index */ zspage->first_page->index = handle; kunmap_atomic(vaddr); mod_zspage_inuse(zspage, 1); zs_stat_inc(class, OBJ_USED, 1); obj = location_to_obj(m_page, obj); return obj; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim205100.00%9100.00%
Total205100.00%9100.00%

/** * zs_malloc - Allocate block of given size from pool. * @pool: pool to allocate from * @size: size of block to allocate * @gfp: gfp flags when allocating object * * On success, handle to the allocated object is returned, * otherwise 0. * Allocation requests with size > ZS_MAX_ALLOC_SIZE will fail. */
unsigned long zs_malloc(struct zs_pool *pool, size_t size, gfp_t gfp) { unsigned long handle, obj; struct size_class *class; enum fullness_group newfg; struct zspage *zspage; if (unlikely(!size || size > ZS_MAX_ALLOC_SIZE)) return 0; handle = cache_alloc_handle(pool, gfp); if (!handle) return 0; /* extra space in chunk to keep the handle */ size += ZS_HANDLE_SIZE; class = pool->size_class[get_size_class_index(size)]; spin_lock(&class->lock); zspage = find_get_zspage(class); if (likely(zspage)) { obj = obj_malloc(class, zspage, handle); /* Now move the zspage to another fullness group, if required */ fix_fullness_group(class, zspage); record_obj(handle, obj); spin_unlock(&class->lock); return handle; } spin_unlock(&class->lock); zspage = alloc_zspage(pool, class, gfp); if (!zspage) { cache_free_handle(pool, handle); return 0; } spin_lock(&class->lock); obj = obj_malloc(class, zspage, handle); newfg = get_fullness_group(class, zspage); insert_zspage(class, zspage, newfg); set_zspage_mapping(zspage, class->index, newfg); record_obj(handle, obj); atomic_long_add(class->pages_per_zspage, &pool->pages_allocated); zs_stat_inc(class, OBJ_ALLOCATED, class->objs_per_zspage); /* We completely set up zspage so mark them as movable */ SetZsPageMovable(pool, zspage); spin_unlock(&class->lock); return handle; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim15053.57%758.33%
Nitin Gupta10637.86%18.33%
Ganesh Mahendran155.36%216.67%
Sergey Senozhatsky62.14%18.33%
JoonSoo Kim31.07%18.33%
Total280100.00%12100.00%

EXPORT_SYMBOL_GPL(zs_malloc);
static void obj_free(struct size_class *class, unsigned long obj) { struct link_free *link; struct zspage *zspage; struct page *f_page; unsigned long f_offset; unsigned int f_objidx; void *vaddr; obj &= ~OBJ_ALLOCATED_TAG; obj_to_location(obj, &f_page, &f_objidx); f_offset = (class->size * f_objidx) & ~PAGE_MASK; zspage = get_zspage(f_page); vaddr = kmap_atomic(f_page); /* Insert this object in containing zspage's freelist */ link = (struct link_free *)(vaddr + f_offset); link->next = get_freeobj(zspage) << OBJ_TAG_BITS; kunmap_atomic(vaddr); set_freeobj(zspage, f_objidx); mod_zspage_inuse(zspage, -1); zs_stat_dec(class, OBJ_USED, 1); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim8158.27%1090.91%
Nitin Gupta5841.73%19.09%
Total139100.00%11100.00%


void zs_free(struct zs_pool *pool, unsigned long handle) { struct zspage *zspage; struct page *f_page; unsigned long obj; unsigned int f_objidx; int class_idx; struct size_class *class; enum fullness_group fullness; bool isolated; if (unlikely(!handle)) return; pin_tag(handle); obj = handle_to_obj(handle); obj_to_location(obj, &f_page, &f_objidx); zspage = get_zspage(f_page); migrate_read_lock(zspage); get_zspage_mapping(zspage, &class_idx, &fullness); class = pool->size_class[class_idx]; spin_lock(&class->lock); obj_free(class, obj); fullness = fix_fullness_group(class, zspage); if (fullness != ZS_EMPTY) { migrate_read_unlock(zspage); goto out; } isolated = is_zspage_isolated(zspage); migrate_read_unlock(zspage); /* If zspage is isolated, zs_page_putback will free the zspage */ if (likely(!isolated)) free_zspage(pool, class, zspage); out: spin_unlock(&class->lock); unpin_tag(handle); cache_free_handle(pool, handle); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim18088.67%675.00%
Ganesh Mahendran157.39%112.50%
Nitin Gupta83.94%112.50%
Total203100.00%8100.00%

EXPORT_SYMBOL_GPL(zs_free);
static void zs_object_copy(struct size_class *class, unsigned long dst, unsigned long src) { struct page *s_page, *d_page; unsigned int s_objidx, d_objidx; unsigned long s_off, d_off; void *s_addr, *d_addr; int s_size, d_size, size; int written = 0; s_size = d_size = class->size; obj_to_location(src, &s_page, &s_objidx); obj_to_location(dst, &d_page, &d_objidx); s_off = (class->size * s_objidx) & ~PAGE_MASK; d_off = (class->size * d_objidx) & ~PAGE_MASK; if (s_off + class->size > PAGE_SIZE) s_size = PAGE_SIZE - s_off; if (d_off + class->size > PAGE_SIZE) d_size = PAGE_SIZE - d_off; s_addr = kmap_atomic(s_page); d_addr = kmap_atomic(d_page); while (1) { size = min(s_size, d_size); memcpy(d_addr + d_off, s_addr + s_off, size); written += size; if (written == class->size) break; s_off += size; s_size -= size; d_off += size; d_size -= size; if (s_off >= PAGE_SIZE) { kunmap_atomic(d_addr); kunmap_atomic(s_addr); s_page = get_next_page(s_page); s_addr = kmap_atomic(s_page); d_addr = kmap_atomic(d_page); s_size = class->size - written; s_off = 0; } if (d_off >= PAGE_SIZE) { kunmap_atomic(d_addr); d_page = get_next_page(d_page); d_addr = kmap_atomic(d_page); d_size = class->size - written; d_off = 0; } } kunmap_atomic(d_addr); kunmap_atomic(s_addr); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim29994.32%360.00%
Sergey Senozhatsky185.68%240.00%
Total317100.00%5100.00%

/* * Find alloced object in zspage from index object and * return handle. */
static unsigned long find_alloced_obj(struct size_class *class, struct page *page, int *obj_idx) { unsigned long head; int offset = 0; int index = *obj_idx; unsigned long handle = 0; void *addr = kmap_atomic(page); offset = get_first_obj_offset(page); offset += class->size * index; while (offset < PAGE_SIZE) { head = obj_to_head(page, addr + offset); if (head & OBJ_ALLOCATED_TAG) { handle = head & ~OBJ_ALLOCATED_TAG; if (trypin_tag(handle)) break; handle = 0; } offset += class->size; index++; } kunmap_atomic(addr); *obj_idx = index; return handle; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim12190.30%480.00%
Ganesh Mahendran139.70%120.00%
Total134100.00%5100.00%

struct zs_compact_control { /* Source spage for migration which could be a subpage of zspage */ struct page *s_page; /* Destination page for migration which should be a first page * of zspage. */ struct page *d_page; /* Starting object index within @s_page which used for live object * in the subpage. */ int obj_idx; };
static int migrate_zspage(struct zs_pool *pool, struct size_class *class, struct zs_compact_control *cc) { unsigned long used_obj, free_obj; unsigned long handle; struct page *s_page = cc->s_page; struct page *d_page = cc->d_page; int obj_idx = cc->obj_idx; int ret = 0; while (1) { handle = find_alloced_obj(class, s_page, &obj_idx); if (!handle) { s_page = get_next_page(s_page); if (!s_page) break; obj_idx = 0; continue; } /* Stop if there is no more space */ if (zspage_full(class, get_zspage(d_page))) { unpin_tag(handle); ret = -ENOMEM; break; } used_obj = handle_to_obj(handle); free_obj = obj_malloc(class, get_zspage(d_page), handle); zs_object_copy(class, free_obj, used_obj); obj_idx++; /* * record_obj updates handle's value to free_obj and it will * invalidate lock bit(ie, HANDLE_PIN_BIT) of handle, which * breaks synchronization using pin_tag(e,g, zs_free) so * let's keep the lock bit. */ free_obj |= BIT(HANDLE_PIN_BIT); record_obj(handle, free_obj); unpin_tag(handle); obj_free(class, used_obj); } /* Remember last position in this iteration */ cc->s_page = s_page; cc->obj_idx = obj_idx; return ret; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim18891.26%450.00%
Ganesh Mahendran94.37%225.00%
Junil Lee83.88%112.50%
Sergey Senozhatsky10.49%112.50%
Total206100.00%8100.00%


static struct zspage *isolate_zspage(struct size_class *class, bool source) { int i; struct zspage *zspage; enum fullness_group fg[2] = {ZS_ALMOST_EMPTY, ZS_ALMOST_FULL}; if (!source) { fg[0] = ZS_ALMOST_FULL; fg[1] = ZS_ALMOST_EMPTY; } for (i = 0; i < 2; i++) { zspage = list_first_entry_or_null(&class->fullness_list[fg[i]], struct zspage, list); if (zspage) { VM_BUG_ON(is_zspage_isolated(zspage)); remove_zspage(class, zspage, fg[i]); return zspage; } } return zspage; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim126100.00%3100.00%
Total126100.00%3100.00%

/* * putback_zspage - add @zspage into right class's fullness list * @class: destination class * @zspage: target page * * Return @zspage's fullness_group */
static enum fullness_group putback_zspage(struct size_class *class, struct zspage *zspage) { enum fullness_group fullness; VM_BUG_ON(is_zspage_isolated(zspage)); fullness = get_fullness_group(class, zspage); insert_zspage(class, zspage, fullness); set_zspage_mapping(zspage, class->index, fullness); return fullness; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim61100.00%1100.00%
Total61100.00%1100.00%

#ifdef CONFIG_COMPACTION
static struct dentry *zs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) { static const struct dentry_operations ops = { .d_dname = simple_dname, }; return mount_pseudo(fs_type, "zsmalloc:", NULL, &ops, ZSMALLOC_MAGIC); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim53100.00%1100.00%
Total53100.00%1100.00%

static struct file_system_type zsmalloc_fs = { .name = "zsmalloc", .mount = zs_mount, .kill_sb = kill_anon_super, };
static int zsmalloc_mount(void) { int ret = 0; zsmalloc_mnt = kern_mount(&zsmalloc_fs); if (IS_ERR(zsmalloc_mnt)) ret = PTR_ERR(zsmalloc_mnt); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim38100.00%1100.00%
Total38100.00%1100.00%


static void zsmalloc_unmount(void) { kern_unmount(zsmalloc_mnt); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim13100.00%1100.00%
Total13100.00%1100.00%


static void migrate_lock_init(struct zspage *zspage) { rwlock_init(&zspage->lock); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim19100.00%1100.00%
Total19100.00%1100.00%


static void migrate_read_lock(struct zspage *zspage) { read_lock(&zspage->lock); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim19100.00%1100.00%
Total19100.00%1100.00%


static void migrate_read_unlock(struct zspage *zspage) { read_unlock(&zspage->lock); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim19100.00%1100.00%
Total19100.00%1100.00%


static void migrate_write_lock(struct zspage *zspage) { write_lock(&zspage->lock); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim19100.00%1100.00%
Total19100.00%1100.00%


static void migrate_write_unlock(struct zspage *zspage) { write_unlock(&zspage->lock); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim19100.00%1100.00%
Total19100.00%1100.00%

/* Number of isolated subpage for *page migration* in this zspage */
static void inc_zspage_isolation(struct zspage *zspage) { zspage->isolated++; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim16100.00%1100.00%
Total16100.00%1100.00%


static void dec_zspage_isolation(struct zspage *zspage) { zspage->isolated--; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim16100.00%1100.00%
Total16100.00%1100.00%


static void replace_sub_page(struct size_class *class, struct zspage *zspage, struct page *newpage, struct page *oldpage) { struct page *page; struct page *pages[ZS_MAX_PAGES_PER_ZSPAGE] = {NULL, }; int idx = 0; page = get_first_page(zspage); do { if (page == oldpage) pages[idx] = newpage; else pages[idx] = page; idx++; } while ((page = get_next_page(page)) != NULL); create_page_chain(class, zspage, pages); set_first_obj_offset(newpage, get_first_obj_offset(oldpage)); if (unlikely(PageHugeObject(oldpage))) newpage->index = oldpage->index; __SetPageMovable(newpage, page_mapping(oldpage)); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim143100.00%1100.00%
Total143100.00%1100.00%


bool zs_page_isolate(struct page *page, isolate_mode_t mode) { struct zs_pool *pool; struct size_class *class; int class_idx; enum fullness_group fullness; struct zspage *zspage; struct address_space *mapping; /* * Page is locked so zspage couldn't be destroyed. For detail, look at * lock_zspage in free_zspage. */ VM_BUG_ON_PAGE(!PageMovable(page), page); VM_BUG_ON_PAGE(PageIsolated(page), page); zspage = get_zspage(page); /* * Without class lock, fullness could be stale while class_idx is okay * because class_idx is constant unless page is freed so we should get * fullness again under class lock. */ get_zspage_mapping(zspage, &class_idx, &fullness); mapping = page_mapping(page); pool = mapping->private_data; class = pool->size_class[class_idx]; spin_lock(&class->lock); if (get_zspage_inuse(zspage) == 0) { spin_unlock(&class->lock); return false; } /* zspage is isolated for object migration */ if (list_empty(&zspage->list) && !is_zspage_isolated(zspage)) { spin_unlock(&class->lock); return false; } /* * If this is first time isolation for the zspage, isolate zspage from * size_class to prevent further object allocation from the zspage. */ if (!list_empty(&zspage->list) && !is_zspage_isolated(zspage)) { get_zspage_mapping(zspage, &class_idx, &fullness); remove_zspage(class, zspage, fullness); } inc_zspage_isolation(zspage); spin_unlock(&class->lock); return true; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim219100.00%1100.00%
Total219100.00%1100.00%


int zs_page_migrate(struct address_space *mapping, struct page *newpage, struct page *page, enum migrate_mode mode) { struct zs_pool *pool; struct size_class *class; int class_idx; enum fullness_group fullness; struct zspage *zspage; struct page *dummy; void *s_addr, *d_addr, *addr; int offset, pos; unsigned long handle, head; unsigned long old_obj, new_obj; unsigned int obj_idx; int ret = -EAGAIN; VM_BUG_ON_PAGE(!PageMovable(page), page); VM_BUG_ON_PAGE(!PageIsolated(page), page); zspage = get_zspage(page); /* Concurrent compactor cannot migrate any subpage in zspage */ migrate_write_lock(zspage); get_zspage_mapping(zspage, &class_idx, &fullness); pool = mapping->private_data; class = pool->size_class[class_idx]; offset = get_first_obj_offset(page); spin_lock(&class->lock); if (!get_zspage_inuse(zspage)) { ret = -EBUSY; goto unlock_class; } pos = offset; s_addr = kmap_atomic(page); while (pos < PAGE_SIZE) { head = obj_to_head(page, s_addr + pos); if (head & OBJ_ALLOCATED_TAG) { handle = head & ~OBJ_ALLOCATED_TAG; if (!trypin_tag(handle)) goto unpin_objects; } pos += class->size; } /* * Here, any user cannot access all objects in the zspage so let's move. */ d_addr = kmap_atomic(newpage); memcpy(d_addr, s_addr, PAGE_SIZE); kunmap_atomic(d_addr); for (addr = s_addr + offset; addr < s_addr + pos; addr += class->size) { head = obj_to_head(page, addr); if (head & OBJ_ALLOCATED_TAG) { handle = head & ~OBJ_ALLOCATED_TAG; if (!testpin_tag(handle)) BUG(); old_obj = handle_to_obj(handle); obj_to_location(old_obj, &dummy, &obj_idx); new_obj = (unsigned long)location_to_obj(newpage, obj_idx); new_obj |= BIT(HANDLE_PIN_BIT); record_obj(handle, new_obj); } } replace_sub_page(class, zspage, newpage, page); get_page(newpage); dec_zspage_isolation(zspage); /* * Page migration is done so let's putback isolated zspage to * the list if @page is final isolated subpage in the zspage. */ if (!is_zspage_isolated(zspage)) putback_zspage(class, zspage); reset_page(page); put_page(page); page = newpage; ret = MIGRATEPAGE_SUCCESS; unpin_objects: for (addr = s_addr + offset; addr < s_addr + pos; addr += class->size) { head = obj_to_head(page, addr); if (head & OBJ_ALLOCATED_TAG) { handle = head & ~OBJ_ALLOCATED_TAG; if (!testpin_tag(handle)) BUG(); unpin_tag(handle); } } kunmap_atomic(s_addr); unlock_class: spin_unlock(&class->lock); migrate_write_unlock(zspage); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim510100.00%2100.00%
Total510100.00%2100.00%


void zs_page_putback(struct page *page) { struct zs_pool *pool; struct size_class *class; int class_idx; enum fullness_group fg; struct address_space *mapping; struct zspage *zspage; VM_BUG_ON_PAGE(!PageMovable(page), page); VM_BUG_ON_PAGE(!PageIsolated(page), page); zspage = get_zspage(page); get_zspage_mapping(zspage, &class_idx, &fg); mapping = page_mapping(page); pool = mapping->private_data; class = pool->size_class[class_idx]; spin_lock(&class->lock); dec_zspage_isolation(zspage); if (!is_zspage_isolated(zspage)) { fg = putback_zspage(class, zspage); /* * Due to page_lock, we cannot free zspage immediately * so let's defer. */ if (fg == ZS_EMPTY) schedule_work(&pool->free_work); } spin_unlock(&class->lock); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim154100.00%1100.00%
Total154100.00%1100.00%

const struct address_space_operations zsmalloc_aops = { .isolate_page = zs_page_isolate, .migratepage = zs_page_migrate, .putback_page = zs_page_putback, };
static int zs_register_migration(struct zs_pool *pool) { pool->inode = alloc_anon_inode(zsmalloc_mnt->mnt_sb); if (IS_ERR(pool->inode)) { pool->inode = NULL; return 1; } pool->inode->i_mapping->private_data = pool; pool->inode->i_mapping->a_ops = &zsmalloc_aops; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim66100.00%1100.00%
Total66100.00%1100.00%


static void zs_unregister_migration(struct zs_pool *pool) { flush_work(&pool->free_work); iput(pool->inode); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim26100.00%1100.00%
Total26100.00%1100.00%

/* * Caller should hold page_lock of all pages in the zspage * In here, we cannot use zspage meta data. */
static void async_free_zspage(struct work_struct *work) { int i; struct size_class *class; unsigned int class_idx; enum fullness_group fullness; struct zspage *zspage, *tmp; LIST_HEAD(free_pages); struct zs_pool *pool = container_of(work, struct zs_pool, free_work); for (i = 0; i < zs_size_classes; i++) { class = pool->size_class[i]; if (class->index != i) continue; spin_lock(&class->lock); list_splice_init(&class->fullness_list[ZS_EMPTY], &free_pages); spin_unlock(&class->lock); } list_for_each_entry_safe(zspage, tmp, &free_pages, list) { list_del(&zspage->list); lock_zspage(zspage); get_zspage_mapping(zspage, &class_idx, &fullness); VM_BUG_ON(fullness != ZS_EMPTY); class = pool->size_class[class_idx]; spin_lock(&class->lock); __free_zspage(pool, pool->size_class[class_idx], zspage); spin_unlock(&class->lock); } }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim200100.00%3100.00%
Total200100.00%3100.00%

;
static void kick_deferred_free(struct zs_pool *pool) { schedule_work(&pool->free_work); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim19100.00%2100.00%
Total19100.00%2100.00%


static void init_deferred_free(struct zs_pool *pool) { INIT_WORK(&pool->free_work, async_free_zspage); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim21100.00%2100.00%
Total21100.00%2100.00%


static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage) { struct page *page = get_first_page(zspage); do { WARN_ON(!trylock_page(page)); __SetPageMovable(page, pool->inode->i_mapping); unlock_page(page); } while ((page = get_next_page(page)) != NULL); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim68100.00%4100.00%
Total68100.00%4100.00%

#endif /* * * Based on the number of unused allocated objects calculate * and return the number of pages that we can free. */
static unsigned long zs_can_compact(struct size_class *class) { unsigned long obj_wasted; unsigned long obj_allocated = zs_stat_get(class, OBJ_ALLOCATED); unsigned long obj_used = zs_stat_get(class, OBJ_USED); if (obj_allocated <= obj_used) return 0; obj_wasted = obj_allocated - obj_used; obj_wasted /= class->objs_per_zspage; return obj_wasted * class->pages_per_zspage; }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Senozhatsky6496.97%250.00%
MinChan Kim11.52%125.00%
Ganesh Mahendran11.52%125.00%
Total66100.00%4100.00%


static void __zs_compact(struct zs_pool *pool, struct size_class *class) { struct zs_compact_control cc; struct zspage *src_zspage; struct zspage *dst_zspage = NULL; spin_lock(&class->lock); while ((src_zspage = isolate_zspage(class, true))) { if (!zs_can_compact(class)) break; cc.obj_idx = 0; cc.s_page = get_first_page(src_zspage); while ((dst_zspage = isolate_zspage(class, false))) { cc.d_page = get_first_page(dst_zspage); /* * If there is no more space in dst_page, resched * and see if anyone had allocated another zspage. */ if (!migrate_zspage(pool, class, &cc)) break; putback_zspage(class, dst_zspage); } /* Stop if we couldn't find slot */ if (dst_zspage == NULL) break; putback_zspage(class, dst_zspage); if (putback_zspage(class, src_zspage) == ZS_EMPTY) { free_zspage(pool, class, src_zspage); pool->stats.pages_compacted += class->pages_per_zspage; } spin_unlock(&class->lock); cond_resched(); spin_lock(&class->lock); } if (src_zspage) putback_zspage(class, src_zspage); spin_unlock(&class->lock); }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim18588.10%550.00%
Sergey Senozhatsky2411.43%440.00%
Ganesh Mahendran10.48%110.00%
Total210100.00%10100.00%


unsigned long zs_compact(struct zs_pool *pool) { int i; struct size_class *class; for (i = zs_size_classes - 1; i >= 0; i--) { class = pool->size_class[i]; if (!class) continue; if (class->index != i) continue; __zs_compact(pool, class); } return pool->stats.pages_compacted; }

Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim6993.24%133.33%
Sergey Senozhatsky56.76%266.67%
Total74100.00%3100.00%

EXPORT_SYMBOL_GPL(zs_compact);
void zs_pool_stats(struct zs_pool *pool, struct zs_pool_stats *stats) { memcpy(stats, &pool->stats, sizeof(struct zs_pool_stats)); }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Senozhatsky31100.00%1100.00%
Total31100.00%1100.00%

EXPORT_SYMBOL_GPL(zs_pool_stats);
static unsigned long zs_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc) { unsigned long pages_freed; struct zs_pool *pool = container_of(shrinker, struct zs_pool, shrinker); pages_freed = pool->stats.pages_compacted; /* * Compact classes and calculate compaction delta. * Can run concurrently with a manually triggered * (by user) compaction. */ pages_freed = zs_compact(pool) - pages_freed; return pages_freed ? pages_freed : SHRINK_STOP; }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Senozhatsky61100.00%1100.00%
Total61100.00%1100.00%


static unsigned long zs_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc) { int i; struct size_class *class; unsigned long pages_to_free = 0; struct zs_pool *pool = container_of(shrinker, struct zs_pool, shrinker); for (i = zs_size_classes - 1; i >= 0; i--) { class = pool->size_class[i]; if (!class) continue; if (class->index != i) continue; pages_to_free += zs_can_compact(class); } return pages_to_free; }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Senozhatsky97100.00%1100.00%
Total97100.00%1100.00%


static void zs_unregister_shrinker(struct zs_pool *pool) { if (pool->shrinker_enabled) { unregister_shrinker(&pool->shrinker); pool->shrinker_enabled = false; } }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Senozhatsky33100.00%1100.00%
Total33100.00%1100.00%


static int zs_register_shrinker(struct zs_pool *pool) { pool->shrinker.scan_objects = zs_shrinker_scan; pool->shrinker.count_objects = zs_shrinker_count; pool->shrinker.batch = 0; pool->shrinker.seeks = DEFAULT_SEEKS; return register_shrinker(&pool->shrinker); }

Contributors

PersonTokensPropCommitsCommitProp
Sergey Senozhatsky52100.00%1100.00%
Total52100.00%1100.00%

/** * zs_create_pool - Creates an allocation pool to work from. * @name: pool name to be created * * This function must be called before anything when using * the zsmalloc allocator. * * On success, a pointer to the newly created pool is returned, * otherwise NULL. */
struct zs_pool *zs_create_pool(const char *name) { int i; struct zs_pool *pool; struct size_class *prev_class = NULL; pool = kzalloc(sizeof(*pool), GFP_KERNEL); if (!pool) return NULL; init_deferred_free(pool); pool->size_class = kcalloc(zs_size_classes, sizeof(struct size_class *), GFP_KERNEL); if (!pool->size_class) { kfree(pool); return NULL; } pool->name = kstrdup(name, GFP_KERNEL); if (!pool->name) goto err; if (create_cache(pool)) goto err; /* * Iterate reversely, because, size of size_class that we want to use * for merging should be larger or equal to current size. */ for (i = zs_size_classes - 1; i >= 0; i--) { int size; int pages_per_zspage; int objs_per_zspage; struct size_class *class; int fullness = 0; size = ZS_MIN_ALLOC_SIZE + i * ZS_SIZE_CLASS_DELTA; if (size > ZS_MAX_ALLOC_SIZE) size = ZS_MAX_ALLOC_SIZE; pages_per_zspage = get_pages_per_zspage(size); objs_per_zspage = pages_per_zspage * PAGE_SIZE / size; /* * size_class is used for normal zsmalloc operation such * as alloc/free for that size. Although it is natural that we * have one size_class for each size, there is a chance that we * can get more memory utilization if we use one size_class for * many different sizes whose size_class have same * characteristics. So, we makes size_class point to * previous size_class if possible. */ if (prev_class) { if (can_merge(prev_class, pages_per_zspage, objs_per_zspage)) { pool->size_class[i] = prev_class; continue; } } class = kzalloc(sizeof(struct size_class), GFP_KERNEL); if (!class) goto err; class->size = size; class->index = i; class->pages_per_zspage = pages_per_zspage; class->objs_per_zspage = objs_per_zspage; spin_lock_init(&class->lock); pool->size_class[i] = class; for (fullness = ZS_EMPTY; fullness < NR_ZS_FULLNESS; fullness++) INIT_LIST_HEAD(&class->fullness_list[fullness]); prev_class = class; } /* debug only, don't abort if it fails */ zs_pool_stat_create(pool, name); if (zs_register_migration(pool)) goto err; /* * Not critical, we still can use the pool * and user can trigger compaction manually. */ if (zs_register_shrinker(pool) == 0) pool->shrinker_enabled = true; return pool; err: zs_destroy_pool(pool); return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
Ganesh Mahendran20156.46%422.22%
MinChan Kim7621.35%527.78%
Nitin Gupta4412.36%15.56%
Sergey Senozhatsky174.78%211.11%
Seth Jennings154.21%422.22%
Dan Streetman20.56%15.56%
Xishi Qiu10.28%15.56%
Total356100.00%18100.00%

EXPORT_SYMBOL_GPL(zs_create_pool);
void zs_destroy_pool(struct zs_pool *pool) { int i; zs_unregister_shrinker(pool); zs_unregister_migration(pool); zs_pool_stat_destroy(pool); for (i = 0; i < zs_size_classes; i++) { int fg; struct size_class *class = pool->size_class[i]; if (!class) continue; if (class->index != i) continue; for (fg = ZS_EMPTY; fg < NR_ZS_FULLNESS; fg++) { if (!list_empty(&class->fullness_list[fg])) { pr_info("Freeing non-empty class with size %db, fullness group %d\n", class->size, fg); } } kfree(class); } destroy_cache(pool); kfree(pool->size_class); kfree(pool->name); kfree(pool); }

Contributors

PersonTokensPropCommitsCommitProp
Ganesh Mahendran7753.47%225.00%
Nitin Gupta2920.14%112.50%
MinChan Kim1812.50%337.50%
Seth Jennings1510.42%112.50%
Sergey Senozhatsky53.47%112.50%
Total144100.00%8100.00%

EXPORT_SYMBOL_GPL(zs_destroy_pool);
static int __init zs_init(void) { int ret; ret = zsmalloc_mount(); if (ret) goto out; ret = cpuhp_setup_state(CPUHP_MM_ZS_PREPARE, "mm/zsmalloc:prepare", zs_cpu_prepare, zs_cpu_dead); if (ret) goto hp_setup_fail; init_zs_size_classes(); #ifdef CONFIG_ZPOOL zpool_register_driver(&zs_zpool_driver); #endif zs_stat_init(); return 0; hp_setup_fail: zsmalloc_unmount(); out: return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Ganesh Mahendran3344.59%233.33%
MinChan Kim2432.43%233.33%
Sebastian Andrzej Siewior1216.22%116.67%
Nitin Gupta56.76%116.67%
Total74100.00%6100.00%


static void __exit zs_exit(void) { #ifdef CONFIG_ZPOOL zpool_unregister_driver(&zs_zpool_driver); #endif zsmalloc_unmount(); cpuhp_remove_state(CPUHP_MM_ZS_PREPARE); zs_stat_exit(); }

Contributors

PersonTokensPropCommitsCommitProp
Ganesh Mahendran2167.74%240.00%
Sebastian Andrzej Siewior412.90%120.00%
Nitin Gupta39.68%120.00%
MinChan Kim39.68%120.00%
Total31100.00%5100.00%

module_init(zs_init); module_exit(zs_exit); MODULE_LICENSE("Dual BSD/GPL"); MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>");

Overall Contributors

PersonTokensPropCommitsCommitProp
MinChan Kim701070.12%2934.52%
Ganesh Mahendran9289.28%1214.29%
Nitin Gupta7737.73%33.57%
Sergey Senozhatsky5075.07%1416.67%
Dan Streetman3443.44%44.76%
Seth Jennings2912.91%78.33%
JoonSoo Kim500.50%11.19%
Sebastian Andrzej Siewior350.35%11.19%
Ben Hutchings200.20%11.19%
Junil Lee130.13%11.19%
Kirill A. Shutemov70.07%11.19%
Kees Cook50.05%11.19%
Ingo Molnar30.03%11.19%
Srivatsa S. Bhat20.02%11.19%
Sunghan Suh20.02%11.19%
Yisheng Xie20.02%11.19%
Krzysztof Kozlowski10.01%11.19%
Weijie Yang10.01%11.19%
Xishi Qiu10.01%11.19%
Yinghao Xie10.01%11.19%
Wang Sheng-Hui10.01%11.19%
Total9997100.00%84100.00%
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