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-rw-r--r--include/linux/slub_def.h15
-rw-r--r--mm/slab.c3
-rw-r--r--mm/slub.c94
3 files changed, 75 insertions, 37 deletions
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index 5e6d3d634d5..57deecc79d5 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -71,6 +71,7 @@ struct kmem_cache {
/* Allocation and freeing of slabs */
int objects; /* Number of objects in slab */
+ gfp_t allocflags; /* gfp flags to use on each alloc */
int refcount; /* Refcount for slab cache destroy */
void (*ctor)(struct kmem_cache *, void *);
int inuse; /* Offset to metadata */
@@ -110,7 +111,7 @@ struct kmem_cache {
* We keep the general caches in an array of slab caches that are used for
* 2^x bytes of allocations.
*/
-extern struct kmem_cache kmalloc_caches[PAGE_SHIFT];
+extern struct kmem_cache kmalloc_caches[PAGE_SHIFT + 1];
/*
* Sorry that the following has to be that ugly but some versions of GCC
@@ -188,12 +189,16 @@ static __always_inline struct kmem_cache *kmalloc_slab(size_t size)
void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
void *__kmalloc(size_t size, gfp_t flags);
+static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
+{
+ return (void *)__get_free_pages(flags | __GFP_COMP, get_order(size));
+}
+
static __always_inline void *kmalloc(size_t size, gfp_t flags)
{
if (__builtin_constant_p(size)) {
- if (size > PAGE_SIZE / 2)
- return (void *)__get_free_pages(flags | __GFP_COMP,
- get_order(size));
+ if (size > PAGE_SIZE)
+ return kmalloc_large(size, flags);
if (!(flags & SLUB_DMA)) {
struct kmem_cache *s = kmalloc_slab(size);
@@ -214,7 +219,7 @@ void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
{
if (__builtin_constant_p(size) &&
- size <= PAGE_SIZE / 2 && !(flags & SLUB_DMA)) {
+ size <= PAGE_SIZE && !(flags & SLUB_DMA)) {
struct kmem_cache *s = kmalloc_slab(size);
if (!s)
diff --git a/mm/slab.c b/mm/slab.c
index 40c00dacbe4..473e6c2eaef 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2630,6 +2630,7 @@ static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp,
slabp->colouroff = colour_off;
slabp->s_mem = objp + colour_off;
slabp->nodeid = nodeid;
+ slabp->free = 0;
return slabp;
}
@@ -2683,7 +2684,6 @@ static void cache_init_objs(struct kmem_cache *cachep,
slab_bufctl(slabp)[i] = i + 1;
}
slab_bufctl(slabp)[i - 1] = BUFCTL_END;
- slabp->free = 0;
}
static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
@@ -2816,7 +2816,6 @@ static int cache_grow(struct kmem_cache *cachep,
if (!slabp)
goto opps1;
- slabp->nodeid = nodeid;
slab_map_pages(cachep, slabp, objp);
cache_init_objs(cachep, slabp);
diff --git a/mm/slub.c b/mm/slub.c
index e2989ae243b..4b3895cb90e 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -211,6 +211,8 @@ static inline void ClearSlabDebug(struct page *page)
/* Internal SLUB flags */
#define __OBJECT_POISON 0x80000000 /* Poison object */
#define __SYSFS_ADD_DEFERRED 0x40000000 /* Not yet visible via sysfs */
+#define __KMALLOC_CACHE 0x20000000 /* objects freed using kfree */
+#define __PAGE_ALLOC_FALLBACK 0x10000000 /* Allow fallback to page alloc */
/* Not all arches define cache_line_size */
#ifndef cache_line_size
@@ -308,7 +310,7 @@ static inline int is_end(void *addr)
return (unsigned long)addr & PAGE_MAPPING_ANON;
}
-void *slab_address(struct page *page)
+static void *slab_address(struct page *page)
{
return page->end - PAGE_MAPPING_ANON;
}
@@ -1078,14 +1080,7 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
struct page *page;
int pages = 1 << s->order;
- if (s->order)
- flags |= __GFP_COMP;
-
- if (s->flags & SLAB_CACHE_DMA)
- flags |= SLUB_DMA;
-
- if (s->flags & SLAB_RECLAIM_ACCOUNT)
- flags |= __GFP_RECLAIMABLE;
+ flags |= s->allocflags;
if (node == -1)
page = alloc_pages(flags, s->order);
@@ -1546,7 +1541,6 @@ load_freelist:
unlock_out:
slab_unlock(c->page);
stat(c, ALLOC_SLOWPATH);
-out:
#ifdef SLUB_FASTPATH
local_irq_restore(flags);
#endif
@@ -1581,8 +1575,24 @@ new_slab:
c->page = new;
goto load_freelist;
}
- object = NULL;
- goto out;
+#ifdef SLUB_FASTPATH
+ local_irq_restore(flags);
+#endif
+ /*
+ * No memory available.
+ *
+ * If the slab uses higher order allocs but the object is
+ * smaller than a page size then we can fallback in emergencies
+ * to the page allocator via kmalloc_large. The page allocator may
+ * have failed to obtain a higher order page and we can try to
+ * allocate a single page if the object fits into a single page.
+ * That is only possible if certain conditions are met that are being
+ * checked when a slab is created.
+ */
+ if (!(gfpflags & __GFP_NORETRY) && (s->flags & __PAGE_ALLOC_FALLBACK))
+ return kmalloc_large(s->objsize, gfpflags);
+
+ return NULL;
debug:
object = c->page->freelist;
if (!alloc_debug_processing(s, c->page, object, addr))
@@ -2329,10 +2339,33 @@ static int calculate_sizes(struct kmem_cache *s)
size = ALIGN(size, align);
s->size = size;
- s->order = calculate_order(size);
+ if ((flags & __KMALLOC_CACHE) &&
+ PAGE_SIZE / size < slub_min_objects) {
+ /*
+ * Kmalloc cache that would not have enough objects in
+ * an order 0 page. Kmalloc slabs can fallback to
+ * page allocator order 0 allocs so take a reasonably large
+ * order that will allows us a good number of objects.
+ */
+ s->order = max(slub_max_order, PAGE_ALLOC_COSTLY_ORDER);
+ s->flags |= __PAGE_ALLOC_FALLBACK;
+ s->allocflags |= __GFP_NOWARN;
+ } else
+ s->order = calculate_order(size);
+
if (s->order < 0)
return 0;
+ s->allocflags = 0;
+ if (s->order)
+ s->allocflags |= __GFP_COMP;
+
+ if (s->flags & SLAB_CACHE_DMA)
+ s->allocflags |= SLUB_DMA;
+
+ if (s->flags & SLAB_RECLAIM_ACCOUNT)
+ s->allocflags |= __GFP_RECLAIMABLE;
+
/*
* Determine the number of objects per slab
*/
@@ -2484,11 +2517,11 @@ EXPORT_SYMBOL(kmem_cache_destroy);
* Kmalloc subsystem
*******************************************************************/
-struct kmem_cache kmalloc_caches[PAGE_SHIFT] __cacheline_aligned;
+struct kmem_cache kmalloc_caches[PAGE_SHIFT + 1] __cacheline_aligned;
EXPORT_SYMBOL(kmalloc_caches);
#ifdef CONFIG_ZONE_DMA
-static struct kmem_cache *kmalloc_caches_dma[PAGE_SHIFT];
+static struct kmem_cache *kmalloc_caches_dma[PAGE_SHIFT + 1];
#endif
static int __init setup_slub_min_order(char *str)
@@ -2536,7 +2569,7 @@ static struct kmem_cache *create_kmalloc_cache(struct kmem_cache *s,
down_write(&slub_lock);
if (!kmem_cache_open(s, gfp_flags, name, size, ARCH_KMALLOC_MINALIGN,
- flags, NULL))
+ flags | __KMALLOC_CACHE, NULL))
goto panic;
list_add(&s->list, &slab_caches);
@@ -2670,9 +2703,8 @@ void *__kmalloc(size_t size, gfp_t flags)
{
struct kmem_cache *s;
- if (unlikely(size > PAGE_SIZE / 2))
- return (void *)__get_free_pages(flags | __GFP_COMP,
- get_order(size));
+ if (unlikely(size > PAGE_SIZE))
+ return kmalloc_large(size, flags);
s = get_slab(size, flags);
@@ -2688,9 +2720,8 @@ void *__kmalloc_node(size_t size, gfp_t flags, int node)
{
struct kmem_cache *s;
- if (unlikely(size > PAGE_SIZE / 2))
- return (void *)__get_free_pages(flags | __GFP_COMP,
- get_order(size));
+ if (unlikely(size > PAGE_SIZE))
+ return kmalloc_large(size, flags);
s = get_slab(size, flags);
@@ -3001,7 +3032,7 @@ void __init kmem_cache_init(void)
caches++;
}
- for (i = KMALLOC_SHIFT_LOW; i < PAGE_SHIFT; i++) {
+ for (i = KMALLOC_SHIFT_LOW; i <= PAGE_SHIFT; i++) {
create_kmalloc_cache(&kmalloc_caches[i],
"kmalloc", 1 << i, GFP_KERNEL);
caches++;
@@ -3028,7 +3059,7 @@ void __init kmem_cache_init(void)
slab_state = UP;
/* Provide the correct kmalloc names now that the caches are up */
- for (i = KMALLOC_SHIFT_LOW; i < PAGE_SHIFT; i++)
+ for (i = KMALLOC_SHIFT_LOW; i <= PAGE_SHIFT; i++)
kmalloc_caches[i]. name =
kasprintf(GFP_KERNEL, "kmalloc-%d", 1 << i);
@@ -3057,6 +3088,9 @@ static int slab_unmergeable(struct kmem_cache *s)
if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE))
return 1;
+ if ((s->flags & __PAGE_ALLOC_FALLBACK))
+ return 1;
+
if (s->ctor)
return 1;
@@ -3218,9 +3252,9 @@ void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, void *caller)
{
struct kmem_cache *s;
- if (unlikely(size > PAGE_SIZE / 2))
- return (void *)__get_free_pages(gfpflags | __GFP_COMP,
- get_order(size));
+ if (unlikely(size > PAGE_SIZE))
+ return kmalloc_large(size, gfpflags);
+
s = get_slab(size, gfpflags);
if (unlikely(ZERO_OR_NULL_PTR(s)))
@@ -3234,9 +3268,9 @@ void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
{
struct kmem_cache *s;
- if (unlikely(size > PAGE_SIZE / 2))
- return (void *)__get_free_pages(gfpflags | __GFP_COMP,
- get_order(size));
+ if (unlikely(size > PAGE_SIZE))
+ return kmalloc_large(size, gfpflags);
+
s = get_slab(size, gfpflags);
if (unlikely(ZERO_OR_NULL_PTR(s)))
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-21 02:05:03 +0000