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authorLinus Torvalds <torvalds@linux-foundation.org>2013-11-22 08:10:34 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-11-22 08:10:34 -0800
commit24f971abbda045c24d5d6f2438a7785567d2fde9 (patch)
treea4df2b80eafa1199625b53464bcf34e786a03a28 /mm/slab.c
parent3bab0bf045e1cc4880e2cfc9351e52cf7ec8e35e (diff)
parent721ae22ae1a51c25871b7a0b543877aa94ff2a20 (diff)
Merge branch 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux
Pull SLAB changes from Pekka Enberg: "The patches from Joonsoo Kim switch mm/slab.c to use 'struct page' for slab internals similar to mm/slub.c. This reduces memory usage and improves performance: https://lkml.org/lkml/2013/10/16/155 Rest of the changes are bug fixes from various people" * 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux: (21 commits) mm, slub: fix the typo in mm/slub.c mm, slub: fix the typo in include/linux/slub_def.h slub: Handle NULL parameter in kmem_cache_flags slab: replace non-existing 'struct freelist *' with 'void *' slab: fix to calm down kmemleak warning slub: proper kmemleak tracking if CONFIG_SLUB_DEBUG disabled slab: rename slab_bufctl to slab_freelist slab: remove useless statement for checking pfmemalloc slab: use struct page for slab management slab: replace free and inuse in struct slab with newly introduced active slab: remove SLAB_LIMIT slab: remove kmem_bufctl_t slab: change the management method of free objects of the slab slab: use __GFP_COMP flag for allocating slab pages slab: use well-defined macro, virt_to_slab() slab: overloading the RCU head over the LRU for RCU free slab: remove cachep in struct slab_rcu slab: remove nodeid in struct slab slab: remove colouroff in struct slab slab: change return type of kmem_getpages() to struct page ...
Diffstat (limited to 'mm/slab.c')
-rw-r--r--mm/slab.c571
1 files changed, 217 insertions, 354 deletions
diff --git a/mm/slab.c b/mm/slab.c
index 0c8967bb2018..eb043bf05f4c 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -164,72 +164,6 @@
static bool pfmemalloc_active __read_mostly;
/*
- * kmem_bufctl_t:
- *
- * Bufctl's are used for linking objs within a slab
- * linked offsets.
- *
- * This implementation relies on "struct page" for locating the cache &
- * slab an object belongs to.
- * This allows the bufctl structure to be small (one int), but limits
- * the number of objects a slab (not a cache) can contain when off-slab
- * bufctls are used. The limit is the size of the largest general cache
- * that does not use off-slab slabs.
- * For 32bit archs with 4 kB pages, is this 56.
- * This is not serious, as it is only for large objects, when it is unwise
- * to have too many per slab.
- * Note: This limit can be raised by introducing a general cache whose size
- * is less than 512 (PAGE_SIZE<<3), but greater than 256.
- */
-
-typedef unsigned int kmem_bufctl_t;
-#define BUFCTL_END (((kmem_bufctl_t)(~0U))-0)
-#define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1)
-#define BUFCTL_ACTIVE (((kmem_bufctl_t)(~0U))-2)
-#define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-3)
-
-/*
- * struct slab_rcu
- *
- * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to
- * arrange for kmem_freepages to be called via RCU. This is useful if
- * we need to approach a kernel structure obliquely, from its address
- * obtained without the usual locking. We can lock the structure to
- * stabilize it and check it's still at the given address, only if we
- * can be sure that the memory has not been meanwhile reused for some
- * other kind of object (which our subsystem's lock might corrupt).
- *
- * rcu_read_lock before reading the address, then rcu_read_unlock after
- * taking the spinlock within the structure expected at that address.
- */
-struct slab_rcu {
- struct rcu_head head;
- struct kmem_cache *cachep;
- void *addr;
-};
-
-/*
- * struct slab
- *
- * Manages the objs in a slab. Placed either at the beginning of mem allocated
- * for a slab, or allocated from an general cache.
- * Slabs are chained into three list: fully used, partial, fully free slabs.
- */
-struct slab {
- union {
- struct {
- struct list_head list;
- unsigned long colouroff;
- void *s_mem; /* including colour offset */
- unsigned int inuse; /* num of objs active in slab */
- kmem_bufctl_t free;
- unsigned short nodeid;
- };
- struct slab_rcu __slab_cover_slab_rcu;
- };
-};
-
-/*
* struct array_cache
*
* Purpose:
@@ -456,18 +390,10 @@ static inline struct kmem_cache *virt_to_cache(const void *obj)
return page->slab_cache;
}
-static inline struct slab *virt_to_slab(const void *obj)
-{
- struct page *page = virt_to_head_page(obj);
-
- VM_BUG_ON(!PageSlab(page));
- return page->slab_page;
-}
-
-static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab,
+static inline void *index_to_obj(struct kmem_cache *cache, struct page *page,
unsigned int idx)
{
- return slab->s_mem + cache->size * idx;
+ return page->s_mem + cache->size * idx;
}
/*
@@ -477,9 +403,9 @@ static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab,
* reciprocal_divide(offset, cache->reciprocal_buffer_size)
*/
static inline unsigned int obj_to_index(const struct kmem_cache *cache,
- const struct slab *slab, void *obj)
+ const struct page *page, void *obj)
{
- u32 offset = (obj - slab->s_mem);
+ u32 offset = (obj - page->s_mem);
return reciprocal_divide(offset, cache->reciprocal_buffer_size);
}
@@ -641,7 +567,7 @@ static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
static size_t slab_mgmt_size(size_t nr_objs, size_t align)
{
- return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align);
+ return ALIGN(nr_objs * sizeof(unsigned int), align);
}
/*
@@ -660,8 +586,7 @@ static void cache_estimate(unsigned long gfporder, size_t buffer_size,
* on it. For the latter case, the memory allocated for a
* slab is used for:
*
- * - The struct slab
- * - One kmem_bufctl_t for each object
+ * - One unsigned int for each object
* - Padding to respect alignment of @align
* - @buffer_size bytes for each object
*
@@ -674,8 +599,6 @@ static void cache_estimate(unsigned long gfporder, size_t buffer_size,
mgmt_size = 0;
nr_objs = slab_size / buffer_size;
- if (nr_objs > SLAB_LIMIT)
- nr_objs = SLAB_LIMIT;
} else {
/*
* Ignore padding for the initial guess. The padding
@@ -685,8 +608,7 @@ static void cache_estimate(unsigned long gfporder, size_t buffer_size,
* into the memory allocation when taking the padding
* into account.
*/
- nr_objs = (slab_size - sizeof(struct slab)) /
- (buffer_size + sizeof(kmem_bufctl_t));
+ nr_objs = (slab_size) / (buffer_size + sizeof(unsigned int));
/*
* This calculated number will be either the right
@@ -696,9 +618,6 @@ static void cache_estimate(unsigned long gfporder, size_t buffer_size,
> slab_size)
nr_objs--;
- if (nr_objs > SLAB_LIMIT)
- nr_objs = SLAB_LIMIT;
-
mgmt_size = slab_mgmt_size(nr_objs, align);
}
*num = nr_objs;
@@ -829,10 +748,8 @@ static struct array_cache *alloc_arraycache(int node, int entries,
return nc;
}
-static inline bool is_slab_pfmemalloc(struct slab *slabp)
+static inline bool is_slab_pfmemalloc(struct page *page)
{
- struct page *page = virt_to_page(slabp->s_mem);
-
return PageSlabPfmemalloc(page);
}
@@ -841,23 +758,23 @@ static void recheck_pfmemalloc_active(struct kmem_cache *cachep,
struct array_cache *ac)
{
struct kmem_cache_node *n = cachep->node[numa_mem_id()];
- struct slab *slabp;
+ struct page *page;
unsigned long flags;
if (!pfmemalloc_active)
return;
spin_lock_irqsave(&n->list_lock, flags);
- list_for_each_entry(slabp, &n->slabs_full, list)
- if (is_slab_pfmemalloc(slabp))
+ list_for_each_entry(page, &n->slabs_full, lru)
+ if (is_slab_pfmemalloc(page))
goto out;
- list_for_each_entry(slabp, &n->slabs_partial, list)
- if (is_slab_pfmemalloc(slabp))
+ list_for_each_entry(page, &n->slabs_partial, lru)
+ if (is_slab_pfmemalloc(page))
goto out;
- list_for_each_entry(slabp, &n->slabs_free, list)
- if (is_slab_pfmemalloc(slabp))
+ list_for_each_entry(page, &n->slabs_free, lru)
+ if (is_slab_pfmemalloc(page))
goto out;
pfmemalloc_active = false;
@@ -897,8 +814,8 @@ static void *__ac_get_obj(struct kmem_cache *cachep, struct array_cache *ac,
*/
n = cachep->node[numa_mem_id()];
if (!list_empty(&n->slabs_free) && force_refill) {
- struct slab *slabp = virt_to_slab(objp);
- ClearPageSlabPfmemalloc(virt_to_head_page(slabp->s_mem));
+ struct page *page = virt_to_head_page(objp);
+ ClearPageSlabPfmemalloc(page);
clear_obj_pfmemalloc(&objp);
recheck_pfmemalloc_active(cachep, ac);
return objp;
@@ -1099,8 +1016,7 @@ static void drain_alien_cache(struct kmem_cache *cachep,
static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
{
- struct slab *slabp = virt_to_slab(objp);
- int nodeid = slabp->nodeid;
+ int nodeid = page_to_nid(virt_to_page(objp));
struct kmem_cache_node *n;
struct array_cache *alien = NULL;
int node;
@@ -1111,7 +1027,7 @@ static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
* Make sure we are not freeing a object from another node to the array
* cache on this cpu.
*/
- if (likely(slabp->nodeid == node))
+ if (likely(nodeid == node))
return 0;
n = cachep->node[node];
@@ -1512,6 +1428,8 @@ void __init kmem_cache_init(void)
{
int i;
+ BUILD_BUG_ON(sizeof(((struct page *)NULL)->lru) <
+ sizeof(struct rcu_head));
kmem_cache = &kmem_cache_boot;
setup_node_pointer(kmem_cache);
@@ -1687,7 +1605,7 @@ static noinline void
slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid)
{
struct kmem_cache_node *n;
- struct slab *slabp;
+ struct page *page;
unsigned long flags;
int node;
@@ -1706,15 +1624,15 @@ slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid)
continue;
spin_lock_irqsave(&n->list_lock, flags);
- list_for_each_entry(slabp, &n->slabs_full, list) {
+ list_for_each_entry(page, &n->slabs_full, lru) {
active_objs += cachep->num;
active_slabs++;
}
- list_for_each_entry(slabp, &n->slabs_partial, list) {
- active_objs += slabp->inuse;
+ list_for_each_entry(page, &n->slabs_partial, lru) {
+ active_objs += page->active;
active_slabs++;
}
- list_for_each_entry(slabp, &n->slabs_free, list)
+ list_for_each_entry(page, &n->slabs_free, lru)
num_slabs++;
free_objects += n->free_objects;
@@ -1736,19 +1654,11 @@ slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid)
* did not request dmaable memory, we might get it, but that
* would be relatively rare and ignorable.
*/
-static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
+static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
+ int nodeid)
{
struct page *page;
int nr_pages;
- int i;
-
-#ifndef CONFIG_MMU
- /*
- * Nommu uses slab's for process anonymous memory allocations, and thus
- * requires __GFP_COMP to properly refcount higher order allocations
- */
- flags |= __GFP_COMP;
-#endif
flags |= cachep->allocflags;
if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
@@ -1772,12 +1682,9 @@ static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
else
add_zone_page_state(page_zone(page),
NR_SLAB_UNRECLAIMABLE, nr_pages);
- for (i = 0; i < nr_pages; i++) {
- __SetPageSlab(page + i);
-
- if (page->pfmemalloc)
- SetPageSlabPfmemalloc(page + i);
- }
+ __SetPageSlab(page);
+ if (page->pfmemalloc)
+ SetPageSlabPfmemalloc(page);
memcg_bind_pages(cachep, cachep->gfporder);
if (kmemcheck_enabled && !(cachep->flags & SLAB_NOTRACK)) {
@@ -1789,17 +1696,15 @@ static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
kmemcheck_mark_unallocated_pages(page, nr_pages);
}
- return page_address(page);
+ return page;
}
/*
* Interface to system's page release.
*/
-static void kmem_freepages(struct kmem_cache *cachep, void *addr)
+static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
{
- unsigned long i = (1 << cachep->gfporder);
- struct page *page = virt_to_page(addr);
- const unsigned long nr_freed = i;
+ const unsigned long nr_freed = (1 << cachep->gfporder);
kmemcheck_free_shadow(page, cachep->gfporder);
@@ -1809,27 +1714,28 @@ static void kmem_freepages(struct kmem_cache *cachep, void *addr)
else
sub_zone_page_state(page_zone(page),
NR_SLAB_UNRECLAIMABLE, nr_freed);
- while (i--) {
- BUG_ON(!PageSlab(page));
- __ClearPageSlabPfmemalloc(page);
- __ClearPageSlab(page);
- page++;
- }
+
+ BUG_ON(!PageSlab(page));
+ __ClearPageSlabPfmemalloc(page);
+ __ClearPageSlab(page);
+ page_mapcount_reset(page);
+ page->mapping = NULL;
memcg_release_pages(cachep, cachep->gfporder);
if (current->reclaim_state)
current->reclaim_state->reclaimed_slab += nr_freed;
- free_memcg_kmem_pages((unsigned long)addr, cachep->gfporder);
+ __free_memcg_kmem_pages(page, cachep->gfporder);
}
static void kmem_rcu_free(struct rcu_head *head)
{
- struct slab_rcu *slab_rcu = (struct slab_rcu *)head;
- struct kmem_cache *cachep = slab_rcu->cachep;
+ struct kmem_cache *cachep;
+ struct page *page;
- kmem_freepages(cachep, slab_rcu->addr);
- if (OFF_SLAB(cachep))
- kmem_cache_free(cachep->slabp_cache, slab_rcu);
+ page = container_of(head, struct page, rcu_head);
+ cachep = page->slab_cache;
+
+ kmem_freepages(cachep, page);
}
#if DEBUG
@@ -1978,19 +1884,19 @@ static void check_poison_obj(struct kmem_cache *cachep, void *objp)
/* Print some data about the neighboring objects, if they
* exist:
*/
- struct slab *slabp = virt_to_slab(objp);
+ struct page *page = virt_to_head_page(objp);
unsigned int objnr;
- objnr = obj_to_index(cachep, slabp, objp);
+ objnr = obj_to_index(cachep, page, objp);
if (objnr) {
- objp = index_to_obj(cachep, slabp, objnr - 1);
+ objp = index_to_obj(cachep, page, objnr - 1);
realobj = (char *)objp + obj_offset(cachep);
printk(KERN_ERR "Prev obj: start=%p, len=%d\n",
realobj, size);
print_objinfo(cachep, objp, 2);
}
if (objnr + 1 < cachep->num) {
- objp = index_to_obj(cachep, slabp, objnr + 1);
+ objp = index_to_obj(cachep, page, objnr + 1);
realobj = (char *)objp + obj_offset(cachep);
printk(KERN_ERR "Next obj: start=%p, len=%d\n",
realobj, size);
@@ -2001,11 +1907,12 @@ static void check_poison_obj(struct kmem_cache *cachep, void *objp)
#endif
#if DEBUG
-static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp)
+static void slab_destroy_debugcheck(struct kmem_cache *cachep,
+ struct page *page)
{
int i;
for (i = 0; i < cachep->num; i++) {
- void *objp = index_to_obj(cachep, slabp, i);
+ void *objp = index_to_obj(cachep, page, i);
if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
@@ -2030,7 +1937,8 @@ static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slab
}
}
#else
-static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp)
+static void slab_destroy_debugcheck(struct kmem_cache *cachep,
+ struct page *page)
{
}
#endif
@@ -2044,23 +1952,34 @@ static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slab
* Before calling the slab must have been unlinked from the cache. The
* cache-lock is not held/needed.
*/
-static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
+static void slab_destroy(struct kmem_cache *cachep, struct page *page)
{
- void *addr = slabp->s_mem - slabp->colouroff;
+ void *freelist;
- slab_destroy_debugcheck(cachep, slabp);
+ freelist = page->freelist;
+ slab_destroy_debugcheck(cachep, page);
if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
- struct slab_rcu *slab_rcu;
+ struct rcu_head *head;
+
+ /*
+ * RCU free overloads the RCU head over the LRU.
+ * slab_page has been overloeaded over the LRU,
+ * however it is not used from now on so that
+ * we can use it safely.
+ */
+ head = (void *)&page->rcu_head;
+ call_rcu(head, kmem_rcu_free);
- slab_rcu = (struct slab_rcu *)slabp;
- slab_rcu->cachep = cachep;
- slab_rcu->addr = addr;
- call_rcu(&slab_rcu->head, kmem_rcu_free);
} else {
- kmem_freepages(cachep, addr);
- if (OFF_SLAB(cachep))
- kmem_cache_free(cachep->slabp_cache, slabp);
+ kmem_freepages(cachep, page);
}
+
+ /*
+ * From now on, we don't use freelist
+ * although actual page can be freed in rcu context
+ */
+ if (OFF_SLAB(cachep))
+ kmem_cache_free(cachep->freelist_cache, freelist);
}
/**
@@ -2097,8 +2016,8 @@ static size_t calculate_slab_order(struct kmem_cache *cachep,
* use off-slab slabs. Needed to avoid a possible
* looping condition in cache_grow().
*/
- offslab_limit = size - sizeof(struct slab);
- offslab_limit /= sizeof(kmem_bufctl_t);
+ offslab_limit = size;
+ offslab_limit /= sizeof(unsigned int);
if (num > offslab_limit)
break;
@@ -2220,7 +2139,7 @@ static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp)
int
__kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
{
- size_t left_over, slab_size, ralign;
+ size_t left_over, freelist_size, ralign;
gfp_t gfp;
int err;
size_t size = cachep->size;
@@ -2339,22 +2258,21 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
if (!cachep->num)
return -E2BIG;
- slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t)
- + sizeof(struct slab), cachep->align);
+ freelist_size =
+ ALIGN(cachep->num * sizeof(unsigned int), cachep->align);
/*
* If the slab has been placed off-slab, and we have enough space then
* move it on-slab. This is at the expense of any extra colouring.
*/
- if (flags & CFLGS_OFF_SLAB && left_over >= slab_size) {
+ if (flags & CFLGS_OFF_SLAB && left_over >= freelist_size) {
flags &= ~CFLGS_OFF_SLAB;
- left_over -= slab_size;
+ left_over -= freelist_size;
}
if (flags & CFLGS_OFF_SLAB) {
/* really off slab. No need for manual alignment */
- slab_size =
- cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab);
+ freelist_size = cachep->num * sizeof(unsigned int);
#ifdef CONFIG_PAGE_POISONING
/* If we're going to use the generic kernel_map_pages()
@@ -2371,16 +2289,16 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
if (cachep->colour_off < cachep->align)
cachep->colour_off = cachep->align;
cachep->colour = left_over / cachep->colour_off;
- cachep->slab_size = slab_size;
+ cachep->freelist_size = freelist_size;
cachep->flags = flags;
- cachep->allocflags = 0;
+ cachep->allocflags = __GFP_COMP;
if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA))
cachep->allocflags |= GFP_DMA;
cachep->size = size;
cachep->reciprocal_buffer_size = reciprocal_value(size);
if (flags & CFLGS_OFF_SLAB) {
- cachep->slabp_cache = kmalloc_slab(slab_size, 0u);
+ cachep->freelist_cache = kmalloc_slab(freelist_size, 0u);
/*
* This is a possibility for one of the malloc_sizes caches.
* But since we go off slab only for object size greater than
@@ -2388,7 +2306,7 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
* this should not happen at all.
* But leave a BUG_ON for some lucky dude.
*/
- BUG_ON(ZERO_OR_NULL_PTR(cachep->slabp_cache));
+ BUG_ON(ZERO_OR_NULL_PTR(cachep->freelist_cache));
}
err = setup_cpu_cache(cachep, gfp);
@@ -2494,7 +2412,7 @@ static int drain_freelist(struct kmem_cache *cache,
{
struct list_head *p;
int nr_freed;
- struct slab *slabp;
+ struct page *page;
nr_freed = 0;
while (nr_freed < tofree && !list_empty(&n->slabs_free)) {
@@ -2506,18 +2424,18 @@ static int drain_freelist(struct kmem_cache *cache,
goto out;
}
- slabp = list_entry(p, struct slab, list);
+ page = list_entry(p, struct page, lru);
#if DEBUG
- BUG_ON(slabp->inuse);
+ BUG_ON(page->active);
#endif
- list_del(&slabp->list);
+ list_del(&page->lru);
/*
* Safe to drop the lock. The slab is no longer linked
* to the cache.
*/
n->free_objects -= cache->num;
spin_unlock_irq(&n->list_lock);
- slab_destroy(cache, slabp);
+ slab_destroy(cache, page);
nr_freed++;
}
out:
@@ -2600,52 +2518,42 @@ int __kmem_cache_shutdown(struct kmem_cache *cachep)
* descriptors in kmem_cache_create, we search through the malloc_sizes array.
* If we are creating a malloc_sizes cache here it would not be visible to
* kmem_find_general_cachep till the initialization is complete.
- * Hence we cannot have slabp_cache same as the original cache.
+ * Hence we cannot have freelist_cache same as the original cache.
*/
-static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp,
- int colour_off, gfp_t local_flags,
- int nodeid)
+static void *alloc_slabmgmt(struct kmem_cache *cachep,
+ struct page *page, int colour_off,
+ gfp_t local_flags, int nodeid)
{
- struct slab *slabp;
+ void *freelist;
+ void *addr = page_address(page);
if (OFF_SLAB(cachep)) {
/* Slab management obj is off-slab. */
- slabp = kmem_cache_alloc_node(cachep->slabp_cache,
+ freelist = kmem_cache_alloc_node(cachep->freelist_cache,
local_flags, nodeid);
- /*
- * If the first object in the slab is leaked (it's allocated
- * but no one has a reference to it), we want to make sure
- * kmemleak does not treat the ->s_mem pointer as a reference
- * to the object. Otherwise we will not report the leak.
- */
- kmemleak_scan_area(&slabp->list, sizeof(struct list_head),
- local_flags);
- if (!slabp)
+ if (!freelist)
return NULL;
} else {
- slabp = objp + colour_off;
- colour_off += cachep->slab_size;
+ freelist = addr + colour_off;
+ colour_off += cachep->freelist_size;
}
- slabp->inuse = 0;
- slabp->colouroff = colour_off;
- slabp->s_mem = objp + colour_off;
- slabp->nodeid = nodeid;
- slabp->free = 0;
- return slabp;
+ page->active = 0;
+ page->s_mem = addr + colour_off;
+ return freelist;
}
-static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp)
+static inline unsigned int *slab_freelist(struct page *page)
{
- return (kmem_bufctl_t *) (slabp + 1);
+ return (unsigned int *)(page->freelist);
}
static void cache_init_objs(struct kmem_cache *cachep,
- struct slab *slabp)
+ struct page *page)
{
int i;
for (i = 0; i < cachep->num; i++) {
- void *objp = index_to_obj(cachep, slabp, i);
+ void *objp = index_to_obj(cachep, page, i);
#if DEBUG
/* need to poison the objs? */
if (cachep->flags & SLAB_POISON)
@@ -2681,9 +2589,8 @@ static void cache_init_objs(struct kmem_cache *cachep,
if (cachep->ctor)
cachep->ctor(objp);
#endif
- slab_bufctl(slabp)[i] = i + 1;
+ slab_freelist(page)[i] = i;
}
- slab_bufctl(slabp)[i - 1] = BUFCTL_END;
}
static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
@@ -2696,41 +2603,41 @@ static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
}
}
-static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp,
+static void *slab_get_obj(struct kmem_cache *cachep, struct page *page,
int nodeid)
{
- void *objp = index_to_obj(cachep, slabp, slabp->free);
- kmem_bufctl_t next;
+ void *objp;
- slabp->inuse++;
- next = slab_bufctl(slabp)[slabp->free];
+ objp = index_to_obj(cachep, page, slab_freelist(page)[page->active]);
+ page->active++;
#if DEBUG
- slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE;
- WARN_ON(slabp->nodeid != nodeid);
+ WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid);
#endif
- slabp->free = next;
return objp;
}
-static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
+static void slab_put_obj(struct kmem_cache *cachep, struct page *page,
void *objp, int nodeid)
{
- unsigned int objnr = obj_to_index(cachep, slabp, objp);
-
+ unsigned int objnr = obj_to_index(cachep, page, objp);
#if DEBUG
+ unsigned int i;
+
/* Verify that the slab belongs to the intended node */
- WARN_ON(slabp->nodeid != nodeid);
+ WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid);
- if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) {
- printk(KERN_ERR "slab: double free detected in cache "
- "'%s', objp %p\n", cachep->name, objp);
- BUG();
+ /* Verify double free bug */
+ for (i = page->active; i < cachep->num; i++) {
+ if (slab_freelist(page)[i] == objnr) {
+ printk(KERN_ERR "slab: double free detected in cache "
+ "'%s', objp %p\n", cachep->name, objp);
+ BUG();
+ }
}
#endif
- slab_bufctl(slabp)[objnr] = slabp->free;
- slabp->free = objnr;
- slabp->inuse--;
+ page->active--;
+ slab_freelist(page)[page->active] = objnr;
}
/*
@@ -2738,23 +2645,11 @@ static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
* for the slab allocator to be able to lookup the cache and slab of a
* virtual address for kfree, ksize, and slab debugging.
*/
-static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
- void *addr)
+static void slab_map_pages(struct kmem_cache *cache, struct page *page,
+ void *freelist)
{
- int nr_pages;
- struct page *page;
-
- page = virt_to_page(addr);
-
- nr_pages = 1;
- if (likely(!PageCompound(page)))
- nr_pages <<= cache->gfporder;
-
- do {
- page->slab_cache = cache;
- page->slab_page = slab;
- page++;
- } while (--nr_pages);
+ page->slab_cache = cache;
+ page->freelist = freelist;
}
/*
@@ -2762,9 +2657,9 @@ static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
* kmem_cache_alloc() when there are no active objs left in a cache.
*/
static int cache_grow(struct kmem_cache *cachep,
- gfp_t flags, int nodeid, void *objp)
+ gfp_t flags, int nodeid, struct page *page)
{
- struct slab *slabp;
+ void *freelist;
size_t offset;
gfp_t local_flags;
struct kmem_cache_node *n;
@@ -2805,20 +2700,20 @@ static int cache_grow(struct kmem_cache *cachep,
* Get mem for the objs. Attempt to allocate a physical page from
* 'nodeid'.
*/
- if (!objp)
- objp = kmem_getpages(cachep, local_flags, nodeid);
- if (!objp)
+ if (!page)
+ page = kmem_getpages(cachep, local_flags, nodeid);
+ if (!page)
goto failed;
/* Get slab management. */
- slabp = alloc_slabmgmt(cachep, objp, offset,
+ freelist = alloc_slabmgmt(cachep, page, offset,
local_flags & ~GFP_CONSTRAINT_MASK, nodeid);
- if (!slabp)
+ if (!freelist)
goto opps1;
- slab_map_pages(cachep, slabp, objp);
+ slab_map_pages(cachep, page, freelist);
- cache_init_objs(cachep, slabp);
+ cache_init_objs(cachep, page);
if (local_flags & __GFP_WAIT)
local_irq_disable();
@@ -2826,13 +2721,13 @@ static int cache_grow(struct kmem_cache *cachep,
spin_lock(&n->list_lock);
/* Make slab active. */
- list_add_tail(&slabp->list, &(n->slabs_free));
+ list_add_tail(&page->lru, &(n->slabs_free));
STATS_INC_GROWN(cachep);
n->free_objects += cachep->num;
spin_unlock(&n->list_lock);
return 1;
opps1:
- kmem_freepages(cachep, objp);
+ kmem_freepages(cachep, page);
failed:
if (local_flags & __GFP_WAIT)
local_irq_disable();
@@ -2880,9 +2775,8 @@ static inline void verify_redzone_free(struct kmem_cache *cache, void *obj)
static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
unsigned long caller)
{
- struct page *page;
unsigned int objnr;
- struct slab *slabp;
+ struct page *page;
BUG_ON(virt_to_cache(objp) != cachep);
@@ -2890,8 +2784,6 @@ static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
kfree_debugcheck(objp);
page = virt_to_head_page(objp);
- slabp = page->slab_page;
-
if (cachep->flags & SLAB_RED_ZONE) {
verify_redzone_free(cachep, objp);
*dbg_redzone1(cachep, objp) = RED_INACTIVE;
@@ -2900,14 +2792,11 @@ static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
if (cachep->flags & SLAB_STORE_USER)
*dbg_userword(cachep, objp) = (void *)caller;
- objnr = obj_to_index(cachep, slabp, objp);
+ objnr = obj_to_index(cachep, page, objp);
BUG_ON(objnr >= cachep->num);
- BUG_ON(objp != index_to_obj(cachep, slabp, objnr));
+ BUG_ON(objp != index_to_obj(cachep, page, objnr));
-#ifdef CONFIG_DEBUG_SLAB_LEAK
- slab_bufctl(slabp)[objnr] = BUFCTL_FREE;
-#endif
if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
if ((cachep->size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) {
@@ -2924,33 +2813,9 @@ static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
return objp;
}
-static void check_slabp(struct kmem_cache *cachep, struct slab *slabp)
-{
- kmem_bufctl_t i;
- int entries = 0;
-
- /* Check slab's freelist to see if this obj is there. */
- for (i = slabp->free; i != BUFCTL_END; i = slab_bufctl(slabp)[i]) {
- entries++;
- if (entries > cachep->num || i >= cachep->num)
- goto bad;
- }
- if (entries != cachep->num - slabp->inuse) {
-bad:
- printk(KERN_ERR "slab: Internal list corruption detected in "
- "cache '%s'(%d), slabp %p(%d). Tainted(%s). Hexdump:\n",
- cachep->name, cachep->num, slabp, slabp->inuse,
- print_tainted());
- print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1, slabp,
- sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t),
- 1);
- BUG();
- }
-}
#else
#define kfree_debugcheck(x) do { } while(0)
#define cache_free_debugcheck(x,objp,z) (objp)
-#define check_slabp(x,y) do { } while(0)
#endif
static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags,
@@ -2989,7 +2854,7 @@ retry:
while (batchcount > 0) {
struct list_head *entry;
- struct slab *slabp;
+ struct page *page;
/* Get slab alloc is to come from. */
entry = n->slabs_partial.next;
if (entry == &n->slabs_partial) {
@@ -2999,8 +2864,7 @@ retry:
goto must_grow;
}
- slabp = list_entry(entry, struct slab, list);
- check_slabp(cachep, slabp);
+ page = list_entry(entry, struct page, lru);
check_spinlock_acquired(cachep);
/*
@@ -3008,24 +2872,23 @@ retry:
* there must be at least one object available for
* allocation.
*/
- BUG_ON(slabp->inuse >= cachep->num);
+ BUG_ON(page->active >= cachep->num);
- while (slabp->inuse < cachep->num && batchcount--) {
+ while (page->active < cachep->num && batchcount--) {
STATS_INC_ALLOCED(cachep);
STATS_INC_ACTIVE(cachep);
STATS_SET_HIGH(cachep);
- ac_put_obj(cachep, ac, slab_get_obj(cachep, slabp,
+ ac_put_obj(cachep, ac, slab_get_obj(cachep, page,
node));
}
- check_slabp(cachep, slabp);
/* move slabp to correct slabp list: */
- list_del(&slabp->list);
- if (slabp->free == BUFCTL_END)
- list_add(&slabp->list, &n->slabs_full);
+ list_del(&page->lru);
+ if (page->active == cachep->num)
+ list_add(&page->list, &n->slabs_full);
else
- list_add(&slabp->list, &n->slabs_partial);
+ list_add(&page->list, &n->slabs_partial);
}
must_grow:
@@ -3097,16 +2960,6 @@ static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
*dbg_redzone1(cachep, objp) = RED_ACTIVE;
*dbg_redzone2(cachep, objp) = RED_ACTIVE;
}
-#ifdef CONFIG_DEBUG_SLAB_LEAK
- {
- struct slab *slabp;
- unsigned objnr;
-
- slabp = virt_to_head_page(objp)->slab_page;
- objnr = (unsigned)(objp - slabp->s_mem) / cachep->size;
- slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE;
- }
-#endif
objp += obj_offset(cachep);
if (cachep->ctor && cachep->flags & SLAB_POISON)
cachep->ctor(objp);
@@ -3248,18 +3101,20 @@ retry:
* We may trigger various forms of reclaim on the allowed
* set and go into memory reserves if necessary.
*/
+ struct page *page;
+
if (local_flags & __GFP_WAIT)
local_irq_enable();
kmem_flagcheck(cache, flags);
- obj = kmem_getpages(cache, local_flags, numa_mem_id());
+ page = kmem_getpages(cache, local_flags, numa_mem_id());
if (local_flags & __GFP_WAIT)
local_irq_disable();
- if (obj) {
+ if (page) {
/*
* Insert into the appropriate per node queues
*/
- nid = page_to_nid(virt_to_page(obj));
- if (cache_grow(cache, flags, nid, obj)) {
+ nid = page_to_nid(page);
+ if (cache_grow(cache, flags, nid, page)) {
obj = ____cache_alloc_node(cache,
flags | GFP_THISNODE, nid);
if (!obj)
@@ -3288,7 +3143,7 @@ static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
int nodeid)
{
struct list_head *entry;
- struct slab *slabp;
+ struct page *page;
struct kmem_cache_node *n;
void *obj;
int x;
@@ -3308,26 +3163,24 @@ retry:
goto must_grow;
}
- slabp = list_entry(entry, struct slab, list);
+ page = list_entry(entry, struct page, lru);
check_spinlock_acquired_node(cachep, nodeid);
- check_slabp(cachep, slabp);
STATS_INC_NODEALLOCS(cachep);
STATS_INC_ACTIVE(cachep);
STATS_SET_HIGH(cachep);
- BUG_ON(slabp->inuse == cachep->num);
+ BUG_ON(page->active == cachep->num);
- obj = slab_get_obj(cachep, slabp, nodeid);
- check_slabp(cachep, slabp);
+ obj = slab_get_obj(cachep, page, nodeid);
n->free_objects--;
/* move slabp to correct slabp list: */
- list_del(&slabp->list);
+ list_del(&page->lru);
- if (slabp->free == BUFCTL_END)
- list_add(&slabp->list, &n->slabs_full);
+ if (page->active == cachep->num)
+ list_add(&page->lru, &n->slabs_full);
else
- list_add(&slabp->list, &n->slabs_partial);
+ list_add(&page->lru, &n->slabs_partial);
spin_unlock(&n->list_lock);
goto done;
@@ -3477,23 +3330,21 @@ static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
for (i = 0; i < nr_objects; i++) {
void *objp;
- struct slab *slabp;
+ struct page *page;
clear_obj_pfmemalloc(&objpp[i]);
objp = objpp[i];
- slabp = virt_to_slab(objp);
+ page = virt_to_head_page(objp);
n = cachep->node[node];
- list_del(&slabp->list);
+ list_del(&page->lru);
check_spinlock_acquired_node(cachep, node);
- check_slabp(cachep, slabp);
- slab_put_obj(cachep, slabp, objp, node);
+ slab_put_obj(cachep, page, objp, node);
STATS_DEC_ACTIVE(cachep);
n->free_objects++;
- check_slabp(cachep, slabp);
/* fixup slab chains */
- if (slabp->inuse == 0) {
+ if (page->active == 0) {
if (n->free_objects > n->free_limit) {
n->free_objects -= cachep->num;
/* No need to drop any previously held
@@ -3502,16 +3353,16 @@ static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
* a different cache, refer to comments before
* alloc_slabmgmt.
*/
- slab_destroy(cachep, slabp);
+ slab_destroy(cachep, page);
} else {
- list_add(&slabp->list, &n->slabs_free);
+ list_add(&page->lru, &n->slabs_free);
}
} else {
/* Unconditionally move a slab to the end of the
* partial list on free - maximum time for the
* other objects to be freed, too.
*/
- list_add_tail(&slabp->list, &n->slabs_partial);
+ list_add_tail(&page->lru, &n->slabs_partial);
}
}
}
@@ -3551,10 +3402,10 @@ free_done:
p = n->slabs_free.next;
while (p != &(n->slabs_free)) {
- struct slab *slabp;
+ struct page *page;
- slabp = list_entry(p, struct slab, list);
- BUG_ON(slabp->inuse);
+ page = list_entry(p, struct page, lru);
+ BUG_ON(page->active);
i++;
p = p->next;
@@ -4158,7 +4009,7 @@ out:
#ifdef CONFIG_SLABINFO
void get_slabinfo(struct kmem_cache *cachep, struct slabinfo *sinfo)
{
- struct slab *slabp;
+ struct page *page;
unsigned long active_objs;
unsigned long num_objs;
unsigned long active_slabs = 0;
@@ -4178,23 +4029,23 @@ void get_slabinfo(struct kmem_cache *cachep, struct slabinfo *sinfo)
check_irq_on();
spin_lock_irq(&n->list_lock);
- list_for_each_entry(slabp, &n->slabs_full, list) {
- if (slabp->inuse != cachep->num && !error)
+ list_for_each_entry(page, &n->slabs_full, lru) {
+ if (page->active != cachep->num && !error)
error = "slabs_full accounting error";
active_objs += cachep->num;
active_slabs++;
}
- list_for_each_entry(slabp, &n->slabs_partial, list) {
- if (slabp->inuse == cachep->num && !error)
- error = "slabs_partial inuse accounting error";
- if (!slabp->inuse && !error)
- error = "slabs_partial/inuse accounting error";
- active_objs += slabp->inuse;
+ list_for_each_entry(page, &n->slabs_partial, lru) {
+ if (page->active == cachep->num && !error)
+ error = "slabs_partial accounting error";
+ if (!page->active && !error)
+ error = "slabs_partial accounting error";
+ active_objs += page->active;
active_slabs++;
}
- list_for_each_entry(slabp, &n->slabs_free, list) {
- if (slabp->inuse && !error)
- error = "slabs_free/inuse accounting error";
+ list_for_each_entry(page, &n->slabs_free, lru) {
+ if (page->active && !error)
+ error = "slabs_free accounting error";
num_slabs++;
}
free_objects += n->free_objects;
@@ -4346,15 +4197,27 @@ static inline int add_caller(unsigned long *n, unsigned long v)
return 1;
}
-static void handle_slab(unsigned long *n, struct kmem_cache *c, struct slab *s)
+static void handle_slab(unsigned long *n, struct kmem_cache *c,
+ struct page *page)
{
void *p;
- int i;
+ int i, j;
+
if (n[0] == n[1])
return;
- for (i = 0, p = s->s_mem; i < c->num; i++, p += c->size) {
- if (slab_bufctl(s)[i] != BUFCTL_ACTIVE)
+ for (i = 0, p = page->s_mem; i < c->num; i++, p += c->size) {
+ bool active = true;
+
+ for (j = page->active; j < c->num; j++) {
+ /* Skip freed item */
+ if (slab_freelist(page)[j] == i) {
+ active = false;
+ break;
+ }
+ }
+ if (!active)
continue;
+
if (!add_caller(n, (unsigned long)*dbg_userword(c, p)))
return;
}
@@ -4379,7 +4242,7 @@ static void show_symbol(struct seq_file *m, unsigned long address)
static int leaks_show(struct seq_file *m, void *p)
{
struct kmem_cache *cachep = list_entry(p, struct kmem_cache, list);
- struct slab *slabp;
+ struct page *page;
struct kmem_cache_node *n;
const char *name;
unsigned long *x = m->private;
@@ -4403,10 +4266,10 @@ static int leaks_show(struct seq_file *m, void *p)
check_irq_on();
spin_lock_irq(&n->list_lock);
- list_for_each_entry(slabp, &n->slabs_full, list)
- handle_slab(x, cachep, slabp);
- list_for_each_entry(slabp, &n->slabs_partial, list)
- handle_slab(x, cachep, slabp);
+ list_for_each_entry(page, &n->slabs_full, lru)
+ handle_slab(x, cachep, page);
+ list_for_each_entry(page, &n->slabs_partial, lru)
+ handle_slab(x, cachep, page);
spin_unlock_irq(&n->list_lock);
}
name = cachep->name;