#define CFLGS_OFF_SLAB (0x80000000UL)
#define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB)
-#define OFF_SLAB_MIN_SIZE (max_t(size_t, PAGE_SIZE >> 5, KMALLOC_MIN_SIZE + 1))
#define BATCHREFILL_LIMIT 16
/*
#endif
-#define OBJECT_FREE (0)
-#define OBJECT_ACTIVE (1)
-
#ifdef CONFIG_DEBUG_SLAB_LEAK
-static void set_obj_status(struct page *page, int idx, int val)
-{
- int freelist_size;
- char *status;
- struct kmem_cache *cachep = page->slab_cache;
-
- freelist_size = cachep->num * sizeof(freelist_idx_t);
- status = (char *)page->freelist + freelist_size;
- status[idx] = val;
-}
-
static inline bool is_store_user_clean(struct kmem_cache *cachep)
{
return atomic_read(&cachep->store_user_clean) == 1;
}
#else
-static inline void set_obj_status(struct page *page, int idx, int val) {}
static inline void set_store_user_dirty(struct kmem_cache *cachep) {}
#endif
return this_cpu_ptr(cachep->cpu_cache);
}
-static size_t calculate_freelist_size(int nr_objs, size_t align)
-{
- size_t freelist_size;
-
- freelist_size = nr_objs * sizeof(freelist_idx_t);
- if (IS_ENABLED(CONFIG_DEBUG_SLAB_LEAK))
- freelist_size += nr_objs * sizeof(char);
-
- if (align)
- freelist_size = ALIGN(freelist_size, align);
-
- return freelist_size;
-}
-
-static int calculate_nr_objs(size_t slab_size, size_t buffer_size,
- size_t idx_size, size_t align)
-{
- int nr_objs;
- size_t remained_size;
- size_t freelist_size;
- int extra_space = 0;
-
- if (IS_ENABLED(CONFIG_DEBUG_SLAB_LEAK))
- extra_space = sizeof(char);
- /*
- * Ignore padding for the initial guess. The padding
- * is at most @align-1 bytes, and @buffer_size is at
- * least @align. In the worst case, this result will
- * be one greater than the number of objects that fit
- * into the memory allocation when taking the padding
- * into account.
- */
- nr_objs = slab_size / (buffer_size + idx_size + extra_space);
-
- /*
- * This calculated number will be either the right
- * amount, or one greater than what we want.
- */
- remained_size = slab_size - nr_objs * buffer_size;
- freelist_size = calculate_freelist_size(nr_objs, align);
- if (remained_size < freelist_size)
- nr_objs--;
-
- return nr_objs;
-}
-
/*
* Calculate the number of objects and left-over bytes for a given buffer size.
*/
static void cache_estimate(unsigned long gfporder, size_t buffer_size,
- size_t align, int flags, size_t *left_over,
- unsigned int *num)
+ unsigned long flags, size_t *left_over, unsigned int *num)
{
- int nr_objs;
- size_t mgmt_size;
size_t slab_size = PAGE_SIZE << gfporder;
/*
* on it. For the latter case, the memory allocated for a
* slab is used for:
*
- * - One freelist_idx_t for each object
- * - Padding to respect alignment of @align
* - @buffer_size bytes for each object
+ * - One freelist_idx_t for each object
+ *
+ * We don't need to consider alignment of freelist because
+ * freelist will be at the end of slab page. The objects will be
+ * at the correct alignment.
*
* If the slab management structure is off the slab, then the
* alignment will already be calculated into the size. Because
* correct alignment when allocated.
*/
if (flags & CFLGS_OFF_SLAB) {
- mgmt_size = 0;
- nr_objs = slab_size / buffer_size;
-
+ *num = slab_size / buffer_size;
+ *left_over = slab_size % buffer_size;
} else {
- nr_objs = calculate_nr_objs(slab_size, buffer_size,
- sizeof(freelist_idx_t), align);
- mgmt_size = calculate_freelist_size(nr_objs, align);
+ *num = slab_size / (buffer_size + sizeof(freelist_idx_t));
+ *left_over = slab_size %
+ (buffer_size + sizeof(freelist_idx_t));
}
- *num = nr_objs;
- *left_over = slab_size - nr_objs*buffer_size - mgmt_size;
}
#if DEBUG
* calculate_slab_order - calculate size (page order) of slabs
* @cachep: pointer to the cache that is being created
* @size: size of objects to be created in this cache.
- * @align: required alignment for the objects.
* @flags: slab allocation flags
*
* Also calculates the number of objects per slab.
* towards high-order requests, this should be changed.
*/
static size_t calculate_slab_order(struct kmem_cache *cachep,
- size_t size, size_t align, unsigned long flags)
+ size_t size, unsigned long flags)
{
- unsigned long offslab_limit;
size_t left_over = 0;
int gfporder;
unsigned int num;
size_t remainder;
- cache_estimate(gfporder, size, align, flags, &remainder, &num);
+ cache_estimate(gfporder, size, flags, &remainder, &num);
if (!num)
continue;
break;
if (flags & CFLGS_OFF_SLAB) {
- size_t freelist_size_per_obj = sizeof(freelist_idx_t);
+ struct kmem_cache *freelist_cache;
+ size_t freelist_size;
+
+ freelist_size = num * sizeof(freelist_idx_t);
+ freelist_cache = kmalloc_slab(freelist_size, 0u);
+ if (!freelist_cache)
+ continue;
+
/*
- * Max number of objs-per-slab for caches which
- * use off-slab slabs. Needed to avoid a possible
- * looping condition in cache_grow().
+ * Needed to avoid possible looping condition
+ * in cache_grow()
*/
- if (IS_ENABLED(CONFIG_DEBUG_SLAB_LEAK))
- freelist_size_per_obj += sizeof(char);
- offslab_limit = size;
- offslab_limit /= freelist_size_per_obj;
+ if (OFF_SLAB(freelist_cache))
+ continue;
- if (num > offslab_limit)
- break;
+ /* check if off slab has enough benefit */
+ if (freelist_cache->size > cachep->size / 2)
+ continue;
}
/* Found something acceptable - save it away */
return cachep;
}
+static bool set_off_slab_cache(struct kmem_cache *cachep,
+ size_t size, unsigned long flags)
+{
+ size_t left;
+
+ cachep->num = 0;
+
+ /*
+ * Always use on-slab management when SLAB_NOLEAKTRACE
+ * to avoid recursive calls into kmemleak.
+ */
+ if (flags & SLAB_NOLEAKTRACE)
+ return false;
+
+ /*
+ * Size is large, assume best to place the slab management obj
+ * off-slab (should allow better packing of objs).
+ */
+ left = calculate_slab_order(cachep, size, flags | CFLGS_OFF_SLAB);
+ if (!cachep->num)
+ return false;
+
+ /*
+ * 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 (left >= cachep->num * sizeof(freelist_idx_t))
+ return false;
+
+ cachep->colour = left / cachep->colour_off;
+
+ return true;
+}
+
+static bool set_on_slab_cache(struct kmem_cache *cachep,
+ size_t size, unsigned long flags)
+{
+ size_t left;
+
+ cachep->num = 0;
+
+ left = calculate_slab_order(cachep, size, flags);
+ if (!cachep->num)
+ return false;
+
+ cachep->colour = left / cachep->colour_off;
+
+ return true;
+}
+
/**
* __kmem_cache_create - Create a cache.
* @cachep: cache management descriptor
int
__kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
{
- size_t left_over, freelist_size;
size_t ralign = BYTES_PER_WORD;
gfp_t gfp;
int err;
* 4) Store it.
*/
cachep->align = ralign;
+ cachep->colour_off = cache_line_size();
+ /* Offset must be a multiple of the alignment. */
+ if (cachep->colour_off < cachep->align)
+ cachep->colour_off = cachep->align;
if (slab_is_available())
gfp = GFP_KERNEL;
else
size += BYTES_PER_WORD;
}
- /*
- * To activate debug pagealloc, off-slab management is necessary
- * requirement. In early phase of initialization, small sized slab
- * doesn't get initialized so it would not be possible. So, we need
- * to check size >= 256. It guarantees that all necessary small
- * sized slab is initialized in current slab initialization sequence.
- */
- if (debug_pagealloc_enabled() && (flags & SLAB_POISON) &&
- !slab_early_init && size >= kmalloc_size(INDEX_NODE) &&
- size >= 256 && cachep->object_size > cache_line_size() &&
- ALIGN(size, cachep->align) < PAGE_SIZE) {
- cachep->obj_offset += PAGE_SIZE - ALIGN(size, cachep->align);
- size = PAGE_SIZE;
- }
#endif
- /*
- * Determine if the slab management is 'on' or 'off' slab.
- * (bootstrapping cannot cope with offslab caches so don't do
- * it too early on. Always use on-slab management when
- * SLAB_NOLEAKTRACE to avoid recursive calls into kmemleak)
- */
- if (size >= OFF_SLAB_MIN_SIZE && !slab_early_init &&
- !(flags & SLAB_NOLEAKTRACE))
- /*
- * Size is large, assume best to place the slab management obj
- * off-slab (should allow better packing of objs).
- */
- flags |= CFLGS_OFF_SLAB;
-
size = ALIGN(size, cachep->align);
/*
* We should restrict the number of objects in a slab to implement
if (FREELIST_BYTE_INDEX && size < SLAB_OBJ_MIN_SIZE)
size = ALIGN(SLAB_OBJ_MIN_SIZE, cachep->align);
- left_over = calculate_slab_order(cachep, size, cachep->align, flags);
-
- if (!cachep->num)
- return -E2BIG;
-
- freelist_size = calculate_freelist_size(cachep->num, cachep->align);
-
+#if DEBUG
/*
- * 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.
+ * To activate debug pagealloc, off-slab management is necessary
+ * requirement. In early phase of initialization, small sized slab
+ * doesn't get initialized so it would not be possible. So, we need
+ * to check size >= 256. It guarantees that all necessary small
+ * sized slab is initialized in current slab initialization sequence.
*/
- if (flags & CFLGS_OFF_SLAB && left_over >= freelist_size) {
- flags &= ~CFLGS_OFF_SLAB;
- left_over -= freelist_size;
+ if (debug_pagealloc_enabled() && (flags & SLAB_POISON) &&
+ size >= 256 && cachep->object_size > cache_line_size()) {
+ if (size < PAGE_SIZE || size % PAGE_SIZE == 0) {
+ size_t tmp_size = ALIGN(size, PAGE_SIZE);
+
+ if (set_off_slab_cache(cachep, tmp_size, flags)) {
+ flags |= CFLGS_OFF_SLAB;
+ cachep->obj_offset += tmp_size - size;
+ size = tmp_size;
+ goto done;
+ }
+ }
}
+#endif
- if (flags & CFLGS_OFF_SLAB) {
- /* really off slab. No need for manual alignment */
- freelist_size = calculate_freelist_size(cachep->num, 0);
+ if (set_off_slab_cache(cachep, size, flags)) {
+ flags |= CFLGS_OFF_SLAB;
+ goto done;
}
- cachep->colour_off = cache_line_size();
- /* Offset must be a multiple of the alignment. */
- if (cachep->colour_off < cachep->align)
- cachep->colour_off = cachep->align;
- cachep->colour = left_over / cachep->colour_off;
- cachep->freelist_size = freelist_size;
+ if (set_on_slab_cache(cachep, size, flags))
+ goto done;
+
+ return -E2BIG;
+
+done:
+ cachep->freelist_size = cachep->num * sizeof(freelist_idx_t);
cachep->flags = flags;
cachep->allocflags = __GFP_COMP;
if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA))
#endif
if (OFF_SLAB(cachep)) {
- cachep->freelist_cache = kmalloc_slab(freelist_size, 0u);
- /*
- * This is a possibility for one of the kmalloc_{dma,}_caches.
- * But since we go off slab only for object size greater than
- * OFF_SLAB_MIN_SIZE, and kmalloc_{dma,}_caches get created
- * in ascending order,this should not happen at all.
- * But leave a BUG_ON for some lucky dude.
- */
- BUG_ON(ZERO_OR_NULL_PTR(cachep->freelist_cache));
+ cachep->freelist_cache =
+ kmalloc_slab(cachep->freelist_size, 0u);
}
err = setup_cpu_cache(cachep, gfp);
void *freelist;
void *addr = page_address(page);
+ page->s_mem = addr + colour_off;
+ page->active = 0;
+
if (OFF_SLAB(cachep)) {
/* Slab management obj is off-slab. */
freelist = kmem_cache_alloc_node(cachep->freelist_cache,
if (!freelist)
return NULL;
} else {
- freelist = addr + colour_off;
- colour_off += cachep->freelist_size;
+ /* We will use last bytes at the slab for freelist */
+ freelist = addr + (PAGE_SIZE << cachep->gfporder) -
+ cachep->freelist_size;
}
- page->active = 0;
- page->s_mem = addr + colour_off;
+
return freelist;
}
((freelist_idx_t *)(page->freelist))[idx] = val;
}
-static void cache_init_objs(struct kmem_cache *cachep,
- struct page *page)
+static void cache_init_objs_debug(struct kmem_cache *cachep, struct page *page)
{
+#if DEBUG
int i;
for (i = 0; i < cachep->num; i++) {
void *objp = index_to_obj(cachep, page, i);
-#if DEBUG
+
if (cachep->flags & SLAB_STORE_USER)
*dbg_userword(cachep, objp) = NULL;
poison_obj(cachep, objp, POISON_FREE);
slab_kernel_map(cachep, objp, 0, 0);
}
-#else
- if (cachep->ctor)
- cachep->ctor(objp);
+ }
#endif
- set_obj_status(page, i, OBJECT_FREE);
+}
+
+static void cache_init_objs(struct kmem_cache *cachep,
+ struct page *page)
+{
+ int i;
+
+ cache_init_objs_debug(cachep, page);
+
+ for (i = 0; i < cachep->num; i++) {
+ /* constructor could break poison info */
+ if (DEBUG == 0 && cachep->ctor)
+ cachep->ctor(index_to_obj(cachep, page, i));
+
set_free_obj(page, i, i);
}
}
BUG_ON(objnr >= cachep->num);
BUG_ON(objp != index_to_obj(cachep, page, objnr));
- set_obj_status(page, objnr, OBJECT_FREE);
if (cachep->flags & SLAB_POISON) {
poison_obj(cachep, objp, POISON_FREE);
slab_kernel_map(cachep, objp, 0, caller);
#define cache_free_debugcheck(x,objp,z) (objp)
#endif
+static inline void fixup_slab_list(struct kmem_cache *cachep,
+ struct kmem_cache_node *n, struct page *page)
+{
+ /* move slabp to correct slabp list: */
+ list_del(&page->lru);
+ if (page->active == cachep->num)
+ list_add(&page->lru, &n->slabs_full);
+ else
+ list_add(&page->lru, &n->slabs_partial);
+}
+
static struct page *get_first_slab(struct kmem_cache_node *n)
{
struct page *page;
ac_put_obj(cachep, ac, slab_get_obj(cachep, page));
}
- /* move slabp to correct slabp list: */
- list_del(&page->lru);
- if (page->active == cachep->num)
- list_add(&page->lru, &n->slabs_full);
- else
- list_add(&page->lru, &n->slabs_partial);
+ fixup_slab_list(cachep, n, page);
}
must_grow:
static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
gfp_t flags, void *objp, unsigned long caller)
{
- struct page *page;
-
if (!objp)
return objp;
if (cachep->flags & SLAB_POISON) {
*dbg_redzone2(cachep, objp) = RED_ACTIVE;
}
- page = virt_to_head_page(objp);
- set_obj_status(page, obj_to_index(cachep, page, objp), OBJECT_ACTIVE);
objp += obj_offset(cachep);
if (cachep->ctor && cachep->flags & SLAB_POISON)
cachep->ctor(objp);
obj = slab_get_obj(cachep, page);
n->free_objects--;
- /* move slabp to correct slabp list: */
- list_del(&page->lru);
- if (page->active == cachep->num)
- list_add(&page->lru, &n->slabs_full);
- else
- list_add(&page->lru, &n->slabs_partial);
+ fixup_slab_list(cachep, n, page);
spin_unlock(&n->list_lock);
goto done;
projects / deliverable / linux.git / blobdiff