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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6 

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  slub: Deal with hyperthetical case of PAGE_SIZE > 2M
  slub: Remove node check in slab_free
  slub: avoid label inside conditional
  slub: Make CONFIG_DEBUG_PAGE_ALLOC work with new fastpath
  slub: Avoid warning for !CONFIG_SLUB_DEBUG
  slub: Remove CONFIG_CMPXCHG_LOCAL ifdeffery
  slub: Move debug handlign in __slab_free
  slub: Move node determination out of hotpath
  slub: Eliminate repeated use of c->page through a new page variable
  slub: get_map() function to establish map of free objects in a slab
  slub: Use NUMA_NO_NODE in get_partial
  slub: Fix a typo in config name
This commit is contained in:
Linus Torvalds 2011-05-23 10:10:44 -07:00
parent 6fad2b5b64 bfb91fb650
commit 4867faab1e
2 changed files with 69 additions and 104 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
include/linux/slub_def.h
View File

@ -37,9 +37,7 @@ enum stat_item {
struct kmem_cache_cpu {
void **freelist; /* Pointer to next available object */
#ifdef CONFIG_CMPXCHG_LOCAL
unsigned long tid; /* Globally unique transaction id */
#endif
struct page *page; /* The slab from which we are allocating */
int node; /* The node of the page (or -1 for debug) */
#ifdef CONFIG_SLUB_STATS
@ -179,7 +177,8 @@ static __always_inline int kmalloc_index(size_t size)
if (size <= 4 * 1024) return 12;
/*
* The following is only needed to support architectures with a larger page
* size than 4k.
* size than 4k. We need to support 2 * PAGE_SIZE here. So for a 64k page
* size we would have to go up to 128k.
*/
if (size <= 8 * 1024) return 13;
if (size <= 16 * 1024) return 14;
@ -190,7 +189,8 @@ static __always_inline int kmalloc_index(size_t size)
if (size <= 512 * 1024) return 19;
if (size <= 1024 * 1024) return 20;
if (size <= 2 * 1024 * 1024) return 21;
return -1;
BUG();
return -1; /* Will never be reached */
/*
* What we really wanted to do and cannot do because of compiler issues is:

161
mm/slub.c
View File

@ -261,6 +261,18 @@ static inline void *get_freepointer(struct kmem_cache *s, void *object)
return *(void **)(object + s->offset);
}
static inline void *get_freepointer_safe(struct kmem_cache *s, void *object)
{
void *p;
#ifdef CONFIG_DEBUG_PAGEALLOC
probe_kernel_read(&p, (void **)(object + s->offset), sizeof(p));
#else
p = get_freepointer(s, object);
#endif
return p;
}
static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
{
*(void **)(object + s->offset) = fp;
@ -271,10 +283,6 @@ static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\
__p += (__s)->size)
/* Scan freelist */
#define for_each_free_object(__p, __s, __free) \
for (__p = (__free); __p; __p = get_freepointer((__s), __p))
/* Determine object index from a given position */
static inline int slab_index(void *p, struct kmem_cache *s, void *addr)
{
@ -331,6 +339,21 @@ static inline int oo_objects(struct kmem_cache_order_objects x)
}
#ifdef CONFIG_SLUB_DEBUG
/*
* Determine a map of object in use on a page.
*
* Slab lock or node listlock must be held to guarantee that the page does
* not vanish from under us.
*/
static void get_map(struct kmem_cache *s, struct page *page, unsigned long *map)
{
void *p;
void *addr = page_address(page);
for (p = page->freelist; p; p = get_freepointer(s, p))
set_bit(slab_index(p, s, addr), map);
}
/*
* Debug settings:
*/
@ -1487,7 +1510,7 @@ static struct page *get_partial(struct kmem_cache *s, gfp_t flags, int node)
int searchnode = (node == NUMA_NO_NODE) ? numa_node_id() : node;
page = get_partial_node(get_node(s, searchnode));
if (page || node != -1)
if (page || node != NUMA_NO_NODE)
return page;
return get_any_partial(s, flags);
@ -1540,7 +1563,6 @@ static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail)
}
}
#ifdef CONFIG_CMPXCHG_LOCAL
#ifdef CONFIG_PREEMPT
/*
* Calculate the next globally unique transaction for disambiguiation
@ -1600,17 +1622,12 @@ static inline void note_cmpxchg_failure(const char *n,
stat(s, CMPXCHG_DOUBLE_CPU_FAIL);
}
#endif
void init_kmem_cache_cpus(struct kmem_cache *s)
{
#ifdef CONFIG_CMPXCHG_LOCAL
int cpu;
for_each_possible_cpu(cpu)
per_cpu_ptr(s->cpu_slab, cpu)->tid = init_tid(cpu);
#endif
}
/*
* Remove the cpu slab
@ -1643,9 +1660,7 @@ static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
page->inuse--;
}
c->page = NULL;
#ifdef CONFIG_CMPXCHG_LOCAL
c->tid = next_tid(c->tid);
#endif
unfreeze_slab(s, page, tail);
}
@ -1779,8 +1794,7 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
unsigned long addr, struct kmem_cache_cpu *c)
{
void **object;
struct page *new;
#ifdef CONFIG_CMPXCHG_LOCAL
struct page *page;
unsigned long flags;
local_irq_save(flags);
@ -1791,38 +1805,36 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
* pointer.
*/
c = this_cpu_ptr(s->cpu_slab);
#endif
#endif
/* We handle __GFP_ZERO in the caller */
gfpflags &= ~__GFP_ZERO;
if (!c->page)
page = c->page;
if (!page)
goto new_slab;
slab_lock(c->page);
slab_lock(page);
if (unlikely(!node_match(c, node)))
goto another_slab;
stat(s, ALLOC_REFILL);
load_freelist:
object = c->page->freelist;
object = page->freelist;
if (unlikely(!object))
goto another_slab;
if (kmem_cache_debug(s))
goto debug;
c->freelist = get_freepointer(s, object);
c->page->inuse = c->page->objects;
c->page->freelist = NULL;
c->node = page_to_nid(c->page);
page->inuse = page->objects;
page->freelist = NULL;
unlock_out:
slab_unlock(c->page);
#ifdef CONFIG_CMPXCHG_LOCAL
slab_unlock(page);
c->tid = next_tid(c->tid);
local_irq_restore(flags);
#endif
stat(s, ALLOC_SLOWPATH);
return object;
@ -1830,10 +1842,11 @@ another_slab:
deactivate_slab(s, c);
new_slab:
new = get_partial(s, gfpflags, node);
if (new) {
c->page = new;
page = get_partial(s, gfpflags, node);
if (page) {
stat(s, ALLOC_FROM_PARTIAL);
c->node = page_to_nid(page);
c->page = page;
goto load_freelist;
}
@ -1841,33 +1854,35 @@ new_slab:
if (gfpflags & __GFP_WAIT)
local_irq_enable();
new = new_slab(s, gfpflags, node);
page = new_slab(s, gfpflags, node);
if (gfpflags & __GFP_WAIT)
local_irq_disable();
if (new) {
if (page) {
c = __this_cpu_ptr(s->cpu_slab);
stat(s, ALLOC_SLAB);
if (c->page)
flush_slab(s, c);
slab_lock(new);
__SetPageSlubFrozen(new);
c->page = new;
slab_lock(page);
__SetPageSlubFrozen(page);
c->node = page_to_nid(page);
c->page = page;
goto load_freelist;
}
if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
slab_out_of_memory(s, gfpflags, node);
#ifdef CONFIG_CMPXCHG_LOCAL
local_irq_restore(flags);
#endif
return NULL;
debug:
if (!alloc_debug_processing(s, c->page, object, addr))
if (!alloc_debug_processing(s, page, object, addr))
goto another_slab;
c->page->inuse++;
c->page->freelist = get_freepointer(s, object);
page->inuse++;
page->freelist = get_freepointer(s, object);
deactivate_slab(s, c);
c->page = NULL;
c->node = NUMA_NO_NODE;
goto unlock_out;
}
@ -1887,20 +1902,12 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
{
void **object;
struct kmem_cache_cpu *c;
#ifdef CONFIG_CMPXCHG_LOCAL
unsigned long tid;
#else
unsigned long flags;
#endif
if (slab_pre_alloc_hook(s, gfpflags))
return NULL;
#ifndef CONFIG_CMPXCHG_LOCAL
local_irq_save(flags);
#else
redo:
#endif
/*
* Must read kmem_cache cpu data via this cpu ptr. Preemption is
@ -1910,7 +1917,6 @@ redo:
*/
c = __this_cpu_ptr(s->cpu_slab);
#ifdef CONFIG_CMPXCHG_LOCAL
/*
* The transaction ids are globally unique per cpu and per operation on
* a per cpu queue. Thus they can be guarantee that the cmpxchg_double
@ -1919,7 +1925,6 @@ redo:
*/
tid = c->tid;
barrier();
#endif
object = c->freelist;
if (unlikely(!object || !node_match(c, node)))
@ -1927,7 +1932,6 @@ redo:
object = __slab_alloc(s, gfpflags, node, addr, c);
else {
#ifdef CONFIG_CMPXCHG_LOCAL
/*
* The cmpxchg will only match if there was no additional
* operation and if we are on the right processor.
@ -1943,21 +1947,14 @@ redo:
if (unlikely(!irqsafe_cpu_cmpxchg_double(
s->cpu_slab->freelist, s->cpu_slab->tid,
object, tid,
get_freepointer(s, object), next_tid(tid)))) {
get_freepointer_safe(s, object), next_tid(tid)))) {
note_cmpxchg_failure("slab_alloc", s, tid);
goto redo;
}
#else
c->freelist = get_freepointer(s, object);
#endif
stat(s, ALLOC_FASTPATH);
}
#ifndef CONFIG_CMPXCHG_LOCAL
local_irq_restore(flags);
#endif
if (unlikely(gfpflags & __GFP_ZERO) && object)
memset(object, 0, s->objsize);
@ -2034,18 +2031,15 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
{
void *prior;
void **object = (void *)x;
#ifdef CONFIG_CMPXCHG_LOCAL
unsigned long flags;
local_irq_save(flags);
#endif
slab_lock(page);
stat(s, FREE_SLOWPATH);
if (kmem_cache_debug(s))
goto debug;
if (kmem_cache_debug(s) && !free_debug_processing(s, page, x, addr))
goto out_unlock;
checks_ok:
prior = page->freelist;
set_freepointer(s, object, prior);
page->freelist = object;
@ -2070,9 +2064,7 @@ checks_ok:
out_unlock:
slab_unlock(page);
#ifdef CONFIG_CMPXCHG_LOCAL
local_irq_restore(flags);
#endif
return;
slab_empty:
@ -2084,17 +2076,9 @@ slab_empty:
stat(s, FREE_REMOVE_PARTIAL);
}
slab_unlock(page);
#ifdef CONFIG_CMPXCHG_LOCAL
local_irq_restore(flags);
#endif
stat(s, FREE_SLAB);
discard_slab(s, page);
return;
debug:
if (!free_debug_processing(s, page, x, addr))
goto out_unlock;
goto checks_ok;
}
/*
@ -2113,20 +2097,11 @@ static __always_inline void slab_free(struct kmem_cache *s,
{
void **object = (void *)x;
struct kmem_cache_cpu *c;
#ifdef CONFIG_CMPXCHG_LOCAL
unsigned long tid;
#else
unsigned long flags;
#endif
slab_free_hook(s, x);
#ifndef CONFIG_CMPXCHG_LOCAL
local_irq_save(flags);
#else
redo:
#endif
/*
* Determine the currently cpus per cpu slab.
@ -2136,15 +2111,12 @@ redo:
*/
c = __this_cpu_ptr(s->cpu_slab);
#ifdef CONFIG_CMPXCHG_LOCAL
tid = c->tid;
barrier();
#endif
if (likely(page == c->page && c->node != NUMA_NO_NODE)) {
if (likely(page == c->page)) {
set_freepointer(s, object, c->freelist);
#ifdef CONFIG_CMPXCHG_LOCAL
if (unlikely(!irqsafe_cpu_cmpxchg_double(
s->cpu_slab->freelist, s->cpu_slab->tid,
c->freelist, tid,
@ -2153,16 +2125,10 @@ redo:
note_cmpxchg_failure("slab_free", s, tid);
goto redo;
}
#else
c->freelist = object;
#endif
stat(s, FREE_FASTPATH);
} else
__slab_free(s, page, x, addr);
#ifndef CONFIG_CMPXCHG_LOCAL
local_irq_restore(flags);
#endif
}
void kmem_cache_free(struct kmem_cache *s, void *x)
@ -2673,9 +2639,8 @@ static void list_slab_objects(struct kmem_cache *s, struct page *page,
return;
slab_err(s, page, "%s", text);
slab_lock(page);
for_each_free_object(p, s, page->freelist)
set_bit(slab_index(p, s, addr), map);
get_map(s, page, map);
for_each_object(p, s, addr, page->objects) {
if (!test_bit(slab_index(p, s, addr), map)) {
@ -3203,7 +3168,7 @@ static void __init kmem_cache_bootstrap_fixup(struct kmem_cache *s)
list_for_each_entry(p, &n->partial, lru)
p->slab = s;
#ifdef CONFIG_SLAB_DEBUG
#ifdef CONFIG_SLUB_DEBUG
list_for_each_entry(p, &n->full, lru)
p->slab = s;
#endif
@ -3610,8 +3575,9 @@ static int validate_slab(struct kmem_cache *s, struct page *page,
/* Now we know that a valid freelist exists */
bitmap_zero(map, page->objects);
for_each_free_object(p, s, page->freelist) {
set_bit(slab_index(p, s, addr), map);
get_map(s, page, map);
for_each_object(p, s, addr, page->objects) {
if (test_bit(slab_index(p, s, addr), map))
if (!check_object(s, page, p, SLUB_RED_INACTIVE))
return 0;
}
@ -3821,8 +3787,7 @@ static void process_slab(struct loc_track *t, struct kmem_cache *s,
void *p;
bitmap_zero(map, page->objects);
for_each_free_object(p, s, page->freelist)
set_bit(slab_index(p, s, addr), map);
get_map(s, page, map);
for_each_object(p, s, addr, page->objects)
if (!test_bit(slab_index(p, s, addr), map))