blob: 61cb05dc950caf394dbf375b5b7084a193cbaddb [file] [log] [blame]
Nitin Gupta61989a82012-01-09 16:51:56 -06001/*
2 * zsmalloc memory allocator
3 *
4 * Copyright (C) 2011 Nitin Gupta
Minchan Kim31fc00b2014-01-30 15:45:55 -08005 * Copyright (C) 2012, 2013 Minchan Kim
Nitin Gupta61989a82012-01-09 16:51:56 -06006 *
7 * This code is released using a dual license strategy: BSD/GPL
8 * You can choose the license that better fits your requirements.
9 *
10 * Released under the terms of 3-clause BSD License
11 * Released under the terms of GNU General Public License Version 2.0
12 */
13
Nitin Gupta2db51da2012-06-09 17:41:14 -070014/*
Nitin Gupta2db51da2012-06-09 17:41:14 -070015 * Following is how we use various fields and flags of underlying
16 * struct page(s) to form a zspage.
17 *
18 * Usage of struct page fields:
Minchan Kim37836892016-07-26 15:23:23 -070019 * page->private: points to zspage
Minchan Kim48b48002016-07-26 15:23:31 -070020 * page->freelist(index): links together all component pages of a zspage
21 * For the huge page, this is always 0, so we use this field
22 * to store handle.
Ganesh Mahendranfd854462016-07-28 15:47:54 -070023 * page->units: first object offset in a subpage of zspage
Nitin Gupta2db51da2012-06-09 17:41:14 -070024 *
25 * Usage of struct page flags:
26 * PG_private: identifies the first component page
Xishi Qiu399d8ee2017-02-22 15:45:01 -080027 * PG_owner_priv_1: identifies the huge component page
Nitin Gupta2db51da2012-06-09 17:41:14 -070028 *
29 */
30
Dan Streetman4abaac92016-05-26 15:16:27 -070031#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
32
Nitin Gupta61989a82012-01-09 16:51:56 -060033#include <linux/module.h>
34#include <linux/kernel.h>
Minchan Kim312fcae2015-04-15 16:15:30 -070035#include <linux/sched.h>
Ingo Molnar50d34392017-02-05 16:03:58 +010036#include <linux/magic.h>
Nitin Gupta61989a82012-01-09 16:51:56 -060037#include <linux/bitops.h>
38#include <linux/errno.h>
39#include <linux/highmem.h>
Nitin Gupta61989a82012-01-09 16:51:56 -060040#include <linux/string.h>
41#include <linux/slab.h>
42#include <asm/tlbflush.h>
43#include <asm/pgtable.h>
44#include <linux/cpumask.h>
45#include <linux/cpu.h>
Seth Jennings0cbb6132012-02-13 08:47:49 -060046#include <linux/vmalloc.h>
Sergey Senozhatsky759b26b2015-11-06 16:29:29 -080047#include <linux/preempt.h>
Seth Jennings0959c632012-08-08 15:12:17 +090048#include <linux/spinlock.h>
Aliaksei Karaliou93144ca2018-01-31 16:18:40 -080049#include <linux/shrinker.h>
Seth Jennings0959c632012-08-08 15:12:17 +090050#include <linux/types.h>
Ganesh Mahendran0f050d92015-02-12 15:00:54 -080051#include <linux/debugfs.h>
Minchan Kimbcf16472014-01-30 15:45:50 -080052#include <linux/zsmalloc.h>
Dan Streetmanc7957792014-08-06 16:08:38 -070053#include <linux/zpool.h>
Minchan Kim48b48002016-07-26 15:23:31 -070054#include <linux/mount.h>
Minchan Kimdd4123f2016-07-26 15:26:50 -070055#include <linux/migrate.h>
Minchan Kim48b48002016-07-26 15:23:31 -070056#include <linux/pagemap.h>
Sergey Senozhatskycdc346b2018-01-04 16:18:02 -080057#include <linux/fs.h>
Minchan Kim48b48002016-07-26 15:23:31 -070058
59#define ZSPAGE_MAGIC 0x58
Seth Jennings0959c632012-08-08 15:12:17 +090060
61/*
62 * This must be power of 2 and greater than of equal to sizeof(link_free).
63 * These two conditions ensure that any 'struct link_free' itself doesn't
64 * span more than 1 page which avoids complex case of mapping 2 pages simply
65 * to restore link_free pointer values.
66 */
67#define ZS_ALIGN 8
68
69/*
70 * A single 'zspage' is composed of up to 2^N discontiguous 0-order (single)
71 * pages. ZS_MAX_ZSPAGE_ORDER defines upper limit on N.
72 */
73#define ZS_MAX_ZSPAGE_ORDER 2
74#define ZS_MAX_PAGES_PER_ZSPAGE (_AC(1, UL) << ZS_MAX_ZSPAGE_ORDER)
75
Minchan Kim2e40e162015-04-15 16:15:23 -070076#define ZS_HANDLE_SIZE (sizeof(unsigned long))
77
Seth Jennings0959c632012-08-08 15:12:17 +090078/*
79 * Object location (<PFN>, <obj_idx>) is encoded as
Nitin Cuptac3e3e88a2013-12-11 11:04:37 +090080 * as single (unsigned long) handle value.
Seth Jennings0959c632012-08-08 15:12:17 +090081 *
Minchan Kimbfd093f2016-07-26 15:23:28 -070082 * Note that object index <obj_idx> starts from 0.
Seth Jennings0959c632012-08-08 15:12:17 +090083 *
84 * This is made more complicated by various memory models and PAE.
85 */
86
Kirill A. Shutemov02390b82018-02-14 14:16:49 +030087#ifndef MAX_POSSIBLE_PHYSMEM_BITS
88#ifdef MAX_PHYSMEM_BITS
89#define MAX_POSSIBLE_PHYSMEM_BITS MAX_PHYSMEM_BITS
90#else
Seth Jennings0959c632012-08-08 15:12:17 +090091/*
92 * If this definition of MAX_PHYSMEM_BITS is used, OBJ_INDEX_BITS will just
93 * be PAGE_SHIFT
94 */
Kirill A. Shutemov02390b82018-02-14 14:16:49 +030095#define MAX_POSSIBLE_PHYSMEM_BITS BITS_PER_LONG
Seth Jennings0959c632012-08-08 15:12:17 +090096#endif
97#endif
Kirill A. Shutemov02390b82018-02-14 14:16:49 +030098
99#define _PFN_BITS (MAX_POSSIBLE_PHYSMEM_BITS - PAGE_SHIFT)
Minchan Kim312fcae2015-04-15 16:15:30 -0700100
101/*
102 * Memory for allocating for handle keeps object position by
103 * encoding <page, obj_idx> and the encoded value has a room
104 * in least bit(ie, look at obj_to_location).
105 * We use the bit to synchronize between object access by
106 * user and migration.
107 */
108#define HANDLE_PIN_BIT 0
109
110/*
111 * Head in allocated object should have OBJ_ALLOCATED_TAG
112 * to identify the object was allocated or not.
113 * It's okay to add the status bit in the least bit because
114 * header keeps handle which is 4byte-aligned address so we
115 * have room for two bit at least.
116 */
117#define OBJ_ALLOCATED_TAG 1
118#define OBJ_TAG_BITS 1
119#define OBJ_INDEX_BITS (BITS_PER_LONG - _PFN_BITS - OBJ_TAG_BITS)
Seth Jennings0959c632012-08-08 15:12:17 +0900120#define OBJ_INDEX_MASK ((_AC(1, UL) << OBJ_INDEX_BITS) - 1)
121
Jerome Marchandcf8e0fed2017-07-10 15:50:18 -0700122#define FULLNESS_BITS 2
123#define CLASS_BITS 8
124#define ISOLATED_BITS 3
125#define MAGIC_VAL_BITS 8
126
Seth Jennings0959c632012-08-08 15:12:17 +0900127#define MAX(a, b) ((a) >= (b) ? (a) : (b))
128/* ZS_MIN_ALLOC_SIZE must be multiple of ZS_ALIGN */
129#define ZS_MIN_ALLOC_SIZE \
130 MAX(32, (ZS_MAX_PAGES_PER_ZSPAGE << PAGE_SHIFT >> OBJ_INDEX_BITS))
Minchan Kim2e40e162015-04-15 16:15:23 -0700131/* each chunk includes extra space to keep handle */
Minchan Kim7b60a682015-04-15 16:15:39 -0700132#define ZS_MAX_ALLOC_SIZE PAGE_SIZE
Seth Jennings0959c632012-08-08 15:12:17 +0900133
134/*
Weijie Yang7eb52512014-06-04 16:11:08 -0700135 * On systems with 4K page size, this gives 255 size classes! There is a
Seth Jennings0959c632012-08-08 15:12:17 +0900136 * trader-off here:
137 * - Large number of size classes is potentially wasteful as free page are
138 * spread across these classes
139 * - Small number of size classes causes large internal fragmentation
140 * - Probably its better to use specific size classes (empirically
141 * determined). NOTE: all those class sizes must be set as multiple of
142 * ZS_ALIGN to make sure link_free itself never has to span 2 pages.
143 *
144 * ZS_MIN_ALLOC_SIZE and ZS_SIZE_CLASS_DELTA must be multiple of ZS_ALIGN
145 * (reason above)
146 */
Minchan Kim37836892016-07-26 15:23:23 -0700147#define ZS_SIZE_CLASS_DELTA (PAGE_SIZE >> CLASS_BITS)
Jerome Marchandcf8e0fed2017-07-10 15:50:18 -0700148#define ZS_SIZE_CLASSES (DIV_ROUND_UP(ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE, \
149 ZS_SIZE_CLASS_DELTA) + 1)
Seth Jennings0959c632012-08-08 15:12:17 +0900150
Seth Jennings0959c632012-08-08 15:12:17 +0900151enum fullness_group {
Seth Jennings0959c632012-08-08 15:12:17 +0900152 ZS_EMPTY,
Minchan Kim48b48002016-07-26 15:23:31 -0700153 ZS_ALMOST_EMPTY,
154 ZS_ALMOST_FULL,
155 ZS_FULL,
156 NR_ZS_FULLNESS,
Seth Jennings0959c632012-08-08 15:12:17 +0900157};
158
Ganesh Mahendran0f050d92015-02-12 15:00:54 -0800159enum zs_stat_type {
Minchan Kim48b48002016-07-26 15:23:31 -0700160 CLASS_EMPTY,
161 CLASS_ALMOST_EMPTY,
162 CLASS_ALMOST_FULL,
163 CLASS_FULL,
Ganesh Mahendran0f050d92015-02-12 15:00:54 -0800164 OBJ_ALLOCATED,
165 OBJ_USED,
Minchan Kim48b48002016-07-26 15:23:31 -0700166 NR_ZS_STAT_TYPE,
Ganesh Mahendran0f050d92015-02-12 15:00:54 -0800167};
168
Ganesh Mahendran0f050d92015-02-12 15:00:54 -0800169struct zs_size_stat {
170 unsigned long objs[NR_ZS_STAT_TYPE];
171};
172
Sergey Senozhatsky57244592015-09-08 15:04:27 -0700173#ifdef CONFIG_ZSMALLOC_STAT
174static struct dentry *zs_stat_root;
Ganesh Mahendran0f050d92015-02-12 15:00:54 -0800175#endif
176
Minchan Kim48b48002016-07-26 15:23:31 -0700177#ifdef CONFIG_COMPACTION
178static struct vfsmount *zsmalloc_mnt;
179#endif
180
Seth Jennings0959c632012-08-08 15:12:17 +0900181/*
182 * We assign a page to ZS_ALMOST_EMPTY fullness group when:
183 * n <= N / f, where
184 * n = number of allocated objects
185 * N = total number of objects zspage can store
Wang Sheng-Hui6dd97372014-10-09 15:29:59 -0700186 * f = fullness_threshold_frac
Seth Jennings0959c632012-08-08 15:12:17 +0900187 *
188 * Similarly, we assign zspage to:
189 * ZS_ALMOST_FULL when n > N / f
190 * ZS_EMPTY when n == 0
191 * ZS_FULL when n == N
192 *
193 * (see: fix_fullness_group())
194 */
195static const int fullness_threshold_frac = 4;
Sergey Senozhatsky010b4952018-04-05 16:24:43 -0700196static size_t huge_class_size;
Seth Jennings0959c632012-08-08 15:12:17 +0900197
198struct size_class {
Sergey Senozhatsky57244592015-09-08 15:04:27 -0700199 spinlock_t lock;
Minchan Kim48b48002016-07-26 15:23:31 -0700200 struct list_head fullness_list[NR_ZS_FULLNESS];
Seth Jennings0959c632012-08-08 15:12:17 +0900201 /*
202 * Size of objects stored in this class. Must be multiple
203 * of ZS_ALIGN.
204 */
205 int size;
Minchan Kim1fc6e272016-07-26 15:23:11 -0700206 int objs_per_zspage;
Weijie Yang7dfa4612016-01-14 15:22:40 -0800207 /* Number of PAGE_SIZE sized pages to combine to form a 'zspage' */
208 int pages_per_zspage;
Minchan Kim48b48002016-07-26 15:23:31 -0700209
210 unsigned int index;
211 struct zs_size_stat stats;
Seth Jennings0959c632012-08-08 15:12:17 +0900212};
213
Minchan Kim48b48002016-07-26 15:23:31 -0700214/* huge object: pages_per_zspage == 1 && maxobj_per_zspage == 1 */
215static void SetPageHugeObject(struct page *page)
216{
217 SetPageOwnerPriv1(page);
218}
219
220static void ClearPageHugeObject(struct page *page)
221{
222 ClearPageOwnerPriv1(page);
223}
224
225static int PageHugeObject(struct page *page)
226{
227 return PageOwnerPriv1(page);
228}
229
Seth Jennings0959c632012-08-08 15:12:17 +0900230/*
231 * Placed within free objects to form a singly linked list.
Minchan Kim37836892016-07-26 15:23:23 -0700232 * For every zspage, zspage->freeobj gives head of this list.
Seth Jennings0959c632012-08-08 15:12:17 +0900233 *
234 * This must be power of 2 and less than or equal to ZS_ALIGN
235 */
236struct link_free {
Minchan Kim2e40e162015-04-15 16:15:23 -0700237 union {
238 /*
Minchan Kimbfd093f2016-07-26 15:23:28 -0700239 * Free object index;
Minchan Kim2e40e162015-04-15 16:15:23 -0700240 * It's valid for non-allocated object
241 */
Minchan Kimbfd093f2016-07-26 15:23:28 -0700242 unsigned long next;
Minchan Kim2e40e162015-04-15 16:15:23 -0700243 /*
244 * Handle of allocated object.
245 */
246 unsigned long handle;
247 };
Seth Jennings0959c632012-08-08 15:12:17 +0900248};
249
250struct zs_pool {
Sergey SENOZHATSKY6f3526d2015-11-06 16:29:21 -0800251 const char *name;
Ganesh Mahendran0f050d92015-02-12 15:00:54 -0800252
Jerome Marchandcf8e0fed2017-07-10 15:50:18 -0700253 struct size_class *size_class[ZS_SIZE_CLASSES];
Minchan Kim2e40e162015-04-15 16:15:23 -0700254 struct kmem_cache *handle_cachep;
Minchan Kim37836892016-07-26 15:23:23 -0700255 struct kmem_cache *zspage_cachep;
Seth Jennings0959c632012-08-08 15:12:17 +0900256
Minchan Kim13de8932014-10-09 15:29:48 -0700257 atomic_long_t pages_allocated;
Ganesh Mahendran0f050d92015-02-12 15:00:54 -0800258
Sergey Senozhatsky7d3f3932015-09-08 15:04:35 -0700259 struct zs_pool_stats stats;
Sergey Senozhatskyab9d3062015-09-08 15:04:41 -0700260
261 /* Compact classes */
262 struct shrinker shrinker;
Aliaksei Karaliou93144ca2018-01-31 16:18:40 -0800263
Ganesh Mahendran0f050d92015-02-12 15:00:54 -0800264#ifdef CONFIG_ZSMALLOC_STAT
265 struct dentry *stat_dentry;
266#endif
Minchan Kim48b48002016-07-26 15:23:31 -0700267#ifdef CONFIG_COMPACTION
268 struct inode *inode;
269 struct work_struct free_work;
270#endif
Seth Jennings0959c632012-08-08 15:12:17 +0900271};
Nitin Gupta61989a82012-01-09 16:51:56 -0600272
Minchan Kim37836892016-07-26 15:23:23 -0700273struct zspage {
274 struct {
275 unsigned int fullness:FULLNESS_BITS;
Minchan Kim85d492f2017-04-13 14:56:40 -0700276 unsigned int class:CLASS_BITS + 1;
Minchan Kim48b48002016-07-26 15:23:31 -0700277 unsigned int isolated:ISOLATED_BITS;
278 unsigned int magic:MAGIC_VAL_BITS;
Minchan Kim37836892016-07-26 15:23:23 -0700279 };
280 unsigned int inuse;
Minchan Kimbfd093f2016-07-26 15:23:28 -0700281 unsigned int freeobj;
Minchan Kim37836892016-07-26 15:23:23 -0700282 struct page *first_page;
283 struct list_head list; /* fullness list */
Minchan Kim48b48002016-07-26 15:23:31 -0700284#ifdef CONFIG_COMPACTION
285 rwlock_t lock;
286#endif
Minchan Kim37836892016-07-26 15:23:23 -0700287};
Nitin Gupta61989a82012-01-09 16:51:56 -0600288
Seth Jenningsf5536462012-07-18 11:55:56 -0500289struct mapping_area {
Minchan Kim1b945ae2013-12-11 11:04:36 +0900290#ifdef CONFIG_PGTABLE_MAPPING
Seth Jenningsf5536462012-07-18 11:55:56 -0500291 struct vm_struct *vm; /* vm area for mapping object that span pages */
292#else
293 char *vm_buf; /* copy buffer for objects that span pages */
294#endif
295 char *vm_addr; /* address of kmap_atomic()'ed pages */
296 enum zs_mapmode vm_mm; /* mapping mode */
297};
298
Minchan Kim48b48002016-07-26 15:23:31 -0700299#ifdef CONFIG_COMPACTION
300static int zs_register_migration(struct zs_pool *pool);
301static void zs_unregister_migration(struct zs_pool *pool);
302static void migrate_lock_init(struct zspage *zspage);
303static void migrate_read_lock(struct zspage *zspage);
304static void migrate_read_unlock(struct zspage *zspage);
305static void kick_deferred_free(struct zs_pool *pool);
306static void init_deferred_free(struct zs_pool *pool);
307static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage);
308#else
309static int zsmalloc_mount(void) { return 0; }
310static void zsmalloc_unmount(void) {}
311static int zs_register_migration(struct zs_pool *pool) { return 0; }
312static void zs_unregister_migration(struct zs_pool *pool) {}
313static void migrate_lock_init(struct zspage *zspage) {}
314static void migrate_read_lock(struct zspage *zspage) {}
315static void migrate_read_unlock(struct zspage *zspage) {}
316static void kick_deferred_free(struct zs_pool *pool) {}
317static void init_deferred_free(struct zs_pool *pool) {}
318static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage) {}
319#endif
320
Minchan Kim37836892016-07-26 15:23:23 -0700321static int create_cache(struct zs_pool *pool)
Minchan Kim2e40e162015-04-15 16:15:23 -0700322{
323 pool->handle_cachep = kmem_cache_create("zs_handle", ZS_HANDLE_SIZE,
324 0, 0, NULL);
Minchan Kim37836892016-07-26 15:23:23 -0700325 if (!pool->handle_cachep)
326 return 1;
327
328 pool->zspage_cachep = kmem_cache_create("zspage", sizeof(struct zspage),
329 0, 0, NULL);
330 if (!pool->zspage_cachep) {
331 kmem_cache_destroy(pool->handle_cachep);
332 pool->handle_cachep = NULL;
333 return 1;
334 }
335
336 return 0;
Minchan Kim2e40e162015-04-15 16:15:23 -0700337}
338
Minchan Kim37836892016-07-26 15:23:23 -0700339static void destroy_cache(struct zs_pool *pool)
Minchan Kim2e40e162015-04-15 16:15:23 -0700340{
Sergey Senozhatskycd10add2015-09-08 15:04:55 -0700341 kmem_cache_destroy(pool->handle_cachep);
Minchan Kim37836892016-07-26 15:23:23 -0700342 kmem_cache_destroy(pool->zspage_cachep);
Minchan Kim2e40e162015-04-15 16:15:23 -0700343}
344
Minchan Kim37836892016-07-26 15:23:23 -0700345static unsigned long cache_alloc_handle(struct zs_pool *pool, gfp_t gfp)
Minchan Kim2e40e162015-04-15 16:15:23 -0700346{
347 return (unsigned long)kmem_cache_alloc(pool->handle_cachep,
Minchan Kim48b48002016-07-26 15:23:31 -0700348 gfp & ~(__GFP_HIGHMEM|__GFP_MOVABLE));
Minchan Kim2e40e162015-04-15 16:15:23 -0700349}
350
Minchan Kim37836892016-07-26 15:23:23 -0700351static void cache_free_handle(struct zs_pool *pool, unsigned long handle)
Minchan Kim2e40e162015-04-15 16:15:23 -0700352{
353 kmem_cache_free(pool->handle_cachep, (void *)handle);
354}
355
Minchan Kim37836892016-07-26 15:23:23 -0700356static struct zspage *cache_alloc_zspage(struct zs_pool *pool, gfp_t flags)
357{
Minchan Kim48b48002016-07-26 15:23:31 -0700358 return kmem_cache_alloc(pool->zspage_cachep,
359 flags & ~(__GFP_HIGHMEM|__GFP_MOVABLE));
Xishi Qiu399d8ee2017-02-22 15:45:01 -0800360}
Minchan Kim37836892016-07-26 15:23:23 -0700361
362static void cache_free_zspage(struct zs_pool *pool, struct zspage *zspage)
363{
364 kmem_cache_free(pool->zspage_cachep, zspage);
365}
366
Minchan Kim2e40e162015-04-15 16:15:23 -0700367static void record_obj(unsigned long handle, unsigned long obj)
368{
Junil Leec102f07c2016-01-20 14:58:18 -0800369 /*
370 * lsb of @obj represents handle lock while other bits
371 * represent object value the handle is pointing so
372 * updating shouldn't do store tearing.
373 */
374 WRITE_ONCE(*(unsigned long *)handle, obj);
Minchan Kim2e40e162015-04-15 16:15:23 -0700375}
376
Dan Streetmanc7957792014-08-06 16:08:38 -0700377/* zpool driver */
378
379#ifdef CONFIG_ZPOOL
380
Sergey SENOZHATSKY6f3526d2015-11-06 16:29:21 -0800381static void *zs_zpool_create(const char *name, gfp_t gfp,
Krzysztof Kozlowski78672772015-09-08 15:05:03 -0700382 const struct zpool_ops *zpool_ops,
Dan Streetman479305f2015-06-25 15:00:40 -0700383 struct zpool *zpool)
Dan Streetmanc7957792014-08-06 16:08:38 -0700384{
Sergey Senozhatskyd0d8da22016-05-20 16:59:48 -0700385 /*
386 * Ignore global gfp flags: zs_malloc() may be invoked from
387 * different contexts and its caller must provide a valid
388 * gfp mask.
389 */
390 return zs_create_pool(name);
Dan Streetmanc7957792014-08-06 16:08:38 -0700391}
392
393static void zs_zpool_destroy(void *pool)
394{
395 zs_destroy_pool(pool);
396}
397
398static int zs_zpool_malloc(void *pool, size_t size, gfp_t gfp,
399 unsigned long *handle)
400{
Sergey Senozhatskyd0d8da22016-05-20 16:59:48 -0700401 *handle = zs_malloc(pool, size, gfp);
Dan Streetmanc7957792014-08-06 16:08:38 -0700402 return *handle ? 0 : -1;
403}
404static void zs_zpool_free(void *pool, unsigned long handle)
405{
406 zs_free(pool, handle);
407}
408
Dan Streetmanc7957792014-08-06 16:08:38 -0700409static void *zs_zpool_map(void *pool, unsigned long handle,
410 enum zpool_mapmode mm)
411{
412 enum zs_mapmode zs_mm;
413
414 switch (mm) {
415 case ZPOOL_MM_RO:
416 zs_mm = ZS_MM_RO;
417 break;
418 case ZPOOL_MM_WO:
419 zs_mm = ZS_MM_WO;
420 break;
421 case ZPOOL_MM_RW: /* fallthru */
422 default:
423 zs_mm = ZS_MM_RW;
424 break;
425 }
426
427 return zs_map_object(pool, handle, zs_mm);
428}
429static void zs_zpool_unmap(void *pool, unsigned long handle)
430{
431 zs_unmap_object(pool, handle);
432}
433
434static u64 zs_zpool_total_size(void *pool)
435{
Minchan Kim722cdc12014-10-09 15:29:50 -0700436 return zs_get_total_pages(pool) << PAGE_SHIFT;
Dan Streetmanc7957792014-08-06 16:08:38 -0700437}
438
439static struct zpool_driver zs_zpool_driver = {
440 .type = "zsmalloc",
441 .owner = THIS_MODULE,
442 .create = zs_zpool_create,
443 .destroy = zs_zpool_destroy,
444 .malloc = zs_zpool_malloc,
445 .free = zs_zpool_free,
Dan Streetmanc7957792014-08-06 16:08:38 -0700446 .map = zs_zpool_map,
447 .unmap = zs_zpool_unmap,
448 .total_size = zs_zpool_total_size,
449};
450
Kees Cook137f8cf2014-08-29 15:18:40 -0700451MODULE_ALIAS("zpool-zsmalloc");
Dan Streetmanc7957792014-08-06 16:08:38 -0700452#endif /* CONFIG_ZPOOL */
453
Nitin Gupta61989a82012-01-09 16:51:56 -0600454/* per-cpu VM mapping areas for zspage accesses that cross page boundaries */
455static DEFINE_PER_CPU(struct mapping_area, zs_map_area);
456
Minchan Kim48b48002016-07-26 15:23:31 -0700457static bool is_zspage_isolated(struct zspage *zspage)
458{
459 return zspage->isolated;
460}
461
Nick Desaulniers3457f412017-07-10 15:47:26 -0700462static __maybe_unused int is_first_page(struct page *page)
Nitin Gupta61989a82012-01-09 16:51:56 -0600463{
Minchan Kima27545bf2012-04-25 15:23:09 +0900464 return PagePrivate(page);
Nitin Gupta61989a82012-01-09 16:51:56 -0600465}
466
Minchan Kim48b48002016-07-26 15:23:31 -0700467/* Protected by class->lock */
Minchan Kim37836892016-07-26 15:23:23 -0700468static inline int get_zspage_inuse(struct zspage *zspage)
Nitin Gupta61989a82012-01-09 16:51:56 -0600469{
Minchan Kim37836892016-07-26 15:23:23 -0700470 return zspage->inuse;
Nitin Gupta61989a82012-01-09 16:51:56 -0600471}
472
Minchan Kim37836892016-07-26 15:23:23 -0700473static inline void set_zspage_inuse(struct zspage *zspage, int val)
Minchan Kim4f420472016-07-26 15:23:17 -0700474{
Minchan Kim37836892016-07-26 15:23:23 -0700475 zspage->inuse = val;
Minchan Kim4f420472016-07-26 15:23:17 -0700476}
477
Minchan Kim37836892016-07-26 15:23:23 -0700478static inline void mod_zspage_inuse(struct zspage *zspage, int val)
Minchan Kim4f420472016-07-26 15:23:17 -0700479{
Minchan Kim37836892016-07-26 15:23:23 -0700480 zspage->inuse += val;
Minchan Kim4f420472016-07-26 15:23:17 -0700481}
482
Minchan Kim48b48002016-07-26 15:23:31 -0700483static inline struct page *get_first_page(struct zspage *zspage)
484{
485 struct page *first_page = zspage->first_page;
486
487 VM_BUG_ON_PAGE(!is_first_page(first_page), first_page);
488 return first_page;
489}
490
Minchan Kim4f420472016-07-26 15:23:17 -0700491static inline int get_first_obj_offset(struct page *page)
492{
Minchan Kim48b48002016-07-26 15:23:31 -0700493 return page->units;
Minchan Kim4f420472016-07-26 15:23:17 -0700494}
495
496static inline void set_first_obj_offset(struct page *page, int offset)
497{
Minchan Kim48b48002016-07-26 15:23:31 -0700498 page->units = offset;
Minchan Kim4f420472016-07-26 15:23:17 -0700499}
500
Minchan Kimbfd093f2016-07-26 15:23:28 -0700501static inline unsigned int get_freeobj(struct zspage *zspage)
Minchan Kim4f420472016-07-26 15:23:17 -0700502{
Minchan Kimbfd093f2016-07-26 15:23:28 -0700503 return zspage->freeobj;
Minchan Kim4f420472016-07-26 15:23:17 -0700504}
505
Minchan Kimbfd093f2016-07-26 15:23:28 -0700506static inline void set_freeobj(struct zspage *zspage, unsigned int obj)
Minchan Kim4f420472016-07-26 15:23:17 -0700507{
Minchan Kimbfd093f2016-07-26 15:23:28 -0700508 zspage->freeobj = obj;
Minchan Kim4f420472016-07-26 15:23:17 -0700509}
510
Minchan Kim37836892016-07-26 15:23:23 -0700511static void get_zspage_mapping(struct zspage *zspage,
Minchan Kima4209462016-05-20 16:59:36 -0700512 unsigned int *class_idx,
Nitin Gupta61989a82012-01-09 16:51:56 -0600513 enum fullness_group *fullness)
514{
Minchan Kim48b48002016-07-26 15:23:31 -0700515 BUG_ON(zspage->magic != ZSPAGE_MAGIC);
516
Minchan Kim37836892016-07-26 15:23:23 -0700517 *fullness = zspage->fullness;
518 *class_idx = zspage->class;
Nitin Gupta61989a82012-01-09 16:51:56 -0600519}
520
Minchan Kim37836892016-07-26 15:23:23 -0700521static void set_zspage_mapping(struct zspage *zspage,
Minchan Kima4209462016-05-20 16:59:36 -0700522 unsigned int class_idx,
Nitin Gupta61989a82012-01-09 16:51:56 -0600523 enum fullness_group fullness)
524{
Minchan Kim37836892016-07-26 15:23:23 -0700525 zspage->class = class_idx;
526 zspage->fullness = fullness;
Nitin Gupta61989a82012-01-09 16:51:56 -0600527}
528
Nitin Cuptac3e3e88a2013-12-11 11:04:37 +0900529/*
530 * zsmalloc divides the pool into various size classes where each
531 * class maintains a list of zspages where each zspage is divided
532 * into equal sized chunks. Each allocation falls into one of these
533 * classes depending on its size. This function returns index of the
534 * size class which has chunk size big enough to hold the give size.
535 */
Nitin Gupta61989a82012-01-09 16:51:56 -0600536static int get_size_class_index(int size)
537{
538 int idx = 0;
539
540 if (likely(size > ZS_MIN_ALLOC_SIZE))
541 idx = DIV_ROUND_UP(size - ZS_MIN_ALLOC_SIZE,
542 ZS_SIZE_CLASS_DELTA);
543
Jerome Marchandcf8e0fed2017-07-10 15:50:18 -0700544 return min_t(int, ZS_SIZE_CLASSES - 1, idx);
Nitin Gupta61989a82012-01-09 16:51:56 -0600545}
546
Matthias Kaehlcke3eb95fe2017-09-08 16:13:02 -0700547/* type can be of enum type zs_stat_type or fullness_group */
Minchan Kim248ca1b2015-04-15 16:15:42 -0700548static inline void zs_stat_inc(struct size_class *class,
Matthias Kaehlcke3eb95fe2017-09-08 16:13:02 -0700549 int type, unsigned long cnt)
Minchan Kim248ca1b2015-04-15 16:15:42 -0700550{
Minchan Kim48b48002016-07-26 15:23:31 -0700551 class->stats.objs[type] += cnt;
Minchan Kim248ca1b2015-04-15 16:15:42 -0700552}
553
Matthias Kaehlcke3eb95fe2017-09-08 16:13:02 -0700554/* type can be of enum type zs_stat_type or fullness_group */
Minchan Kim248ca1b2015-04-15 16:15:42 -0700555static inline void zs_stat_dec(struct size_class *class,
Matthias Kaehlcke3eb95fe2017-09-08 16:13:02 -0700556 int type, unsigned long cnt)
Minchan Kim248ca1b2015-04-15 16:15:42 -0700557{
Minchan Kim48b48002016-07-26 15:23:31 -0700558 class->stats.objs[type] -= cnt;
Minchan Kim248ca1b2015-04-15 16:15:42 -0700559}
560
Matthias Kaehlcke3eb95fe2017-09-08 16:13:02 -0700561/* type can be of enum type zs_stat_type or fullness_group */
Minchan Kim248ca1b2015-04-15 16:15:42 -0700562static inline unsigned long zs_stat_get(struct size_class *class,
Matthias Kaehlcke3eb95fe2017-09-08 16:13:02 -0700563 int type)
Minchan Kim248ca1b2015-04-15 16:15:42 -0700564{
Minchan Kim48b48002016-07-26 15:23:31 -0700565 return class->stats.objs[type];
Minchan Kim248ca1b2015-04-15 16:15:42 -0700566}
567
Sergey Senozhatsky57244592015-09-08 15:04:27 -0700568#ifdef CONFIG_ZSMALLOC_STAT
569
Dan Streetman4abaac92016-05-26 15:16:27 -0700570static void __init zs_stat_init(void)
Minchan Kim248ca1b2015-04-15 16:15:42 -0700571{
Dan Streetman4abaac92016-05-26 15:16:27 -0700572 if (!debugfs_initialized()) {
573 pr_warn("debugfs not available, stat dir not created\n");
574 return;
575 }
Minchan Kim248ca1b2015-04-15 16:15:42 -0700576
577 zs_stat_root = debugfs_create_dir("zsmalloc", NULL);
578 if (!zs_stat_root)
Dan Streetman4abaac92016-05-26 15:16:27 -0700579 pr_warn("debugfs 'zsmalloc' stat dir creation failed\n");
Minchan Kim248ca1b2015-04-15 16:15:42 -0700580}
581
582static void __exit zs_stat_exit(void)
583{
584 debugfs_remove_recursive(zs_stat_root);
585}
586
Sergey Senozhatsky1120ed52016-03-17 14:20:42 -0700587static unsigned long zs_can_compact(struct size_class *class);
588
Minchan Kim248ca1b2015-04-15 16:15:42 -0700589static int zs_stats_size_show(struct seq_file *s, void *v)
590{
591 int i;
592 struct zs_pool *pool = s->private;
593 struct size_class *class;
594 int objs_per_zspage;
595 unsigned long class_almost_full, class_almost_empty;
Sergey Senozhatsky1120ed52016-03-17 14:20:42 -0700596 unsigned long obj_allocated, obj_used, pages_used, freeable;
Minchan Kim248ca1b2015-04-15 16:15:42 -0700597 unsigned long total_class_almost_full = 0, total_class_almost_empty = 0;
598 unsigned long total_objs = 0, total_used_objs = 0, total_pages = 0;
Sergey Senozhatsky1120ed52016-03-17 14:20:42 -0700599 unsigned long total_freeable = 0;
Minchan Kim248ca1b2015-04-15 16:15:42 -0700600
Sergey Senozhatsky1120ed52016-03-17 14:20:42 -0700601 seq_printf(s, " %5s %5s %11s %12s %13s %10s %10s %16s %8s\n",
Minchan Kim248ca1b2015-04-15 16:15:42 -0700602 "class", "size", "almost_full", "almost_empty",
603 "obj_allocated", "obj_used", "pages_used",
Sergey Senozhatsky1120ed52016-03-17 14:20:42 -0700604 "pages_per_zspage", "freeable");
Minchan Kim248ca1b2015-04-15 16:15:42 -0700605
Jerome Marchandcf8e0fed2017-07-10 15:50:18 -0700606 for (i = 0; i < ZS_SIZE_CLASSES; i++) {
Minchan Kim248ca1b2015-04-15 16:15:42 -0700607 class = pool->size_class[i];
608
609 if (class->index != i)
610 continue;
611
612 spin_lock(&class->lock);
613 class_almost_full = zs_stat_get(class, CLASS_ALMOST_FULL);
614 class_almost_empty = zs_stat_get(class, CLASS_ALMOST_EMPTY);
615 obj_allocated = zs_stat_get(class, OBJ_ALLOCATED);
616 obj_used = zs_stat_get(class, OBJ_USED);
Sergey Senozhatsky1120ed52016-03-17 14:20:42 -0700617 freeable = zs_can_compact(class);
Minchan Kim248ca1b2015-04-15 16:15:42 -0700618 spin_unlock(&class->lock);
619
Ganesh Mahendranb4fd07a2016-07-28 15:47:49 -0700620 objs_per_zspage = class->objs_per_zspage;
Minchan Kim248ca1b2015-04-15 16:15:42 -0700621 pages_used = obj_allocated / objs_per_zspage *
622 class->pages_per_zspage;
623
Sergey Senozhatsky1120ed52016-03-17 14:20:42 -0700624 seq_printf(s, " %5u %5u %11lu %12lu %13lu"
625 " %10lu %10lu %16d %8lu\n",
Minchan Kim248ca1b2015-04-15 16:15:42 -0700626 i, class->size, class_almost_full, class_almost_empty,
627 obj_allocated, obj_used, pages_used,
Sergey Senozhatsky1120ed52016-03-17 14:20:42 -0700628 class->pages_per_zspage, freeable);
Minchan Kim248ca1b2015-04-15 16:15:42 -0700629
630 total_class_almost_full += class_almost_full;
631 total_class_almost_empty += class_almost_empty;
632 total_objs += obj_allocated;
633 total_used_objs += obj_used;
634 total_pages += pages_used;
Sergey Senozhatsky1120ed52016-03-17 14:20:42 -0700635 total_freeable += freeable;
Minchan Kim248ca1b2015-04-15 16:15:42 -0700636 }
637
638 seq_puts(s, "\n");
Sergey Senozhatsky1120ed52016-03-17 14:20:42 -0700639 seq_printf(s, " %5s %5s %11lu %12lu %13lu %10lu %10lu %16s %8lu\n",
Minchan Kim248ca1b2015-04-15 16:15:42 -0700640 "Total", "", total_class_almost_full,
641 total_class_almost_empty, total_objs,
Sergey Senozhatsky1120ed52016-03-17 14:20:42 -0700642 total_used_objs, total_pages, "", total_freeable);
Minchan Kim248ca1b2015-04-15 16:15:42 -0700643
644 return 0;
645}
Andy Shevchenko5ad35092018-04-05 16:23:16 -0700646DEFINE_SHOW_ATTRIBUTE(zs_stats_size);
Minchan Kim248ca1b2015-04-15 16:15:42 -0700647
Dan Streetmand34f6152016-05-20 16:59:56 -0700648static void zs_pool_stat_create(struct zs_pool *pool, const char *name)
Minchan Kim248ca1b2015-04-15 16:15:42 -0700649{
650 struct dentry *entry;
651
Dan Streetman4abaac92016-05-26 15:16:27 -0700652 if (!zs_stat_root) {
653 pr_warn("no root stat dir, not creating <%s> stat dir\n", name);
Dan Streetmand34f6152016-05-20 16:59:56 -0700654 return;
Dan Streetman4abaac92016-05-26 15:16:27 -0700655 }
Minchan Kim248ca1b2015-04-15 16:15:42 -0700656
657 entry = debugfs_create_dir(name, zs_stat_root);
658 if (!entry) {
659 pr_warn("debugfs dir <%s> creation failed\n", name);
Dan Streetmand34f6152016-05-20 16:59:56 -0700660 return;
Minchan Kim248ca1b2015-04-15 16:15:42 -0700661 }
662 pool->stat_dentry = entry;
663
664 entry = debugfs_create_file("classes", S_IFREG | S_IRUGO,
Andy Shevchenko5ad35092018-04-05 16:23:16 -0700665 pool->stat_dentry, pool, &zs_stats_size_fops);
Minchan Kim248ca1b2015-04-15 16:15:42 -0700666 if (!entry) {
667 pr_warn("%s: debugfs file entry <%s> creation failed\n",
668 name, "classes");
Dan Streetman4abaac92016-05-26 15:16:27 -0700669 debugfs_remove_recursive(pool->stat_dentry);
670 pool->stat_dentry = NULL;
Minchan Kim248ca1b2015-04-15 16:15:42 -0700671 }
Minchan Kim248ca1b2015-04-15 16:15:42 -0700672}
673
674static void zs_pool_stat_destroy(struct zs_pool *pool)
675{
676 debugfs_remove_recursive(pool->stat_dentry);
677}
678
679#else /* CONFIG_ZSMALLOC_STAT */
Dan Streetman4abaac92016-05-26 15:16:27 -0700680static void __init zs_stat_init(void)
Minchan Kim248ca1b2015-04-15 16:15:42 -0700681{
Minchan Kim248ca1b2015-04-15 16:15:42 -0700682}
683
684static void __exit zs_stat_exit(void)
685{
686}
687
Dan Streetmand34f6152016-05-20 16:59:56 -0700688static inline void zs_pool_stat_create(struct zs_pool *pool, const char *name)
Minchan Kim248ca1b2015-04-15 16:15:42 -0700689{
Minchan Kim248ca1b2015-04-15 16:15:42 -0700690}
691
692static inline void zs_pool_stat_destroy(struct zs_pool *pool)
693{
694}
Minchan Kim248ca1b2015-04-15 16:15:42 -0700695#endif
696
Minchan Kim48b48002016-07-26 15:23:31 -0700697
Nitin Cuptac3e3e88a2013-12-11 11:04:37 +0900698/*
699 * For each size class, zspages are divided into different groups
700 * depending on how "full" they are. This was done so that we could
701 * easily find empty or nearly empty zspages when we try to shrink
702 * the pool (not yet implemented). This function returns fullness
703 * status of the given page.
704 */
Minchan Kim1fc6e272016-07-26 15:23:11 -0700705static enum fullness_group get_fullness_group(struct size_class *class,
Minchan Kim37836892016-07-26 15:23:23 -0700706 struct zspage *zspage)
Nitin Gupta61989a82012-01-09 16:51:56 -0600707{
Minchan Kim1fc6e272016-07-26 15:23:11 -0700708 int inuse, objs_per_zspage;
Nitin Gupta61989a82012-01-09 16:51:56 -0600709 enum fullness_group fg;
Minchan Kim830e4bc2016-05-20 16:59:39 -0700710
Minchan Kim37836892016-07-26 15:23:23 -0700711 inuse = get_zspage_inuse(zspage);
Minchan Kim1fc6e272016-07-26 15:23:11 -0700712 objs_per_zspage = class->objs_per_zspage;
Nitin Gupta61989a82012-01-09 16:51:56 -0600713
714 if (inuse == 0)
715 fg = ZS_EMPTY;
Minchan Kim1fc6e272016-07-26 15:23:11 -0700716 else if (inuse == objs_per_zspage)
Nitin Gupta61989a82012-01-09 16:51:56 -0600717 fg = ZS_FULL;
Minchan Kim1fc6e272016-07-26 15:23:11 -0700718 else if (inuse <= 3 * objs_per_zspage / fullness_threshold_frac)
Nitin Gupta61989a82012-01-09 16:51:56 -0600719 fg = ZS_ALMOST_EMPTY;
720 else
721 fg = ZS_ALMOST_FULL;
722
723 return fg;
724}
725
Nitin Cuptac3e3e88a2013-12-11 11:04:37 +0900726/*
727 * Each size class maintains various freelists and zspages are assigned
728 * to one of these freelists based on the number of live objects they
729 * have. This functions inserts the given zspage into the freelist
730 * identified by <class, fullness_group>.
731 */
Minchan Kim251cbb92016-05-20 16:59:42 -0700732static void insert_zspage(struct size_class *class,
Minchan Kim37836892016-07-26 15:23:23 -0700733 struct zspage *zspage,
734 enum fullness_group fullness)
Nitin Gupta61989a82012-01-09 16:51:56 -0600735{
Minchan Kim37836892016-07-26 15:23:23 -0700736 struct zspage *head;
Nitin Gupta61989a82012-01-09 16:51:56 -0600737
Minchan Kim48b48002016-07-26 15:23:31 -0700738 zs_stat_inc(class, fullness, 1);
Minchan Kim37836892016-07-26 15:23:23 -0700739 head = list_first_entry_or_null(&class->fullness_list[fullness],
740 struct zspage, list);
Sergey Senozhatsky58f17112015-09-08 15:04:44 -0700741 /*
Minchan Kim37836892016-07-26 15:23:23 -0700742 * We want to see more ZS_FULL pages and less almost empty/full.
743 * Put pages with higher ->inuse first.
Sergey Senozhatsky58f17112015-09-08 15:04:44 -0700744 */
Minchan Kim37836892016-07-26 15:23:23 -0700745 if (head) {
746 if (get_zspage_inuse(zspage) < get_zspage_inuse(head)) {
747 list_add(&zspage->list, &head->list);
748 return;
749 }
750 }
751 list_add(&zspage->list, &class->fullness_list[fullness]);
Nitin Gupta61989a82012-01-09 16:51:56 -0600752}
753
Nitin Cuptac3e3e88a2013-12-11 11:04:37 +0900754/*
755 * This function removes the given zspage from the freelist identified
756 * by <class, fullness_group>.
757 */
Minchan Kim251cbb92016-05-20 16:59:42 -0700758static void remove_zspage(struct size_class *class,
Minchan Kim37836892016-07-26 15:23:23 -0700759 struct zspage *zspage,
760 enum fullness_group fullness)
Nitin Gupta61989a82012-01-09 16:51:56 -0600761{
Minchan Kim37836892016-07-26 15:23:23 -0700762 VM_BUG_ON(list_empty(&class->fullness_list[fullness]));
Minchan Kim48b48002016-07-26 15:23:31 -0700763 VM_BUG_ON(is_zspage_isolated(zspage));
Nitin Gupta61989a82012-01-09 16:51:56 -0600764
Minchan Kim37836892016-07-26 15:23:23 -0700765 list_del_init(&zspage->list);
Minchan Kim48b48002016-07-26 15:23:31 -0700766 zs_stat_dec(class, fullness, 1);
Nitin Gupta61989a82012-01-09 16:51:56 -0600767}
768
Nitin Cuptac3e3e88a2013-12-11 11:04:37 +0900769/*
770 * Each size class maintains zspages in different fullness groups depending
771 * on the number of live objects they contain. When allocating or freeing
772 * objects, the fullness status of the page can change, say, from ALMOST_FULL
773 * to ALMOST_EMPTY when freeing an object. This function checks if such
774 * a status change has occurred for the given page and accordingly moves the
775 * page from the freelist of the old fullness group to that of the new
776 * fullness group.
777 */
Minchan Kimc7806262015-04-15 16:15:26 -0700778static enum fullness_group fix_fullness_group(struct size_class *class,
Minchan Kim37836892016-07-26 15:23:23 -0700779 struct zspage *zspage)
Nitin Gupta61989a82012-01-09 16:51:56 -0600780{
781 int class_idx;
Nitin Gupta61989a82012-01-09 16:51:56 -0600782 enum fullness_group currfg, newfg;
783
Minchan Kim37836892016-07-26 15:23:23 -0700784 get_zspage_mapping(zspage, &class_idx, &currfg);
785 newfg = get_fullness_group(class, zspage);
Nitin Gupta61989a82012-01-09 16:51:56 -0600786 if (newfg == currfg)
787 goto out;
788
Minchan Kim48b48002016-07-26 15:23:31 -0700789 if (!is_zspage_isolated(zspage)) {
790 remove_zspage(class, zspage, currfg);
791 insert_zspage(class, zspage, newfg);
792 }
793
Minchan Kim37836892016-07-26 15:23:23 -0700794 set_zspage_mapping(zspage, class_idx, newfg);
Nitin Gupta61989a82012-01-09 16:51:56 -0600795
796out:
797 return newfg;
798}
799
800/*
801 * We have to decide on how many pages to link together
802 * to form a zspage for each size class. This is important
803 * to reduce wastage due to unusable space left at end of
804 * each zspage which is given as:
Yinghao Xie888fa3742015-04-15 16:15:49 -0700805 * wastage = Zp % class_size
806 * usage = Zp - wastage
Nitin Gupta61989a82012-01-09 16:51:56 -0600807 * where Zp = zspage size = k * PAGE_SIZE where k = 1, 2, ...
808 *
809 * For example, for size class of 3/8 * PAGE_SIZE, we should
810 * link together 3 PAGE_SIZE sized pages to form a zspage
811 * since then we can perfectly fit in 8 such objects.
812 */
Minchan Kim2e3b61542012-05-03 15:40:39 +0900813static int get_pages_per_zspage(int class_size)
Nitin Gupta61989a82012-01-09 16:51:56 -0600814{
815 int i, max_usedpc = 0;
816 /* zspage order which gives maximum used size per KB */
817 int max_usedpc_order = 1;
818
Seth Jennings84d4faa2012-03-05 11:33:21 -0600819 for (i = 1; i <= ZS_MAX_PAGES_PER_ZSPAGE; i++) {
Nitin Gupta61989a82012-01-09 16:51:56 -0600820 int zspage_size;
821 int waste, usedpc;
822
823 zspage_size = i * PAGE_SIZE;
824 waste = zspage_size % class_size;
825 usedpc = (zspage_size - waste) * 100 / zspage_size;
826
827 if (usedpc > max_usedpc) {
828 max_usedpc = usedpc;
829 max_usedpc_order = i;
830 }
831 }
832
833 return max_usedpc_order;
834}
835
Minchan Kim37836892016-07-26 15:23:23 -0700836static struct zspage *get_zspage(struct page *page)
Nitin Gupta61989a82012-01-09 16:51:56 -0600837{
Minchan Kim48b48002016-07-26 15:23:31 -0700838 struct zspage *zspage = (struct zspage *)page->private;
839
840 BUG_ON(zspage->magic != ZSPAGE_MAGIC);
841 return zspage;
Nitin Gupta61989a82012-01-09 16:51:56 -0600842}
843
844static struct page *get_next_page(struct page *page)
845{
Minchan Kim48b48002016-07-26 15:23:31 -0700846 if (unlikely(PageHugeObject(page)))
847 return NULL;
848
849 return page->freelist;
Nitin Gupta61989a82012-01-09 16:51:56 -0600850}
851
Minchan Kimbfd093f2016-07-26 15:23:28 -0700852/**
853 * obj_to_location - get (<page>, <obj_idx>) from encoded object value
Mike Rapoporte8b098f2018-04-05 16:24:57 -0700854 * @obj: the encoded object value
Minchan Kimbfd093f2016-07-26 15:23:28 -0700855 * @page: page object resides in zspage
856 * @obj_idx: object index
Olav Haugan67296872013-11-22 09:30:41 -0800857 */
Minchan Kim312fcae2015-04-15 16:15:30 -0700858static void obj_to_location(unsigned long obj, struct page **page,
Minchan Kimbfd093f2016-07-26 15:23:28 -0700859 unsigned int *obj_idx)
Nitin Gupta61989a82012-01-09 16:51:56 -0600860{
Minchan Kim312fcae2015-04-15 16:15:30 -0700861 obj >>= OBJ_TAG_BITS;
862 *page = pfn_to_page(obj >> OBJ_INDEX_BITS);
863 *obj_idx = (obj & OBJ_INDEX_MASK);
Nitin Gupta61989a82012-01-09 16:51:56 -0600864}
865
Minchan Kimbfd093f2016-07-26 15:23:28 -0700866/**
867 * location_to_obj - get obj value encoded from (<page>, <obj_idx>)
868 * @page: page object resides in zspage
869 * @obj_idx: object index
870 */
871static unsigned long location_to_obj(struct page *page, unsigned int obj_idx)
872{
873 unsigned long obj;
874
875 obj = page_to_pfn(page) << OBJ_INDEX_BITS;
876 obj |= obj_idx & OBJ_INDEX_MASK;
877 obj <<= OBJ_TAG_BITS;
878
879 return obj;
880}
881
Minchan Kim2e40e162015-04-15 16:15:23 -0700882static unsigned long handle_to_obj(unsigned long handle)
883{
884 return *(unsigned long *)handle;
885}
886
Minchan Kim48b48002016-07-26 15:23:31 -0700887static unsigned long obj_to_head(struct page *page, void *obj)
Minchan Kim312fcae2015-04-15 16:15:30 -0700888{
Minchan Kim48b48002016-07-26 15:23:31 -0700889 if (unlikely(PageHugeObject(page))) {
Minchan Kim830e4bc2016-05-20 16:59:39 -0700890 VM_BUG_ON_PAGE(!is_first_page(page), page);
Minchan Kim37836892016-07-26 15:23:23 -0700891 return page->index;
Minchan Kim7b60a682015-04-15 16:15:39 -0700892 } else
893 return *(unsigned long *)obj;
Minchan Kim312fcae2015-04-15 16:15:30 -0700894}
895
Minchan Kim48b48002016-07-26 15:23:31 -0700896static inline int testpin_tag(unsigned long handle)
897{
898 return bit_spin_is_locked(HANDLE_PIN_BIT, (unsigned long *)handle);
899}
900
Minchan Kim312fcae2015-04-15 16:15:30 -0700901static inline int trypin_tag(unsigned long handle)
902{
Minchan Kim1b8320b2016-07-26 15:23:14 -0700903 return bit_spin_trylock(HANDLE_PIN_BIT, (unsigned long *)handle);
Minchan Kim312fcae2015-04-15 16:15:30 -0700904}
905
906static void pin_tag(unsigned long handle)
907{
Minchan Kim1b8320b2016-07-26 15:23:14 -0700908 bit_spin_lock(HANDLE_PIN_BIT, (unsigned long *)handle);
Minchan Kim312fcae2015-04-15 16:15:30 -0700909}
910
911static void unpin_tag(unsigned long handle)
912{
Minchan Kim1b8320b2016-07-26 15:23:14 -0700913 bit_spin_unlock(HANDLE_PIN_BIT, (unsigned long *)handle);
Minchan Kim312fcae2015-04-15 16:15:30 -0700914}
915
Nitin Guptaf4477e92012-04-02 09:13:56 -0500916static void reset_page(struct page *page)
917{
Minchan Kim48b48002016-07-26 15:23:31 -0700918 __ClearPageMovable(page);
Ganesh Mahendran18fd06b2016-07-28 15:48:00 -0700919 ClearPagePrivate(page);
Nitin Guptaf4477e92012-04-02 09:13:56 -0500920 set_page_private(page, 0);
Minchan Kim48b48002016-07-26 15:23:31 -0700921 page_mapcount_reset(page);
922 ClearPageHugeObject(page);
923 page->freelist = NULL;
Nitin Guptaf4477e92012-04-02 09:13:56 -0500924}
925
Minchan Kim48b48002016-07-26 15:23:31 -0700926/*
927 * To prevent zspage destroy during migration, zspage freeing should
928 * hold locks of all pages in the zspage.
929 */
930void lock_zspage(struct zspage *zspage)
931{
932 struct page *page = get_first_page(zspage);
933
934 do {
935 lock_page(page);
936 } while ((page = get_next_page(page)) != NULL);
937}
938
939int trylock_zspage(struct zspage *zspage)
940{
941 struct page *cursor, *fail;
942
943 for (cursor = get_first_page(zspage); cursor != NULL; cursor =
944 get_next_page(cursor)) {
945 if (!trylock_page(cursor)) {
946 fail = cursor;
947 goto unlock;
948 }
949 }
950
951 return 1;
952unlock:
953 for (cursor = get_first_page(zspage); cursor != fail; cursor =
954 get_next_page(cursor))
955 unlock_page(cursor);
956
957 return 0;
958}
959
960static void __free_zspage(struct zs_pool *pool, struct size_class *class,
961 struct zspage *zspage)
Nitin Gupta61989a82012-01-09 16:51:56 -0600962{
Minchan Kim37836892016-07-26 15:23:23 -0700963 struct page *page, *next;
Minchan Kim48b48002016-07-26 15:23:31 -0700964 enum fullness_group fg;
965 unsigned int class_idx;
966
967 get_zspage_mapping(zspage, &class_idx, &fg);
968
969 assert_spin_locked(&class->lock);
Nitin Gupta61989a82012-01-09 16:51:56 -0600970
Minchan Kim37836892016-07-26 15:23:23 -0700971 VM_BUG_ON(get_zspage_inuse(zspage));
Minchan Kim48b48002016-07-26 15:23:31 -0700972 VM_BUG_ON(fg != ZS_EMPTY);
Nitin Gupta61989a82012-01-09 16:51:56 -0600973
Minchan Kim48b48002016-07-26 15:23:31 -0700974 next = page = get_first_page(zspage);
Minchan Kim37836892016-07-26 15:23:23 -0700975 do {
Minchan Kim48b48002016-07-26 15:23:31 -0700976 VM_BUG_ON_PAGE(!PageLocked(page), page);
977 next = get_next_page(page);
Minchan Kim37836892016-07-26 15:23:23 -0700978 reset_page(page);
Minchan Kim48b48002016-07-26 15:23:31 -0700979 unlock_page(page);
Minchan Kim91537fe2016-07-26 15:24:45 -0700980 dec_zone_page_state(page, NR_ZSPAGES);
Minchan Kim37836892016-07-26 15:23:23 -0700981 put_page(page);
982 page = next;
983 } while (page != NULL);
Nitin Gupta61989a82012-01-09 16:51:56 -0600984
Minchan Kim37836892016-07-26 15:23:23 -0700985 cache_free_zspage(pool, zspage);
Minchan Kim48b48002016-07-26 15:23:31 -0700986
Ganesh Mahendranb4fd07a2016-07-28 15:47:49 -0700987 zs_stat_dec(class, OBJ_ALLOCATED, class->objs_per_zspage);
Minchan Kim48b48002016-07-26 15:23:31 -0700988 atomic_long_sub(class->pages_per_zspage,
989 &pool->pages_allocated);
990}
991
992static void free_zspage(struct zs_pool *pool, struct size_class *class,
993 struct zspage *zspage)
994{
995 VM_BUG_ON(get_zspage_inuse(zspage));
996 VM_BUG_ON(list_empty(&zspage->list));
997
998 if (!trylock_zspage(zspage)) {
999 kick_deferred_free(pool);
1000 return;
1001 }
1002
1003 remove_zspage(class, zspage, ZS_EMPTY);
1004 __free_zspage(pool, class, zspage);
Nitin Gupta61989a82012-01-09 16:51:56 -06001005}
1006
1007/* Initialize a newly allocated zspage */
Minchan Kim37836892016-07-26 15:23:23 -07001008static void init_zspage(struct size_class *class, struct zspage *zspage)
Nitin Gupta61989a82012-01-09 16:51:56 -06001009{
Minchan Kimbfd093f2016-07-26 15:23:28 -07001010 unsigned int freeobj = 1;
Nitin Gupta61989a82012-01-09 16:51:56 -06001011 unsigned long off = 0;
Minchan Kim48b48002016-07-26 15:23:31 -07001012 struct page *page = get_first_page(zspage);
Minchan Kim830e4bc2016-05-20 16:59:39 -07001013
Nitin Gupta61989a82012-01-09 16:51:56 -06001014 while (page) {
1015 struct page *next_page;
1016 struct link_free *link;
Minchan Kimaf4ee5e2014-12-12 16:56:58 -08001017 void *vaddr;
Nitin Gupta61989a82012-01-09 16:51:56 -06001018
Minchan Kim37836892016-07-26 15:23:23 -07001019 set_first_obj_offset(page, off);
Nitin Gupta61989a82012-01-09 16:51:56 -06001020
Minchan Kimaf4ee5e2014-12-12 16:56:58 -08001021 vaddr = kmap_atomic(page);
1022 link = (struct link_free *)vaddr + off / sizeof(*link);
Nitin Gupta61989a82012-01-09 16:51:56 -06001023
Dan Streetman5538c562014-10-09 15:30:01 -07001024 while ((off += class->size) < PAGE_SIZE) {
Minchan Kim3b1d9ca2016-07-26 15:23:37 -07001025 link->next = freeobj++ << OBJ_TAG_BITS;
Dan Streetman5538c562014-10-09 15:30:01 -07001026 link += class->size / sizeof(*link);
Nitin Gupta61989a82012-01-09 16:51:56 -06001027 }
1028
1029 /*
1030 * We now come to the last (full or partial) object on this
1031 * page, which must point to the first object on the next
1032 * page (if present)
1033 */
1034 next_page = get_next_page(page);
Minchan Kimbfd093f2016-07-26 15:23:28 -07001035 if (next_page) {
Minchan Kim3b1d9ca2016-07-26 15:23:37 -07001036 link->next = freeobj++ << OBJ_TAG_BITS;
Minchan Kimbfd093f2016-07-26 15:23:28 -07001037 } else {
1038 /*
Minchan Kim3b1d9ca2016-07-26 15:23:37 -07001039 * Reset OBJ_TAG_BITS bit to last link to tell
Minchan Kimbfd093f2016-07-26 15:23:28 -07001040 * whether it's allocated object or not.
1041 */
Nick Desaulniers01a6ad92018-01-31 16:20:15 -08001042 link->next = -1UL << OBJ_TAG_BITS;
Minchan Kimbfd093f2016-07-26 15:23:28 -07001043 }
Minchan Kimaf4ee5e2014-12-12 16:56:58 -08001044 kunmap_atomic(vaddr);
Nitin Gupta61989a82012-01-09 16:51:56 -06001045 page = next_page;
Dan Streetman5538c562014-10-09 15:30:01 -07001046 off %= PAGE_SIZE;
Nitin Gupta61989a82012-01-09 16:51:56 -06001047 }
Minchan Kimbdb0af72016-07-26 15:23:20 -07001048
Minchan Kimbfd093f2016-07-26 15:23:28 -07001049 set_freeobj(zspage, 0);
Nitin Gupta61989a82012-01-09 16:51:56 -06001050}
1051
Minchan Kim48b48002016-07-26 15:23:31 -07001052static void create_page_chain(struct size_class *class, struct zspage *zspage,
1053 struct page *pages[])
Nitin Gupta61989a82012-01-09 16:51:56 -06001054{
Minchan Kimbdb0af72016-07-26 15:23:20 -07001055 int i;
1056 struct page *page;
1057 struct page *prev_page = NULL;
Minchan Kim48b48002016-07-26 15:23:31 -07001058 int nr_pages = class->pages_per_zspage;
Nitin Gupta61989a82012-01-09 16:51:56 -06001059
1060 /*
1061 * Allocate individual pages and link them together as:
Minchan Kim48b48002016-07-26 15:23:31 -07001062 * 1. all pages are linked together using page->freelist
Minchan Kim37836892016-07-26 15:23:23 -07001063 * 2. each sub-page point to zspage using page->private
Nitin Gupta61989a82012-01-09 16:51:56 -06001064 *
Minchan Kim37836892016-07-26 15:23:23 -07001065 * we set PG_private to identify the first page (i.e. no other sub-page
Yisheng Xie22c5cef2017-02-24 14:59:42 -08001066 * has this flag set).
Nitin Gupta61989a82012-01-09 16:51:56 -06001067 */
Minchan Kimbdb0af72016-07-26 15:23:20 -07001068 for (i = 0; i < nr_pages; i++) {
1069 page = pages[i];
Minchan Kim37836892016-07-26 15:23:23 -07001070 set_page_private(page, (unsigned long)zspage);
Minchan Kim48b48002016-07-26 15:23:31 -07001071 page->freelist = NULL;
Minchan Kimbdb0af72016-07-26 15:23:20 -07001072 if (i == 0) {
Minchan Kim37836892016-07-26 15:23:23 -07001073 zspage->first_page = page;
Minchan Kima27545bf2012-04-25 15:23:09 +09001074 SetPagePrivate(page);
Minchan Kim48b48002016-07-26 15:23:31 -07001075 if (unlikely(class->objs_per_zspage == 1 &&
1076 class->pages_per_zspage == 1))
1077 SetPageHugeObject(page);
Minchan Kim37836892016-07-26 15:23:23 -07001078 } else {
Minchan Kim48b48002016-07-26 15:23:31 -07001079 prev_page->freelist = page;
Nitin Gupta61989a82012-01-09 16:51:56 -06001080 }
Nitin Gupta61989a82012-01-09 16:51:56 -06001081 prev_page = page;
1082 }
Minchan Kimbdb0af72016-07-26 15:23:20 -07001083}
Nitin Gupta61989a82012-01-09 16:51:56 -06001084
Minchan Kimbdb0af72016-07-26 15:23:20 -07001085/*
1086 * Allocate a zspage for the given size class
1087 */
Minchan Kim37836892016-07-26 15:23:23 -07001088static struct zspage *alloc_zspage(struct zs_pool *pool,
1089 struct size_class *class,
1090 gfp_t gfp)
Minchan Kimbdb0af72016-07-26 15:23:20 -07001091{
1092 int i;
Minchan Kimbdb0af72016-07-26 15:23:20 -07001093 struct page *pages[ZS_MAX_PAGES_PER_ZSPAGE];
Minchan Kim37836892016-07-26 15:23:23 -07001094 struct zspage *zspage = cache_alloc_zspage(pool, gfp);
1095
1096 if (!zspage)
1097 return NULL;
1098
1099 memset(zspage, 0, sizeof(struct zspage));
Minchan Kim48b48002016-07-26 15:23:31 -07001100 zspage->magic = ZSPAGE_MAGIC;
1101 migrate_lock_init(zspage);
Nitin Gupta61989a82012-01-09 16:51:56 -06001102
Minchan Kimbdb0af72016-07-26 15:23:20 -07001103 for (i = 0; i < class->pages_per_zspage; i++) {
1104 struct page *page;
Nitin Gupta61989a82012-01-09 16:51:56 -06001105
Minchan Kim37836892016-07-26 15:23:23 -07001106 page = alloc_page(gfp);
Minchan Kimbdb0af72016-07-26 15:23:20 -07001107 if (!page) {
Minchan Kim91537fe2016-07-26 15:24:45 -07001108 while (--i >= 0) {
1109 dec_zone_page_state(pages[i], NR_ZSPAGES);
Minchan Kimbdb0af72016-07-26 15:23:20 -07001110 __free_page(pages[i]);
Minchan Kim91537fe2016-07-26 15:24:45 -07001111 }
Minchan Kim37836892016-07-26 15:23:23 -07001112 cache_free_zspage(pool, zspage);
Minchan Kimbdb0af72016-07-26 15:23:20 -07001113 return NULL;
1114 }
Minchan Kim91537fe2016-07-26 15:24:45 -07001115
1116 inc_zone_page_state(page, NR_ZSPAGES);
Minchan Kimbdb0af72016-07-26 15:23:20 -07001117 pages[i] = page;
Nitin Gupta61989a82012-01-09 16:51:56 -06001118 }
1119
Minchan Kim48b48002016-07-26 15:23:31 -07001120 create_page_chain(class, zspage, pages);
Minchan Kim37836892016-07-26 15:23:23 -07001121 init_zspage(class, zspage);
Minchan Kimbdb0af72016-07-26 15:23:20 -07001122
Minchan Kim37836892016-07-26 15:23:23 -07001123 return zspage;
Nitin Gupta61989a82012-01-09 16:51:56 -06001124}
1125
Minchan Kim37836892016-07-26 15:23:23 -07001126static struct zspage *find_get_zspage(struct size_class *class)
Nitin Gupta61989a82012-01-09 16:51:56 -06001127{
1128 int i;
Minchan Kim37836892016-07-26 15:23:23 -07001129 struct zspage *zspage;
Nitin Gupta61989a82012-01-09 16:51:56 -06001130
Minchan Kim48b48002016-07-26 15:23:31 -07001131 for (i = ZS_ALMOST_FULL; i >= ZS_EMPTY; i--) {
Minchan Kim37836892016-07-26 15:23:23 -07001132 zspage = list_first_entry_or_null(&class->fullness_list[i],
1133 struct zspage, list);
1134 if (zspage)
Nitin Gupta61989a82012-01-09 16:51:56 -06001135 break;
1136 }
1137
Minchan Kim37836892016-07-26 15:23:23 -07001138 return zspage;
Nitin Gupta61989a82012-01-09 16:51:56 -06001139}
1140
Minchan Kim1b945ae2013-12-11 11:04:36 +09001141#ifdef CONFIG_PGTABLE_MAPPING
Seth Jenningsf5536462012-07-18 11:55:56 -05001142static inline int __zs_cpu_up(struct mapping_area *area)
Seth Jennings5f6019022012-07-02 16:15:49 -05001143{
Seth Jenningsf5536462012-07-18 11:55:56 -05001144 /*
1145 * Make sure we don't leak memory if a cpu UP notification
1146 * and zs_init() race and both call zs_cpu_up() on the same cpu
1147 */
1148 if (area->vm)
1149 return 0;
1150 area->vm = alloc_vm_area(PAGE_SIZE * 2, NULL);
1151 if (!area->vm)
1152 return -ENOMEM;
1153 return 0;
1154}
1155
1156static inline void __zs_cpu_down(struct mapping_area *area)
1157{
1158 if (area->vm)
1159 free_vm_area(area->vm);
1160 area->vm = NULL;
1161}
1162
1163static inline void *__zs_map_object(struct mapping_area *area,
1164 struct page *pages[2], int off, int size)
1165{
WANG Chaof6f8ed42014-08-06 16:06:58 -07001166 BUG_ON(map_vm_area(area->vm, PAGE_KERNEL, pages));
Seth Jenningsf5536462012-07-18 11:55:56 -05001167 area->vm_addr = area->vm->addr;
1168 return area->vm_addr + off;
1169}
1170
1171static inline void __zs_unmap_object(struct mapping_area *area,
1172 struct page *pages[2], int off, int size)
1173{
1174 unsigned long addr = (unsigned long)area->vm_addr;
Seth Jenningsf5536462012-07-18 11:55:56 -05001175
Joerg Roedeld95abbb2013-03-27 01:43:14 +01001176 unmap_kernel_range(addr, PAGE_SIZE * 2);
Seth Jenningsf5536462012-07-18 11:55:56 -05001177}
1178
Minchan Kim1b945ae2013-12-11 11:04:36 +09001179#else /* CONFIG_PGTABLE_MAPPING */
Seth Jenningsf5536462012-07-18 11:55:56 -05001180
1181static inline int __zs_cpu_up(struct mapping_area *area)
1182{
1183 /*
1184 * Make sure we don't leak memory if a cpu UP notification
1185 * and zs_init() race and both call zs_cpu_up() on the same cpu
1186 */
1187 if (area->vm_buf)
1188 return 0;
Mahendran Ganesh40f9fb82014-12-12 16:57:01 -08001189 area->vm_buf = kmalloc(ZS_MAX_ALLOC_SIZE, GFP_KERNEL);
Seth Jenningsf5536462012-07-18 11:55:56 -05001190 if (!area->vm_buf)
1191 return -ENOMEM;
1192 return 0;
1193}
1194
1195static inline void __zs_cpu_down(struct mapping_area *area)
1196{
Mahendran Ganesh40f9fb82014-12-12 16:57:01 -08001197 kfree(area->vm_buf);
Seth Jenningsf5536462012-07-18 11:55:56 -05001198 area->vm_buf = NULL;
1199}
1200
1201static void *__zs_map_object(struct mapping_area *area,
1202 struct page *pages[2], int off, int size)
1203{
Seth Jennings5f6019022012-07-02 16:15:49 -05001204 int sizes[2];
1205 void *addr;
Seth Jenningsf5536462012-07-18 11:55:56 -05001206 char *buf = area->vm_buf;
Seth Jennings5f6019022012-07-02 16:15:49 -05001207
Seth Jenningsf5536462012-07-18 11:55:56 -05001208 /* disable page faults to match kmap_atomic() return conditions */
1209 pagefault_disable();
1210
1211 /* no read fastpath */
1212 if (area->vm_mm == ZS_MM_WO)
1213 goto out;
Seth Jennings5f6019022012-07-02 16:15:49 -05001214
1215 sizes[0] = PAGE_SIZE - off;
1216 sizes[1] = size - sizes[0];
1217
Seth Jennings5f6019022012-07-02 16:15:49 -05001218 /* copy object to per-cpu buffer */
1219 addr = kmap_atomic(pages[0]);
1220 memcpy(buf, addr + off, sizes[0]);
1221 kunmap_atomic(addr);
1222 addr = kmap_atomic(pages[1]);
1223 memcpy(buf + sizes[0], addr, sizes[1]);
1224 kunmap_atomic(addr);
Seth Jenningsf5536462012-07-18 11:55:56 -05001225out:
1226 return area->vm_buf;
Seth Jennings5f6019022012-07-02 16:15:49 -05001227}
1228
Seth Jenningsf5536462012-07-18 11:55:56 -05001229static void __zs_unmap_object(struct mapping_area *area,
1230 struct page *pages[2], int off, int size)
Seth Jennings5f6019022012-07-02 16:15:49 -05001231{
Seth Jennings5f6019022012-07-02 16:15:49 -05001232 int sizes[2];
1233 void *addr;
Minchan Kim2e40e162015-04-15 16:15:23 -07001234 char *buf;
Seth Jennings5f6019022012-07-02 16:15:49 -05001235
Seth Jenningsf5536462012-07-18 11:55:56 -05001236 /* no write fastpath */
1237 if (area->vm_mm == ZS_MM_RO)
1238 goto out;
Seth Jennings5f6019022012-07-02 16:15:49 -05001239
Minchan Kim7b60a682015-04-15 16:15:39 -07001240 buf = area->vm_buf;
YiPing Xua82cbf02016-03-17 14:20:39 -07001241 buf = buf + ZS_HANDLE_SIZE;
1242 size -= ZS_HANDLE_SIZE;
1243 off += ZS_HANDLE_SIZE;
Minchan Kim2e40e162015-04-15 16:15:23 -07001244
Seth Jennings5f6019022012-07-02 16:15:49 -05001245 sizes[0] = PAGE_SIZE - off;
1246 sizes[1] = size - sizes[0];
1247
1248 /* copy per-cpu buffer to object */
1249 addr = kmap_atomic(pages[0]);
1250 memcpy(addr + off, buf, sizes[0]);
1251 kunmap_atomic(addr);
1252 addr = kmap_atomic(pages[1]);
1253 memcpy(addr, buf + sizes[0], sizes[1]);
1254 kunmap_atomic(addr);
Seth Jenningsf5536462012-07-18 11:55:56 -05001255
1256out:
1257 /* enable page faults to match kunmap_atomic() return conditions */
1258 pagefault_enable();
Seth Jennings5f6019022012-07-02 16:15:49 -05001259}
Nitin Gupta61989a82012-01-09 16:51:56 -06001260
Minchan Kim1b945ae2013-12-11 11:04:36 +09001261#endif /* CONFIG_PGTABLE_MAPPING */
Seth Jenningsf5536462012-07-18 11:55:56 -05001262
Sebastian Andrzej Siewior215c89d2016-11-27 00:13:38 +01001263static int zs_cpu_prepare(unsigned int cpu)
Nitin Gupta61989a82012-01-09 16:51:56 -06001264{
Nitin Gupta61989a82012-01-09 16:51:56 -06001265 struct mapping_area *area;
1266
Sebastian Andrzej Siewior215c89d2016-11-27 00:13:38 +01001267 area = &per_cpu(zs_map_area, cpu);
1268 return __zs_cpu_up(area);
Nitin Gupta61989a82012-01-09 16:51:56 -06001269}
1270
Sebastian Andrzej Siewior215c89d2016-11-27 00:13:38 +01001271static int zs_cpu_dead(unsigned int cpu)
Nitin Gupta61989a82012-01-09 16:51:56 -06001272{
Sebastian Andrzej Siewior215c89d2016-11-27 00:13:38 +01001273 struct mapping_area *area;
Nitin Gupta61989a82012-01-09 16:51:56 -06001274
Sebastian Andrzej Siewior215c89d2016-11-27 00:13:38 +01001275 area = &per_cpu(zs_map_area, cpu);
1276 __zs_cpu_down(area);
1277 return 0;
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001278}
1279
Ganesh Mahendran64d90462016-07-28 15:47:51 -07001280static bool can_merge(struct size_class *prev, int pages_per_zspage,
1281 int objs_per_zspage)
Joonsoo Kim9eec4cd2014-12-12 16:56:44 -08001282{
Ganesh Mahendran64d90462016-07-28 15:47:51 -07001283 if (prev->pages_per_zspage == pages_per_zspage &&
1284 prev->objs_per_zspage == objs_per_zspage)
1285 return true;
Joonsoo Kim9eec4cd2014-12-12 16:56:44 -08001286
Ganesh Mahendran64d90462016-07-28 15:47:51 -07001287 return false;
Joonsoo Kim9eec4cd2014-12-12 16:56:44 -08001288}
1289
Minchan Kim37836892016-07-26 15:23:23 -07001290static bool zspage_full(struct size_class *class, struct zspage *zspage)
Minchan Kim312fcae2015-04-15 16:15:30 -07001291{
Minchan Kim37836892016-07-26 15:23:23 -07001292 return get_zspage_inuse(zspage) == class->objs_per_zspage;
Minchan Kim312fcae2015-04-15 16:15:30 -07001293}
1294
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001295unsigned long zs_get_total_pages(struct zs_pool *pool)
1296{
1297 return atomic_long_read(&pool->pages_allocated);
1298}
1299EXPORT_SYMBOL_GPL(zs_get_total_pages);
1300
1301/**
1302 * zs_map_object - get address of allocated object from handle.
1303 * @pool: pool from which the object was allocated
1304 * @handle: handle returned from zs_malloc
Mike Rapoporte8b098f2018-04-05 16:24:57 -07001305 * @mm: maping mode to use
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001306 *
1307 * Before using an object allocated from zs_malloc, it must be mapped using
1308 * this function. When done with the object, it must be unmapped using
1309 * zs_unmap_object.
1310 *
1311 * Only one object can be mapped per cpu at a time. There is no protection
1312 * against nested mappings.
1313 *
1314 * This function returns with preemption and page faults disabled.
1315 */
1316void *zs_map_object(struct zs_pool *pool, unsigned long handle,
1317 enum zs_mapmode mm)
1318{
Minchan Kim37836892016-07-26 15:23:23 -07001319 struct zspage *zspage;
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001320 struct page *page;
Minchan Kimbfd093f2016-07-26 15:23:28 -07001321 unsigned long obj, off;
1322 unsigned int obj_idx;
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001323
1324 unsigned int class_idx;
1325 enum fullness_group fg;
1326 struct size_class *class;
1327 struct mapping_area *area;
1328 struct page *pages[2];
Minchan Kim2e40e162015-04-15 16:15:23 -07001329 void *ret;
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001330
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001331 /*
1332 * Because we use per-cpu mapping areas shared among the
1333 * pools/users, we can't allow mapping in interrupt context
1334 * because it can corrupt another users mappings.
1335 */
Sergey Senozhatsky1aedcaf2017-11-15 17:34:03 -08001336 BUG_ON(in_interrupt());
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001337
Minchan Kim312fcae2015-04-15 16:15:30 -07001338 /* From now on, migration cannot move the object */
1339 pin_tag(handle);
1340
Minchan Kim2e40e162015-04-15 16:15:23 -07001341 obj = handle_to_obj(handle);
1342 obj_to_location(obj, &page, &obj_idx);
Minchan Kim37836892016-07-26 15:23:23 -07001343 zspage = get_zspage(page);
Minchan Kim48b48002016-07-26 15:23:31 -07001344
1345 /* migration cannot move any subpage in this zspage */
1346 migrate_read_lock(zspage);
1347
Minchan Kim37836892016-07-26 15:23:23 -07001348 get_zspage_mapping(zspage, &class_idx, &fg);
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001349 class = pool->size_class[class_idx];
Minchan Kimbfd093f2016-07-26 15:23:28 -07001350 off = (class->size * obj_idx) & ~PAGE_MASK;
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001351
1352 area = &get_cpu_var(zs_map_area);
1353 area->vm_mm = mm;
1354 if (off + class->size <= PAGE_SIZE) {
1355 /* this object is contained entirely within a page */
1356 area->vm_addr = kmap_atomic(page);
Minchan Kim2e40e162015-04-15 16:15:23 -07001357 ret = area->vm_addr + off;
1358 goto out;
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001359 }
1360
1361 /* this object spans two pages */
1362 pages[0] = page;
1363 pages[1] = get_next_page(page);
1364 BUG_ON(!pages[1]);
1365
Minchan Kim2e40e162015-04-15 16:15:23 -07001366 ret = __zs_map_object(area, pages, off, class->size);
1367out:
Minchan Kim48b48002016-07-26 15:23:31 -07001368 if (likely(!PageHugeObject(page)))
Minchan Kim7b60a682015-04-15 16:15:39 -07001369 ret += ZS_HANDLE_SIZE;
1370
1371 return ret;
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001372}
1373EXPORT_SYMBOL_GPL(zs_map_object);
1374
1375void zs_unmap_object(struct zs_pool *pool, unsigned long handle)
1376{
Minchan Kim37836892016-07-26 15:23:23 -07001377 struct zspage *zspage;
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001378 struct page *page;
Minchan Kimbfd093f2016-07-26 15:23:28 -07001379 unsigned long obj, off;
1380 unsigned int obj_idx;
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001381
1382 unsigned int class_idx;
1383 enum fullness_group fg;
1384 struct size_class *class;
1385 struct mapping_area *area;
1386
Minchan Kim2e40e162015-04-15 16:15:23 -07001387 obj = handle_to_obj(handle);
1388 obj_to_location(obj, &page, &obj_idx);
Minchan Kim37836892016-07-26 15:23:23 -07001389 zspage = get_zspage(page);
1390 get_zspage_mapping(zspage, &class_idx, &fg);
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001391 class = pool->size_class[class_idx];
Minchan Kimbfd093f2016-07-26 15:23:28 -07001392 off = (class->size * obj_idx) & ~PAGE_MASK;
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001393
1394 area = this_cpu_ptr(&zs_map_area);
1395 if (off + class->size <= PAGE_SIZE)
1396 kunmap_atomic(area->vm_addr);
1397 else {
1398 struct page *pages[2];
1399
1400 pages[0] = page;
1401 pages[1] = get_next_page(page);
1402 BUG_ON(!pages[1]);
1403
1404 __zs_unmap_object(area, pages, off, class->size);
1405 }
1406 put_cpu_var(zs_map_area);
Minchan Kim48b48002016-07-26 15:23:31 -07001407
1408 migrate_read_unlock(zspage);
Minchan Kim312fcae2015-04-15 16:15:30 -07001409 unpin_tag(handle);
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001410}
1411EXPORT_SYMBOL_GPL(zs_unmap_object);
1412
Sergey Senozhatsky010b4952018-04-05 16:24:43 -07001413/**
1414 * zs_huge_class_size() - Returns the size (in bytes) of the first huge
1415 * zsmalloc &size_class.
1416 * @pool: zsmalloc pool to use
1417 *
1418 * The function returns the size of the first huge class - any object of equal
1419 * or bigger size will be stored in zspage consisting of a single physical
1420 * page.
1421 *
1422 * Context: Any context.
1423 *
1424 * Return: the size (in bytes) of the first huge zsmalloc &size_class.
1425 */
1426size_t zs_huge_class_size(struct zs_pool *pool)
1427{
1428 return huge_class_size;
1429}
1430EXPORT_SYMBOL_GPL(zs_huge_class_size);
1431
Minchan Kim251cbb92016-05-20 16:59:42 -07001432static unsigned long obj_malloc(struct size_class *class,
Minchan Kim37836892016-07-26 15:23:23 -07001433 struct zspage *zspage, unsigned long handle)
Minchan Kimc7806262015-04-15 16:15:26 -07001434{
Minchan Kimbfd093f2016-07-26 15:23:28 -07001435 int i, nr_page, offset;
Minchan Kimc7806262015-04-15 16:15:26 -07001436 unsigned long obj;
1437 struct link_free *link;
1438
1439 struct page *m_page;
Minchan Kimbfd093f2016-07-26 15:23:28 -07001440 unsigned long m_offset;
Minchan Kimc7806262015-04-15 16:15:26 -07001441 void *vaddr;
1442
Minchan Kim312fcae2015-04-15 16:15:30 -07001443 handle |= OBJ_ALLOCATED_TAG;
Minchan Kim37836892016-07-26 15:23:23 -07001444 obj = get_freeobj(zspage);
Minchan Kimbfd093f2016-07-26 15:23:28 -07001445
1446 offset = obj * class->size;
1447 nr_page = offset >> PAGE_SHIFT;
1448 m_offset = offset & ~PAGE_MASK;
1449 m_page = get_first_page(zspage);
1450
1451 for (i = 0; i < nr_page; i++)
1452 m_page = get_next_page(m_page);
Minchan Kimc7806262015-04-15 16:15:26 -07001453
1454 vaddr = kmap_atomic(m_page);
1455 link = (struct link_free *)vaddr + m_offset / sizeof(*link);
Minchan Kim3b1d9ca2016-07-26 15:23:37 -07001456 set_freeobj(zspage, link->next >> OBJ_TAG_BITS);
Minchan Kim48b48002016-07-26 15:23:31 -07001457 if (likely(!PageHugeObject(m_page)))
Minchan Kim7b60a682015-04-15 16:15:39 -07001458 /* record handle in the header of allocated chunk */
1459 link->handle = handle;
1460 else
Minchan Kim37836892016-07-26 15:23:23 -07001461 /* record handle to page->index */
1462 zspage->first_page->index = handle;
1463
Minchan Kimc7806262015-04-15 16:15:26 -07001464 kunmap_atomic(vaddr);
Minchan Kim37836892016-07-26 15:23:23 -07001465 mod_zspage_inuse(zspage, 1);
Minchan Kimc7806262015-04-15 16:15:26 -07001466 zs_stat_inc(class, OBJ_USED, 1);
1467
Minchan Kimbfd093f2016-07-26 15:23:28 -07001468 obj = location_to_obj(m_page, obj);
1469
Minchan Kimc7806262015-04-15 16:15:26 -07001470 return obj;
1471}
1472
1473
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001474/**
1475 * zs_malloc - Allocate block of given size from pool.
1476 * @pool: pool to allocate from
1477 * @size: size of block to allocate
Ganesh Mahendranfd854462016-07-28 15:47:54 -07001478 * @gfp: gfp flags when allocating object
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001479 *
1480 * On success, handle to the allocated object is returned,
1481 * otherwise 0.
1482 * Allocation requests with size > ZS_MAX_ALLOC_SIZE will fail.
1483 */
Sergey Senozhatskyd0d8da22016-05-20 16:59:48 -07001484unsigned long zs_malloc(struct zs_pool *pool, size_t size, gfp_t gfp)
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001485{
Minchan Kim2e40e162015-04-15 16:15:23 -07001486 unsigned long handle, obj;
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001487 struct size_class *class;
Minchan Kim48b48002016-07-26 15:23:31 -07001488 enum fullness_group newfg;
Minchan Kim37836892016-07-26 15:23:23 -07001489 struct zspage *zspage;
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001490
Minchan Kim7b60a682015-04-15 16:15:39 -07001491 if (unlikely(!size || size > ZS_MAX_ALLOC_SIZE))
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001492 return 0;
1493
Minchan Kim37836892016-07-26 15:23:23 -07001494 handle = cache_alloc_handle(pool, gfp);
Minchan Kim2e40e162015-04-15 16:15:23 -07001495 if (!handle)
1496 return 0;
1497
1498 /* extra space in chunk to keep the handle */
1499 size += ZS_HANDLE_SIZE;
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001500 class = pool->size_class[get_size_class_index(size)];
1501
1502 spin_lock(&class->lock);
Minchan Kim37836892016-07-26 15:23:23 -07001503 zspage = find_get_zspage(class);
Minchan Kim48b48002016-07-26 15:23:31 -07001504 if (likely(zspage)) {
1505 obj = obj_malloc(class, zspage, handle);
1506 /* Now move the zspage to another fullness group, if required */
1507 fix_fullness_group(class, zspage);
1508 record_obj(handle, obj);
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001509 spin_unlock(&class->lock);
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001510
Minchan Kim48b48002016-07-26 15:23:31 -07001511 return handle;
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001512 }
1513
Minchan Kim48b48002016-07-26 15:23:31 -07001514 spin_unlock(&class->lock);
1515
1516 zspage = alloc_zspage(pool, class, gfp);
1517 if (!zspage) {
1518 cache_free_handle(pool, handle);
1519 return 0;
1520 }
1521
1522 spin_lock(&class->lock);
Minchan Kim37836892016-07-26 15:23:23 -07001523 obj = obj_malloc(class, zspage, handle);
Minchan Kim48b48002016-07-26 15:23:31 -07001524 newfg = get_fullness_group(class, zspage);
1525 insert_zspage(class, zspage, newfg);
1526 set_zspage_mapping(zspage, class->index, newfg);
Minchan Kim2e40e162015-04-15 16:15:23 -07001527 record_obj(handle, obj);
Minchan Kim48b48002016-07-26 15:23:31 -07001528 atomic_long_add(class->pages_per_zspage,
1529 &pool->pages_allocated);
Ganesh Mahendranb4fd07a2016-07-28 15:47:49 -07001530 zs_stat_inc(class, OBJ_ALLOCATED, class->objs_per_zspage);
Minchan Kim48b48002016-07-26 15:23:31 -07001531
1532 /* We completely set up zspage so mark them as movable */
1533 SetZsPageMovable(pool, zspage);
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001534 spin_unlock(&class->lock);
1535
Minchan Kim2e40e162015-04-15 16:15:23 -07001536 return handle;
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001537}
1538EXPORT_SYMBOL_GPL(zs_malloc);
1539
Minchan Kim1ee47162016-05-20 16:59:45 -07001540static void obj_free(struct size_class *class, unsigned long obj)
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001541{
1542 struct link_free *link;
Minchan Kim37836892016-07-26 15:23:23 -07001543 struct zspage *zspage;
1544 struct page *f_page;
Minchan Kimbfd093f2016-07-26 15:23:28 -07001545 unsigned long f_offset;
1546 unsigned int f_objidx;
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001547 void *vaddr;
1548
Minchan Kim312fcae2015-04-15 16:15:30 -07001549 obj &= ~OBJ_ALLOCATED_TAG;
Minchan Kimc7806262015-04-15 16:15:26 -07001550 obj_to_location(obj, &f_page, &f_objidx);
Minchan Kimbfd093f2016-07-26 15:23:28 -07001551 f_offset = (class->size * f_objidx) & ~PAGE_MASK;
Minchan Kim37836892016-07-26 15:23:23 -07001552 zspage = get_zspage(f_page);
Minchan Kimc7806262015-04-15 16:15:26 -07001553
Minchan Kimc7806262015-04-15 16:15:26 -07001554 vaddr = kmap_atomic(f_page);
1555
1556 /* Insert this object in containing zspage's freelist */
1557 link = (struct link_free *)(vaddr + f_offset);
Minchan Kim3b1d9ca2016-07-26 15:23:37 -07001558 link->next = get_freeobj(zspage) << OBJ_TAG_BITS;
Minchan Kimc7806262015-04-15 16:15:26 -07001559 kunmap_atomic(vaddr);
Minchan Kimbfd093f2016-07-26 15:23:28 -07001560 set_freeobj(zspage, f_objidx);
Minchan Kim37836892016-07-26 15:23:23 -07001561 mod_zspage_inuse(zspage, -1);
Minchan Kimc7806262015-04-15 16:15:26 -07001562 zs_stat_dec(class, OBJ_USED, 1);
1563}
1564
1565void zs_free(struct zs_pool *pool, unsigned long handle)
1566{
Minchan Kim37836892016-07-26 15:23:23 -07001567 struct zspage *zspage;
1568 struct page *f_page;
Minchan Kimbfd093f2016-07-26 15:23:28 -07001569 unsigned long obj;
1570 unsigned int f_objidx;
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001571 int class_idx;
1572 struct size_class *class;
1573 enum fullness_group fullness;
Minchan Kim48b48002016-07-26 15:23:31 -07001574 bool isolated;
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001575
Minchan Kim2e40e162015-04-15 16:15:23 -07001576 if (unlikely(!handle))
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001577 return;
1578
Minchan Kim312fcae2015-04-15 16:15:30 -07001579 pin_tag(handle);
Minchan Kim2e40e162015-04-15 16:15:23 -07001580 obj = handle_to_obj(handle);
Minchan Kim2e40e162015-04-15 16:15:23 -07001581 obj_to_location(obj, &f_page, &f_objidx);
Minchan Kim37836892016-07-26 15:23:23 -07001582 zspage = get_zspage(f_page);
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001583
Minchan Kim48b48002016-07-26 15:23:31 -07001584 migrate_read_lock(zspage);
1585
Minchan Kim37836892016-07-26 15:23:23 -07001586 get_zspage_mapping(zspage, &class_idx, &fullness);
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001587 class = pool->size_class[class_idx];
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001588
1589 spin_lock(&class->lock);
Minchan Kim1ee47162016-05-20 16:59:45 -07001590 obj_free(class, obj);
Minchan Kim37836892016-07-26 15:23:23 -07001591 fullness = fix_fullness_group(class, zspage);
Minchan Kim48b48002016-07-26 15:23:31 -07001592 if (fullness != ZS_EMPTY) {
1593 migrate_read_unlock(zspage);
1594 goto out;
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001595 }
Minchan Kim48b48002016-07-26 15:23:31 -07001596
1597 isolated = is_zspage_isolated(zspage);
1598 migrate_read_unlock(zspage);
1599 /* If zspage is isolated, zs_page_putback will free the zspage */
1600 if (likely(!isolated))
1601 free_zspage(pool, class, zspage);
1602out:
1603
Minchan Kim312fcae2015-04-15 16:15:30 -07001604 spin_unlock(&class->lock);
1605 unpin_tag(handle);
Minchan Kim37836892016-07-26 15:23:23 -07001606 cache_free_handle(pool, handle);
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08001607}
1608EXPORT_SYMBOL_GPL(zs_free);
1609
Minchan Kim251cbb92016-05-20 16:59:42 -07001610static void zs_object_copy(struct size_class *class, unsigned long dst,
1611 unsigned long src)
Minchan Kim312fcae2015-04-15 16:15:30 -07001612{
1613 struct page *s_page, *d_page;
Minchan Kimbfd093f2016-07-26 15:23:28 -07001614 unsigned int s_objidx, d_objidx;
Minchan Kim312fcae2015-04-15 16:15:30 -07001615 unsigned long s_off, d_off;
1616 void *s_addr, *d_addr;
1617 int s_size, d_size, size;
1618 int written = 0;
1619
1620 s_size = d_size = class->size;
1621
1622 obj_to_location(src, &s_page, &s_objidx);
1623 obj_to_location(dst, &d_page, &d_objidx);
1624
Minchan Kimbfd093f2016-07-26 15:23:28 -07001625 s_off = (class->size * s_objidx) & ~PAGE_MASK;
1626 d_off = (class->size * d_objidx) & ~PAGE_MASK;
Minchan Kim312fcae2015-04-15 16:15:30 -07001627
1628 if (s_off + class->size > PAGE_SIZE)
1629 s_size = PAGE_SIZE - s_off;
1630
1631 if (d_off + class->size > PAGE_SIZE)
1632 d_size = PAGE_SIZE - d_off;
1633
1634 s_addr = kmap_atomic(s_page);
1635 d_addr = kmap_atomic(d_page);
1636
1637 while (1) {
1638 size = min(s_size, d_size);
1639 memcpy(d_addr + d_off, s_addr + s_off, size);
1640 written += size;
1641
1642 if (written == class->size)
1643 break;
1644
Sergey Senozhatsky495819e2015-04-15 16:16:15 -07001645 s_off += size;
1646 s_size -= size;
1647 d_off += size;
1648 d_size -= size;
1649
1650 if (s_off >= PAGE_SIZE) {
Minchan Kim312fcae2015-04-15 16:15:30 -07001651 kunmap_atomic(d_addr);
1652 kunmap_atomic(s_addr);
1653 s_page = get_next_page(s_page);
Minchan Kim312fcae2015-04-15 16:15:30 -07001654 s_addr = kmap_atomic(s_page);
1655 d_addr = kmap_atomic(d_page);
1656 s_size = class->size - written;
1657 s_off = 0;
Minchan Kim312fcae2015-04-15 16:15:30 -07001658 }
1659
Sergey Senozhatsky495819e2015-04-15 16:16:15 -07001660 if (d_off >= PAGE_SIZE) {
Minchan Kim312fcae2015-04-15 16:15:30 -07001661 kunmap_atomic(d_addr);
1662 d_page = get_next_page(d_page);
Minchan Kim312fcae2015-04-15 16:15:30 -07001663 d_addr = kmap_atomic(d_page);
1664 d_size = class->size - written;
1665 d_off = 0;
Minchan Kim312fcae2015-04-15 16:15:30 -07001666 }
1667 }
1668
1669 kunmap_atomic(d_addr);
1670 kunmap_atomic(s_addr);
1671}
1672
1673/*
1674 * Find alloced object in zspage from index object and
1675 * return handle.
1676 */
Minchan Kim251cbb92016-05-20 16:59:42 -07001677static unsigned long find_alloced_obj(struct size_class *class,
Ganesh Mahendrancf675acb2016-07-28 15:47:46 -07001678 struct page *page, int *obj_idx)
Minchan Kim312fcae2015-04-15 16:15:30 -07001679{
1680 unsigned long head;
1681 int offset = 0;
Ganesh Mahendrancf675acb2016-07-28 15:47:46 -07001682 int index = *obj_idx;
Minchan Kim312fcae2015-04-15 16:15:30 -07001683 unsigned long handle = 0;
1684 void *addr = kmap_atomic(page);
1685
Minchan Kim37836892016-07-26 15:23:23 -07001686 offset = get_first_obj_offset(page);
Minchan Kim312fcae2015-04-15 16:15:30 -07001687 offset += class->size * index;
1688
1689 while (offset < PAGE_SIZE) {
Minchan Kim48b48002016-07-26 15:23:31 -07001690 head = obj_to_head(page, addr + offset);
Minchan Kim312fcae2015-04-15 16:15:30 -07001691 if (head & OBJ_ALLOCATED_TAG) {
1692 handle = head & ~OBJ_ALLOCATED_TAG;
1693 if (trypin_tag(handle))
1694 break;
1695 handle = 0;
1696 }
1697
1698 offset += class->size;
1699 index++;
1700 }
1701
1702 kunmap_atomic(addr);
Ganesh Mahendrancf675acb2016-07-28 15:47:46 -07001703
1704 *obj_idx = index;
1705
Minchan Kim312fcae2015-04-15 16:15:30 -07001706 return handle;
1707}
1708
1709struct zs_compact_control {
Minchan Kim37836892016-07-26 15:23:23 -07001710 /* Source spage for migration which could be a subpage of zspage */
Minchan Kim312fcae2015-04-15 16:15:30 -07001711 struct page *s_page;
1712 /* Destination page for migration which should be a first page
1713 * of zspage. */
1714 struct page *d_page;
1715 /* Starting object index within @s_page which used for live object
1716 * in the subpage. */
Ganesh Mahendran41b88e12016-07-28 15:47:43 -07001717 int obj_idx;
Minchan Kim312fcae2015-04-15 16:15:30 -07001718};
1719
1720static int migrate_zspage(struct zs_pool *pool, struct size_class *class,
1721 struct zs_compact_control *cc)
1722{
1723 unsigned long used_obj, free_obj;
1724 unsigned long handle;
1725 struct page *s_page = cc->s_page;
1726 struct page *d_page = cc->d_page;
Ganesh Mahendran41b88e12016-07-28 15:47:43 -07001727 int obj_idx = cc->obj_idx;
Minchan Kim312fcae2015-04-15 16:15:30 -07001728 int ret = 0;
1729
1730 while (1) {
Ganesh Mahendrancf675acb2016-07-28 15:47:46 -07001731 handle = find_alloced_obj(class, s_page, &obj_idx);
Minchan Kim312fcae2015-04-15 16:15:30 -07001732 if (!handle) {
1733 s_page = get_next_page(s_page);
1734 if (!s_page)
1735 break;
Ganesh Mahendran41b88e12016-07-28 15:47:43 -07001736 obj_idx = 0;
Minchan Kim312fcae2015-04-15 16:15:30 -07001737 continue;
1738 }
1739
1740 /* Stop if there is no more space */
Minchan Kim37836892016-07-26 15:23:23 -07001741 if (zspage_full(class, get_zspage(d_page))) {
Minchan Kim312fcae2015-04-15 16:15:30 -07001742 unpin_tag(handle);
1743 ret = -ENOMEM;
1744 break;
1745 }
1746
1747 used_obj = handle_to_obj(handle);
Minchan Kim37836892016-07-26 15:23:23 -07001748 free_obj = obj_malloc(class, get_zspage(d_page), handle);
Minchan Kim251cbb92016-05-20 16:59:42 -07001749 zs_object_copy(class, free_obj, used_obj);
Ganesh Mahendran41b88e12016-07-28 15:47:43 -07001750 obj_idx++;
Junil Leec102f07c2016-01-20 14:58:18 -08001751 /*
1752 * record_obj updates handle's value to free_obj and it will
1753 * invalidate lock bit(ie, HANDLE_PIN_BIT) of handle, which
1754 * breaks synchronization using pin_tag(e,g, zs_free) so
1755 * let's keep the lock bit.
1756 */
1757 free_obj |= BIT(HANDLE_PIN_BIT);
Minchan Kim312fcae2015-04-15 16:15:30 -07001758 record_obj(handle, free_obj);
1759 unpin_tag(handle);
Minchan Kim1ee47162016-05-20 16:59:45 -07001760 obj_free(class, used_obj);
Minchan Kim312fcae2015-04-15 16:15:30 -07001761 }
1762
1763 /* Remember last position in this iteration */
1764 cc->s_page = s_page;
Ganesh Mahendran41b88e12016-07-28 15:47:43 -07001765 cc->obj_idx = obj_idx;
Minchan Kim312fcae2015-04-15 16:15:30 -07001766
1767 return ret;
1768}
1769
Minchan Kim37836892016-07-26 15:23:23 -07001770static struct zspage *isolate_zspage(struct size_class *class, bool source)
Minchan Kim312fcae2015-04-15 16:15:30 -07001771{
1772 int i;
Minchan Kim37836892016-07-26 15:23:23 -07001773 struct zspage *zspage;
1774 enum fullness_group fg[2] = {ZS_ALMOST_EMPTY, ZS_ALMOST_FULL};
Minchan Kim312fcae2015-04-15 16:15:30 -07001775
Minchan Kim37836892016-07-26 15:23:23 -07001776 if (!source) {
1777 fg[0] = ZS_ALMOST_FULL;
1778 fg[1] = ZS_ALMOST_EMPTY;
1779 }
1780
1781 for (i = 0; i < 2; i++) {
1782 zspage = list_first_entry_or_null(&class->fullness_list[fg[i]],
1783 struct zspage, list);
1784 if (zspage) {
Minchan Kim48b48002016-07-26 15:23:31 -07001785 VM_BUG_ON(is_zspage_isolated(zspage));
Minchan Kim37836892016-07-26 15:23:23 -07001786 remove_zspage(class, zspage, fg[i]);
1787 return zspage;
Minchan Kim312fcae2015-04-15 16:15:30 -07001788 }
1789 }
1790
Minchan Kim37836892016-07-26 15:23:23 -07001791 return zspage;
Minchan Kim312fcae2015-04-15 16:15:30 -07001792}
1793
Sergey Senozhatsky860c7072015-09-08 15:04:38 -07001794/*
Minchan Kim37836892016-07-26 15:23:23 -07001795 * putback_zspage - add @zspage into right class's fullness list
Sergey Senozhatsky860c7072015-09-08 15:04:38 -07001796 * @class: destination class
Minchan Kim37836892016-07-26 15:23:23 -07001797 * @zspage: target page
Sergey Senozhatsky860c7072015-09-08 15:04:38 -07001798 *
Minchan Kim37836892016-07-26 15:23:23 -07001799 * Return @zspage's fullness_group
Sergey Senozhatsky860c7072015-09-08 15:04:38 -07001800 */
Minchan Kim4aa409c2016-07-26 15:23:26 -07001801static enum fullness_group putback_zspage(struct size_class *class,
Minchan Kim37836892016-07-26 15:23:23 -07001802 struct zspage *zspage)
Minchan Kim312fcae2015-04-15 16:15:30 -07001803{
Minchan Kim312fcae2015-04-15 16:15:30 -07001804 enum fullness_group fullness;
1805
Minchan Kim48b48002016-07-26 15:23:31 -07001806 VM_BUG_ON(is_zspage_isolated(zspage));
1807
Minchan Kim37836892016-07-26 15:23:23 -07001808 fullness = get_fullness_group(class, zspage);
1809 insert_zspage(class, zspage, fullness);
1810 set_zspage_mapping(zspage, class->index, fullness);
Minchan Kim839373e2015-04-15 16:16:18 -07001811
Sergey Senozhatsky860c7072015-09-08 15:04:38 -07001812 return fullness;
Minchan Kim312fcae2015-04-15 16:15:30 -07001813}
1814
Minchan Kim48b48002016-07-26 15:23:31 -07001815#ifdef CONFIG_COMPACTION
1816static struct dentry *zs_mount(struct file_system_type *fs_type,
1817 int flags, const char *dev_name, void *data)
1818{
1819 static const struct dentry_operations ops = {
1820 .d_dname = simple_dname,
1821 };
1822
1823 return mount_pseudo(fs_type, "zsmalloc:", NULL, &ops, ZSMALLOC_MAGIC);
1824}
1825
1826static struct file_system_type zsmalloc_fs = {
1827 .name = "zsmalloc",
1828 .mount = zs_mount,
1829 .kill_sb = kill_anon_super,
1830};
1831
1832static int zsmalloc_mount(void)
1833{
1834 int ret = 0;
1835
1836 zsmalloc_mnt = kern_mount(&zsmalloc_fs);
1837 if (IS_ERR(zsmalloc_mnt))
1838 ret = PTR_ERR(zsmalloc_mnt);
1839
1840 return ret;
1841}
1842
1843static void zsmalloc_unmount(void)
1844{
1845 kern_unmount(zsmalloc_mnt);
1846}
1847
1848static void migrate_lock_init(struct zspage *zspage)
1849{
1850 rwlock_init(&zspage->lock);
1851}
1852
1853static void migrate_read_lock(struct zspage *zspage)
1854{
1855 read_lock(&zspage->lock);
1856}
1857
1858static void migrate_read_unlock(struct zspage *zspage)
1859{
1860 read_unlock(&zspage->lock);
1861}
1862
1863static void migrate_write_lock(struct zspage *zspage)
1864{
1865 write_lock(&zspage->lock);
1866}
1867
1868static void migrate_write_unlock(struct zspage *zspage)
1869{
1870 write_unlock(&zspage->lock);
1871}
1872
1873/* Number of isolated subpage for *page migration* in this zspage */
1874static void inc_zspage_isolation(struct zspage *zspage)
1875{
1876 zspage->isolated++;
1877}
1878
1879static void dec_zspage_isolation(struct zspage *zspage)
1880{
1881 zspage->isolated--;
1882}
1883
1884static void replace_sub_page(struct size_class *class, struct zspage *zspage,
1885 struct page *newpage, struct page *oldpage)
1886{
1887 struct page *page;
1888 struct page *pages[ZS_MAX_PAGES_PER_ZSPAGE] = {NULL, };
1889 int idx = 0;
1890
1891 page = get_first_page(zspage);
1892 do {
1893 if (page == oldpage)
1894 pages[idx] = newpage;
1895 else
1896 pages[idx] = page;
1897 idx++;
1898 } while ((page = get_next_page(page)) != NULL);
1899
1900 create_page_chain(class, zspage, pages);
1901 set_first_obj_offset(newpage, get_first_obj_offset(oldpage));
1902 if (unlikely(PageHugeObject(oldpage)))
1903 newpage->index = oldpage->index;
1904 __SetPageMovable(newpage, page_mapping(oldpage));
1905}
1906
1907bool zs_page_isolate(struct page *page, isolate_mode_t mode)
1908{
1909 struct zs_pool *pool;
1910 struct size_class *class;
1911 int class_idx;
1912 enum fullness_group fullness;
1913 struct zspage *zspage;
1914 struct address_space *mapping;
1915
1916 /*
1917 * Page is locked so zspage couldn't be destroyed. For detail, look at
1918 * lock_zspage in free_zspage.
1919 */
1920 VM_BUG_ON_PAGE(!PageMovable(page), page);
1921 VM_BUG_ON_PAGE(PageIsolated(page), page);
1922
1923 zspage = get_zspage(page);
1924
1925 /*
1926 * Without class lock, fullness could be stale while class_idx is okay
1927 * because class_idx is constant unless page is freed so we should get
1928 * fullness again under class lock.
1929 */
1930 get_zspage_mapping(zspage, &class_idx, &fullness);
1931 mapping = page_mapping(page);
1932 pool = mapping->private_data;
1933 class = pool->size_class[class_idx];
1934
1935 spin_lock(&class->lock);
1936 if (get_zspage_inuse(zspage) == 0) {
1937 spin_unlock(&class->lock);
1938 return false;
1939 }
1940
1941 /* zspage is isolated for object migration */
1942 if (list_empty(&zspage->list) && !is_zspage_isolated(zspage)) {
1943 spin_unlock(&class->lock);
1944 return false;
1945 }
1946
1947 /*
1948 * If this is first time isolation for the zspage, isolate zspage from
1949 * size_class to prevent further object allocation from the zspage.
1950 */
1951 if (!list_empty(&zspage->list) && !is_zspage_isolated(zspage)) {
1952 get_zspage_mapping(zspage, &class_idx, &fullness);
1953 remove_zspage(class, zspage, fullness);
1954 }
1955
1956 inc_zspage_isolation(zspage);
1957 spin_unlock(&class->lock);
1958
1959 return true;
1960}
1961
1962int zs_page_migrate(struct address_space *mapping, struct page *newpage,
1963 struct page *page, enum migrate_mode mode)
1964{
1965 struct zs_pool *pool;
1966 struct size_class *class;
1967 int class_idx;
1968 enum fullness_group fullness;
1969 struct zspage *zspage;
1970 struct page *dummy;
1971 void *s_addr, *d_addr, *addr;
1972 int offset, pos;
1973 unsigned long handle, head;
1974 unsigned long old_obj, new_obj;
1975 unsigned int obj_idx;
1976 int ret = -EAGAIN;
1977
Jérôme Glisse2916ecc2017-09-08 16:12:06 -07001978 /*
1979 * We cannot support the _NO_COPY case here, because copy needs to
1980 * happen under the zs lock, which does not work with
1981 * MIGRATE_SYNC_NO_COPY workflow.
1982 */
1983 if (mode == MIGRATE_SYNC_NO_COPY)
1984 return -EINVAL;
1985
Minchan Kim48b48002016-07-26 15:23:31 -07001986 VM_BUG_ON_PAGE(!PageMovable(page), page);
1987 VM_BUG_ON_PAGE(!PageIsolated(page), page);
1988
1989 zspage = get_zspage(page);
1990
1991 /* Concurrent compactor cannot migrate any subpage in zspage */
1992 migrate_write_lock(zspage);
1993 get_zspage_mapping(zspage, &class_idx, &fullness);
1994 pool = mapping->private_data;
1995 class = pool->size_class[class_idx];
1996 offset = get_first_obj_offset(page);
1997
1998 spin_lock(&class->lock);
1999 if (!get_zspage_inuse(zspage)) {
Hui Zhu77ff4652017-09-06 16:21:08 -07002000 /*
2001 * Set "offset" to end of the page so that every loops
2002 * skips unnecessary object scanning.
2003 */
2004 offset = PAGE_SIZE;
Minchan Kim48b48002016-07-26 15:23:31 -07002005 }
2006
2007 pos = offset;
2008 s_addr = kmap_atomic(page);
2009 while (pos < PAGE_SIZE) {
2010 head = obj_to_head(page, s_addr + pos);
2011 if (head & OBJ_ALLOCATED_TAG) {
2012 handle = head & ~OBJ_ALLOCATED_TAG;
2013 if (!trypin_tag(handle))
2014 goto unpin_objects;
2015 }
2016 pos += class->size;
2017 }
2018
2019 /*
2020 * Here, any user cannot access all objects in the zspage so let's move.
2021 */
2022 d_addr = kmap_atomic(newpage);
2023 memcpy(d_addr, s_addr, PAGE_SIZE);
2024 kunmap_atomic(d_addr);
2025
2026 for (addr = s_addr + offset; addr < s_addr + pos;
2027 addr += class->size) {
2028 head = obj_to_head(page, addr);
2029 if (head & OBJ_ALLOCATED_TAG) {
2030 handle = head & ~OBJ_ALLOCATED_TAG;
2031 if (!testpin_tag(handle))
2032 BUG();
2033
2034 old_obj = handle_to_obj(handle);
2035 obj_to_location(old_obj, &dummy, &obj_idx);
2036 new_obj = (unsigned long)location_to_obj(newpage,
2037 obj_idx);
2038 new_obj |= BIT(HANDLE_PIN_BIT);
2039 record_obj(handle, new_obj);
2040 }
2041 }
2042
2043 replace_sub_page(class, zspage, newpage, page);
2044 get_page(newpage);
2045
2046 dec_zspage_isolation(zspage);
2047
2048 /*
2049 * Page migration is done so let's putback isolated zspage to
2050 * the list if @page is final isolated subpage in the zspage.
2051 */
2052 if (!is_zspage_isolated(zspage))
2053 putback_zspage(class, zspage);
2054
2055 reset_page(page);
2056 put_page(page);
2057 page = newpage;
2058
Minchan Kimdd4123f2016-07-26 15:26:50 -07002059 ret = MIGRATEPAGE_SUCCESS;
Minchan Kim48b48002016-07-26 15:23:31 -07002060unpin_objects:
2061 for (addr = s_addr + offset; addr < s_addr + pos;
2062 addr += class->size) {
2063 head = obj_to_head(page, addr);
2064 if (head & OBJ_ALLOCATED_TAG) {
2065 handle = head & ~OBJ_ALLOCATED_TAG;
2066 if (!testpin_tag(handle))
2067 BUG();
2068 unpin_tag(handle);
2069 }
2070 }
2071 kunmap_atomic(s_addr);
Minchan Kim48b48002016-07-26 15:23:31 -07002072 spin_unlock(&class->lock);
2073 migrate_write_unlock(zspage);
2074
2075 return ret;
2076}
2077
2078void zs_page_putback(struct page *page)
2079{
2080 struct zs_pool *pool;
2081 struct size_class *class;
2082 int class_idx;
2083 enum fullness_group fg;
2084 struct address_space *mapping;
2085 struct zspage *zspage;
2086
2087 VM_BUG_ON_PAGE(!PageMovable(page), page);
2088 VM_BUG_ON_PAGE(!PageIsolated(page), page);
2089
2090 zspage = get_zspage(page);
2091 get_zspage_mapping(zspage, &class_idx, &fg);
2092 mapping = page_mapping(page);
2093 pool = mapping->private_data;
2094 class = pool->size_class[class_idx];
2095
2096 spin_lock(&class->lock);
2097 dec_zspage_isolation(zspage);
2098 if (!is_zspage_isolated(zspage)) {
2099 fg = putback_zspage(class, zspage);
2100 /*
2101 * Due to page_lock, we cannot free zspage immediately
2102 * so let's defer.
2103 */
2104 if (fg == ZS_EMPTY)
2105 schedule_work(&pool->free_work);
2106 }
2107 spin_unlock(&class->lock);
2108}
2109
2110const struct address_space_operations zsmalloc_aops = {
2111 .isolate_page = zs_page_isolate,
2112 .migratepage = zs_page_migrate,
2113 .putback_page = zs_page_putback,
2114};
2115
2116static int zs_register_migration(struct zs_pool *pool)
2117{
2118 pool->inode = alloc_anon_inode(zsmalloc_mnt->mnt_sb);
2119 if (IS_ERR(pool->inode)) {
2120 pool->inode = NULL;
2121 return 1;
2122 }
2123
2124 pool->inode->i_mapping->private_data = pool;
2125 pool->inode->i_mapping->a_ops = &zsmalloc_aops;
2126 return 0;
2127}
2128
2129static void zs_unregister_migration(struct zs_pool *pool)
2130{
2131 flush_work(&pool->free_work);
Markus Elfringc3491ec2016-07-28 15:48:59 -07002132 iput(pool->inode);
Minchan Kim48b48002016-07-26 15:23:31 -07002133}
2134
2135/*
2136 * Caller should hold page_lock of all pages in the zspage
2137 * In here, we cannot use zspage meta data.
2138 */
2139static void async_free_zspage(struct work_struct *work)
2140{
2141 int i;
2142 struct size_class *class;
2143 unsigned int class_idx;
2144 enum fullness_group fullness;
2145 struct zspage *zspage, *tmp;
2146 LIST_HEAD(free_pages);
2147 struct zs_pool *pool = container_of(work, struct zs_pool,
2148 free_work);
2149
Jerome Marchandcf8e0fed2017-07-10 15:50:18 -07002150 for (i = 0; i < ZS_SIZE_CLASSES; i++) {
Minchan Kim48b48002016-07-26 15:23:31 -07002151 class = pool->size_class[i];
2152 if (class->index != i)
2153 continue;
2154
2155 spin_lock(&class->lock);
2156 list_splice_init(&class->fullness_list[ZS_EMPTY], &free_pages);
2157 spin_unlock(&class->lock);
2158 }
2159
2160
2161 list_for_each_entry_safe(zspage, tmp, &free_pages, list) {
2162 list_del(&zspage->list);
2163 lock_zspage(zspage);
2164
2165 get_zspage_mapping(zspage, &class_idx, &fullness);
2166 VM_BUG_ON(fullness != ZS_EMPTY);
2167 class = pool->size_class[class_idx];
2168 spin_lock(&class->lock);
2169 __free_zspage(pool, pool->size_class[class_idx], zspage);
2170 spin_unlock(&class->lock);
2171 }
2172};
2173
2174static void kick_deferred_free(struct zs_pool *pool)
2175{
2176 schedule_work(&pool->free_work);
2177}
2178
2179static void init_deferred_free(struct zs_pool *pool)
2180{
2181 INIT_WORK(&pool->free_work, async_free_zspage);
2182}
2183
2184static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage)
2185{
2186 struct page *page = get_first_page(zspage);
2187
2188 do {
2189 WARN_ON(!trylock_page(page));
2190 __SetPageMovable(page, pool->inode->i_mapping);
2191 unlock_page(page);
2192 } while ((page = get_next_page(page)) != NULL);
2193}
2194#endif
2195
Sergey Senozhatsky04f05902015-09-08 15:04:30 -07002196/*
2197 *
2198 * Based on the number of unused allocated objects calculate
2199 * and return the number of pages that we can free.
Sergey Senozhatsky04f05902015-09-08 15:04:30 -07002200 */
2201static unsigned long zs_can_compact(struct size_class *class)
2202{
2203 unsigned long obj_wasted;
Sergey Senozhatsky44f43e92016-05-09 16:28:49 -07002204 unsigned long obj_allocated = zs_stat_get(class, OBJ_ALLOCATED);
2205 unsigned long obj_used = zs_stat_get(class, OBJ_USED);
Sergey Senozhatsky04f05902015-09-08 15:04:30 -07002206
Sergey Senozhatsky44f43e92016-05-09 16:28:49 -07002207 if (obj_allocated <= obj_used)
2208 return 0;
Sergey Senozhatsky04f05902015-09-08 15:04:30 -07002209
Sergey Senozhatsky44f43e92016-05-09 16:28:49 -07002210 obj_wasted = obj_allocated - obj_used;
Ganesh Mahendranb4fd07a2016-07-28 15:47:49 -07002211 obj_wasted /= class->objs_per_zspage;
Sergey Senozhatsky04f05902015-09-08 15:04:30 -07002212
Minchan Kim6cbf16b2015-09-08 15:04:49 -07002213 return obj_wasted * class->pages_per_zspage;
Sergey Senozhatsky04f05902015-09-08 15:04:30 -07002214}
2215
Sergey Senozhatsky7d3f3932015-09-08 15:04:35 -07002216static void __zs_compact(struct zs_pool *pool, struct size_class *class)
Minchan Kim312fcae2015-04-15 16:15:30 -07002217{
Minchan Kim312fcae2015-04-15 16:15:30 -07002218 struct zs_compact_control cc;
Minchan Kim37836892016-07-26 15:23:23 -07002219 struct zspage *src_zspage;
2220 struct zspage *dst_zspage = NULL;
Minchan Kim312fcae2015-04-15 16:15:30 -07002221
Minchan Kim312fcae2015-04-15 16:15:30 -07002222 spin_lock(&class->lock);
Minchan Kim37836892016-07-26 15:23:23 -07002223 while ((src_zspage = isolate_zspage(class, true))) {
Minchan Kim312fcae2015-04-15 16:15:30 -07002224
Sergey Senozhatsky04f05902015-09-08 15:04:30 -07002225 if (!zs_can_compact(class))
2226 break;
2227
Ganesh Mahendran41b88e12016-07-28 15:47:43 -07002228 cc.obj_idx = 0;
Minchan Kim48b48002016-07-26 15:23:31 -07002229 cc.s_page = get_first_page(src_zspage);
Minchan Kim312fcae2015-04-15 16:15:30 -07002230
Minchan Kim37836892016-07-26 15:23:23 -07002231 while ((dst_zspage = isolate_zspage(class, false))) {
Minchan Kim48b48002016-07-26 15:23:31 -07002232 cc.d_page = get_first_page(dst_zspage);
Minchan Kim312fcae2015-04-15 16:15:30 -07002233 /*
Sergey Senozhatsky0dc63d482015-09-08 15:04:33 -07002234 * If there is no more space in dst_page, resched
2235 * and see if anyone had allocated another zspage.
Minchan Kim312fcae2015-04-15 16:15:30 -07002236 */
2237 if (!migrate_zspage(pool, class, &cc))
2238 break;
2239
Minchan Kim4aa409c2016-07-26 15:23:26 -07002240 putback_zspage(class, dst_zspage);
Minchan Kim312fcae2015-04-15 16:15:30 -07002241 }
2242
2243 /* Stop if we couldn't find slot */
Minchan Kim37836892016-07-26 15:23:23 -07002244 if (dst_zspage == NULL)
Minchan Kim312fcae2015-04-15 16:15:30 -07002245 break;
2246
Minchan Kim4aa409c2016-07-26 15:23:26 -07002247 putback_zspage(class, dst_zspage);
2248 if (putback_zspage(class, src_zspage) == ZS_EMPTY) {
Minchan Kim48b48002016-07-26 15:23:31 -07002249 free_zspage(pool, class, src_zspage);
Minchan Kim6cbf16b2015-09-08 15:04:49 -07002250 pool->stats.pages_compacted += class->pages_per_zspage;
Minchan Kim4aa409c2016-07-26 15:23:26 -07002251 }
Minchan Kim312fcae2015-04-15 16:15:30 -07002252 spin_unlock(&class->lock);
Minchan Kim312fcae2015-04-15 16:15:30 -07002253 cond_resched();
2254 spin_lock(&class->lock);
2255 }
2256
Minchan Kim37836892016-07-26 15:23:23 -07002257 if (src_zspage)
Minchan Kim4aa409c2016-07-26 15:23:26 -07002258 putback_zspage(class, src_zspage);
Minchan Kim312fcae2015-04-15 16:15:30 -07002259
Sergey Senozhatsky7d3f3932015-09-08 15:04:35 -07002260 spin_unlock(&class->lock);
Minchan Kim312fcae2015-04-15 16:15:30 -07002261}
2262
2263unsigned long zs_compact(struct zs_pool *pool)
2264{
2265 int i;
Minchan Kim312fcae2015-04-15 16:15:30 -07002266 struct size_class *class;
2267
Jerome Marchandcf8e0fed2017-07-10 15:50:18 -07002268 for (i = ZS_SIZE_CLASSES - 1; i >= 0; i--) {
Minchan Kim312fcae2015-04-15 16:15:30 -07002269 class = pool->size_class[i];
2270 if (!class)
2271 continue;
2272 if (class->index != i)
2273 continue;
Sergey Senozhatsky7d3f3932015-09-08 15:04:35 -07002274 __zs_compact(pool, class);
Minchan Kim312fcae2015-04-15 16:15:30 -07002275 }
2276
Sergey Senozhatsky860c7072015-09-08 15:04:38 -07002277 return pool->stats.pages_compacted;
Minchan Kim312fcae2015-04-15 16:15:30 -07002278}
2279EXPORT_SYMBOL_GPL(zs_compact);
2280
Sergey Senozhatsky7d3f3932015-09-08 15:04:35 -07002281void zs_pool_stats(struct zs_pool *pool, struct zs_pool_stats *stats)
2282{
2283 memcpy(stats, &pool->stats, sizeof(struct zs_pool_stats));
2284}
2285EXPORT_SYMBOL_GPL(zs_pool_stats);
2286
Sergey Senozhatskyab9d3062015-09-08 15:04:41 -07002287static unsigned long zs_shrinker_scan(struct shrinker *shrinker,
2288 struct shrink_control *sc)
2289{
2290 unsigned long pages_freed;
2291 struct zs_pool *pool = container_of(shrinker, struct zs_pool,
2292 shrinker);
2293
2294 pages_freed = pool->stats.pages_compacted;
2295 /*
2296 * Compact classes and calculate compaction delta.
2297 * Can run concurrently with a manually triggered
2298 * (by user) compaction.
2299 */
2300 pages_freed = zs_compact(pool) - pages_freed;
2301
2302 return pages_freed ? pages_freed : SHRINK_STOP;
2303}
2304
2305static unsigned long zs_shrinker_count(struct shrinker *shrinker,
2306 struct shrink_control *sc)
2307{
2308 int i;
2309 struct size_class *class;
2310 unsigned long pages_to_free = 0;
2311 struct zs_pool *pool = container_of(shrinker, struct zs_pool,
2312 shrinker);
2313
Jerome Marchandcf8e0fed2017-07-10 15:50:18 -07002314 for (i = ZS_SIZE_CLASSES - 1; i >= 0; i--) {
Sergey Senozhatskyab9d3062015-09-08 15:04:41 -07002315 class = pool->size_class[i];
2316 if (!class)
2317 continue;
2318 if (class->index != i)
2319 continue;
2320
Sergey Senozhatskyab9d3062015-09-08 15:04:41 -07002321 pages_to_free += zs_can_compact(class);
Sergey Senozhatskyab9d3062015-09-08 15:04:41 -07002322 }
2323
2324 return pages_to_free;
2325}
2326
2327static void zs_unregister_shrinker(struct zs_pool *pool)
2328{
Aliaksei Karaliou93144ca2018-01-31 16:18:40 -08002329 unregister_shrinker(&pool->shrinker);
Sergey Senozhatskyab9d3062015-09-08 15:04:41 -07002330}
2331
2332static int zs_register_shrinker(struct zs_pool *pool)
2333{
2334 pool->shrinker.scan_objects = zs_shrinker_scan;
2335 pool->shrinker.count_objects = zs_shrinker_count;
2336 pool->shrinker.batch = 0;
2337 pool->shrinker.seeks = DEFAULT_SEEKS;
2338
2339 return register_shrinker(&pool->shrinker);
2340}
2341
Davidlohr Bueso4bbc0bc2013-01-04 12:14:00 -08002342/**
2343 * zs_create_pool - Creates an allocation pool to work from.
Ganesh Mahendranfd854462016-07-28 15:47:54 -07002344 * @name: pool name to be created
Davidlohr Bueso4bbc0bc2013-01-04 12:14:00 -08002345 *
2346 * This function must be called before anything when using
2347 * the zsmalloc allocator.
2348 *
2349 * On success, a pointer to the newly created pool is returned,
2350 * otherwise NULL.
2351 */
Sergey Senozhatskyd0d8da22016-05-20 16:59:48 -07002352struct zs_pool *zs_create_pool(const char *name)
Nitin Gupta61989a82012-01-09 16:51:56 -06002353{
Ganesh Mahendran18136652014-12-12 16:57:10 -08002354 int i;
Nitin Gupta61989a82012-01-09 16:51:56 -06002355 struct zs_pool *pool;
Ganesh Mahendrandf8b5bb2014-12-12 16:57:07 -08002356 struct size_class *prev_class = NULL;
Nitin Gupta61989a82012-01-09 16:51:56 -06002357
Ganesh Mahendran18136652014-12-12 16:57:10 -08002358 pool = kzalloc(sizeof(*pool), GFP_KERNEL);
Nitin Gupta61989a82012-01-09 16:51:56 -06002359 if (!pool)
2360 return NULL;
2361
Minchan Kim48b48002016-07-26 15:23:31 -07002362 init_deferred_free(pool);
Ganesh Mahendran0f050d92015-02-12 15:00:54 -08002363
Minchan Kim2e40e162015-04-15 16:15:23 -07002364 pool->name = kstrdup(name, GFP_KERNEL);
2365 if (!pool->name)
2366 goto err;
2367
Minchan Kim37836892016-07-26 15:23:23 -07002368 if (create_cache(pool))
Minchan Kim2e40e162015-04-15 16:15:23 -07002369 goto err;
Mahendran Ganesh40f9fb82014-12-12 16:57:01 -08002370
Joonsoo Kim9eec4cd2014-12-12 16:56:44 -08002371 /*
Xishi Qiu399d8ee2017-02-22 15:45:01 -08002372 * Iterate reversely, because, size of size_class that we want to use
Joonsoo Kim9eec4cd2014-12-12 16:56:44 -08002373 * for merging should be larger or equal to current size.
2374 */
Jerome Marchandcf8e0fed2017-07-10 15:50:18 -07002375 for (i = ZS_SIZE_CLASSES - 1; i >= 0; i--) {
Nitin Gupta61989a82012-01-09 16:51:56 -06002376 int size;
Joonsoo Kim9eec4cd2014-12-12 16:56:44 -08002377 int pages_per_zspage;
Ganesh Mahendran64d90462016-07-28 15:47:51 -07002378 int objs_per_zspage;
Nitin Gupta61989a82012-01-09 16:51:56 -06002379 struct size_class *class;
Minchan Kim37836892016-07-26 15:23:23 -07002380 int fullness = 0;
Nitin Gupta61989a82012-01-09 16:51:56 -06002381
2382 size = ZS_MIN_ALLOC_SIZE + i * ZS_SIZE_CLASS_DELTA;
2383 if (size > ZS_MAX_ALLOC_SIZE)
2384 size = ZS_MAX_ALLOC_SIZE;
Joonsoo Kim9eec4cd2014-12-12 16:56:44 -08002385 pages_per_zspage = get_pages_per_zspage(size);
Ganesh Mahendran64d90462016-07-28 15:47:51 -07002386 objs_per_zspage = pages_per_zspage * PAGE_SIZE / size;
Nitin Gupta61989a82012-01-09 16:51:56 -06002387
Joonsoo Kim9eec4cd2014-12-12 16:56:44 -08002388 /*
Sergey Senozhatsky010b4952018-04-05 16:24:43 -07002389 * We iterate from biggest down to smallest classes,
2390 * so huge_class_size holds the size of the first huge
2391 * class. Any object bigger than or equal to that will
2392 * endup in the huge class.
2393 */
2394 if (pages_per_zspage != 1 && objs_per_zspage != 1 &&
2395 !huge_class_size) {
2396 huge_class_size = size;
2397 /*
2398 * The object uses ZS_HANDLE_SIZE bytes to store the
2399 * handle. We need to subtract it, because zs_malloc()
2400 * unconditionally adds handle size before it performs
2401 * size class search - so object may be smaller than
2402 * huge class size, yet it still can end up in the huge
2403 * class because it grows by ZS_HANDLE_SIZE extra bytes
2404 * right before class lookup.
2405 */
2406 huge_class_size -= (ZS_HANDLE_SIZE - 1);
2407 }
2408
2409 /*
Joonsoo Kim9eec4cd2014-12-12 16:56:44 -08002410 * size_class is used for normal zsmalloc operation such
2411 * as alloc/free for that size. Although it is natural that we
2412 * have one size_class for each size, there is a chance that we
2413 * can get more memory utilization if we use one size_class for
2414 * many different sizes whose size_class have same
2415 * characteristics. So, we makes size_class point to
2416 * previous size_class if possible.
2417 */
Ganesh Mahendrandf8b5bb2014-12-12 16:57:07 -08002418 if (prev_class) {
Ganesh Mahendran64d90462016-07-28 15:47:51 -07002419 if (can_merge(prev_class, pages_per_zspage, objs_per_zspage)) {
Joonsoo Kim9eec4cd2014-12-12 16:56:44 -08002420 pool->size_class[i] = prev_class;
2421 continue;
2422 }
2423 }
2424
2425 class = kzalloc(sizeof(struct size_class), GFP_KERNEL);
2426 if (!class)
2427 goto err;
2428
Nitin Gupta61989a82012-01-09 16:51:56 -06002429 class->size = size;
2430 class->index = i;
Joonsoo Kim9eec4cd2014-12-12 16:56:44 -08002431 class->pages_per_zspage = pages_per_zspage;
Ganesh Mahendran64d90462016-07-28 15:47:51 -07002432 class->objs_per_zspage = objs_per_zspage;
Nitin Gupta61989a82012-01-09 16:51:56 -06002433 spin_lock_init(&class->lock);
Joonsoo Kim9eec4cd2014-12-12 16:56:44 -08002434 pool->size_class[i] = class;
Minchan Kim48b48002016-07-26 15:23:31 -07002435 for (fullness = ZS_EMPTY; fullness < NR_ZS_FULLNESS;
2436 fullness++)
Minchan Kim37836892016-07-26 15:23:23 -07002437 INIT_LIST_HEAD(&class->fullness_list[fullness]);
Ganesh Mahendrandf8b5bb2014-12-12 16:57:07 -08002438
2439 prev_class = class;
Nitin Gupta61989a82012-01-09 16:51:56 -06002440 }
2441
Dan Streetmand34f6152016-05-20 16:59:56 -07002442 /* debug only, don't abort if it fails */
2443 zs_pool_stat_create(pool, name);
Ganesh Mahendran0f050d92015-02-12 15:00:54 -08002444
Minchan Kim48b48002016-07-26 15:23:31 -07002445 if (zs_register_migration(pool))
2446 goto err;
2447
Sergey Senozhatskyab9d3062015-09-08 15:04:41 -07002448 /*
Aliaksei Karaliou93144ca2018-01-31 16:18:40 -08002449 * Not critical since shrinker is only used to trigger internal
2450 * defragmentation of the pool which is pretty optional thing. If
2451 * registration fails we still can use the pool normally and user can
2452 * trigger compaction manually. Thus, ignore return code.
Sergey Senozhatskyab9d3062015-09-08 15:04:41 -07002453 */
Aliaksei Karaliou93144ca2018-01-31 16:18:40 -08002454 zs_register_shrinker(pool);
2455
Nitin Gupta61989a82012-01-09 16:51:56 -06002456 return pool;
Joonsoo Kim9eec4cd2014-12-12 16:56:44 -08002457
2458err:
2459 zs_destroy_pool(pool);
2460 return NULL;
Nitin Gupta61989a82012-01-09 16:51:56 -06002461}
2462EXPORT_SYMBOL_GPL(zs_create_pool);
2463
2464void zs_destroy_pool(struct zs_pool *pool)
2465{
2466 int i;
2467
Sergey Senozhatskyab9d3062015-09-08 15:04:41 -07002468 zs_unregister_shrinker(pool);
Minchan Kim48b48002016-07-26 15:23:31 -07002469 zs_unregister_migration(pool);
Ganesh Mahendran0f050d92015-02-12 15:00:54 -08002470 zs_pool_stat_destroy(pool);
2471
Jerome Marchandcf8e0fed2017-07-10 15:50:18 -07002472 for (i = 0; i < ZS_SIZE_CLASSES; i++) {
Nitin Gupta61989a82012-01-09 16:51:56 -06002473 int fg;
Joonsoo Kim9eec4cd2014-12-12 16:56:44 -08002474 struct size_class *class = pool->size_class[i];
2475
2476 if (!class)
2477 continue;
2478
2479 if (class->index != i)
2480 continue;
Nitin Gupta61989a82012-01-09 16:51:56 -06002481
Minchan Kim48b48002016-07-26 15:23:31 -07002482 for (fg = ZS_EMPTY; fg < NR_ZS_FULLNESS; fg++) {
Minchan Kim37836892016-07-26 15:23:23 -07002483 if (!list_empty(&class->fullness_list[fg])) {
Marlies Ruck93ad5ab2013-05-15 16:56:49 -04002484 pr_info("Freeing non-empty class with size %db, fullness group %d\n",
Nitin Gupta61989a82012-01-09 16:51:56 -06002485 class->size, fg);
2486 }
2487 }
Joonsoo Kim9eec4cd2014-12-12 16:56:44 -08002488 kfree(class);
Nitin Gupta61989a82012-01-09 16:51:56 -06002489 }
Mahendran Ganesh40f9fb82014-12-12 16:57:01 -08002490
Minchan Kim37836892016-07-26 15:23:23 -07002491 destroy_cache(pool);
Ganesh Mahendran0f050d92015-02-12 15:00:54 -08002492 kfree(pool->name);
Nitin Gupta61989a82012-01-09 16:51:56 -06002493 kfree(pool);
2494}
2495EXPORT_SYMBOL_GPL(zs_destroy_pool);
2496
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08002497static int __init zs_init(void)
Nitin Gupta61989a82012-01-09 16:51:56 -06002498{
Minchan Kim48b48002016-07-26 15:23:31 -07002499 int ret;
2500
2501 ret = zsmalloc_mount();
2502 if (ret)
2503 goto out;
2504
Sebastian Andrzej Siewior215c89d2016-11-27 00:13:38 +01002505 ret = cpuhp_setup_state(CPUHP_MM_ZS_PREPARE, "mm/zsmalloc:prepare",
2506 zs_cpu_prepare, zs_cpu_dead);
Ganesh Mahendran0f050d92015-02-12 15:00:54 -08002507 if (ret)
Sebastian Andrzej Siewior215c89d2016-11-27 00:13:38 +01002508 goto hp_setup_fail;
Nitin Gupta61989a82012-01-09 16:51:56 -06002509
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08002510#ifdef CONFIG_ZPOOL
2511 zpool_register_driver(&zs_zpool_driver);
2512#endif
Ganesh Mahendran0f050d92015-02-12 15:00:54 -08002513
Dan Streetman4abaac92016-05-26 15:16:27 -07002514 zs_stat_init();
2515
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08002516 return 0;
Ganesh Mahendran0f050d92015-02-12 15:00:54 -08002517
Sebastian Andrzej Siewior215c89d2016-11-27 00:13:38 +01002518hp_setup_fail:
Minchan Kim48b48002016-07-26 15:23:31 -07002519 zsmalloc_unmount();
2520out:
Ganesh Mahendran0f050d92015-02-12 15:00:54 -08002521 return ret;
Nitin Gupta61989a82012-01-09 16:51:56 -06002522}
Nitin Gupta61989a82012-01-09 16:51:56 -06002523
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08002524static void __exit zs_exit(void)
Nitin Gupta61989a82012-01-09 16:51:56 -06002525{
Ganesh Mahendran66cdef62014-12-18 16:17:40 -08002526#ifdef CONFIG_ZPOOL
2527 zpool_unregister_driver(&zs_zpool_driver);
2528#endif
Minchan Kim48b48002016-07-26 15:23:31 -07002529 zsmalloc_unmount();
Sebastian Andrzej Siewior215c89d2016-11-27 00:13:38 +01002530 cpuhp_remove_state(CPUHP_MM_ZS_PREPARE);
Ganesh Mahendran0f050d92015-02-12 15:00:54 -08002531
2532 zs_stat_exit();
Nitin Gupta61989a82012-01-09 16:51:56 -06002533}
Ben Hutchings069f1012012-06-20 02:31:11 +01002534
2535module_init(zs_init);
2536module_exit(zs_exit);
2537
2538MODULE_LICENSE("Dual BSD/GPL");
2539MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>");