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Merge branch 'slab-linus' of git://git.kernel.org/pub/scm/linux/kerne…
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…l/git/christoph/vm

* 'slab-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/christoph/vm:
  slub: Support 4k kmallocs again to compensate for page allocator slowness
  slub: Fallback to kmalloc_large for failing higher order allocs
  slub: Determine gfpflags once and not every time a slab is allocated
  make slub.c:slab_address() static
  slub: kmalloc page allocator pass-through cleanup
  slab: avoid double initialization & do initialization in 1 place
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Linus Torvalds committed Feb 15, 2008
2 parents cead99d + 331dc55 commit f527cf4
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Showing 3 changed files with 75 additions and 37 deletions.
15 changes: 10 additions & 5 deletions include/linux/slub_def.h
View file
Expand Up @@ -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 */
Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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);
Expand All @@ -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)
Expand Down
3 changes: 1 addition & 2 deletions mm/slab.c
View file
Expand Up @@ -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;
}

Expand Down Expand Up @@ -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)
Expand Down Expand Up @@ -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);
Expand Down
94 changes: 64 additions & 30 deletions mm/slub.c
View file
Expand Up @@ -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
Expand Down Expand Up @@ -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;
}
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -1546,7 +1541,6 @@ static void *__slab_alloc(struct kmem_cache *s,
unlock_out:
slab_unlock(c->page);
stat(c, ALLOC_SLOWPATH);
out:
#ifdef SLUB_FASTPATH
local_irq_restore(flags);
#endif
Expand Down Expand Up @@ -1581,8 +1575,24 @@ static void *__slab_alloc(struct kmem_cache *s,
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))
Expand Down Expand Up @@ -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
*/
Expand Down Expand Up @@ -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)
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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);

Expand All @@ -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);

Expand Down Expand Up @@ -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++;
Expand All @@ -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);

Expand Down Expand Up @@ -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;

Expand Down Expand Up @@ -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)))
Expand All @@ -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)))
Expand Down

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