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
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index 45ca123..c8668d1 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -37,9 +37,7 @@
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 @@
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 @@
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:
diff --git a/mm/slub.c b/mm/slub.c
index 9d2e5e4..4ea7f1a 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -261,6 +261,18 @@
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 @@
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)
{
@@ -332,6 +340,21 @@
#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:
*/
#ifdef CONFIG_SLUB_DEBUG_ON
@@ -1487,7 +1510,7 @@
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 @@
}
}
-#ifdef CONFIG_CMPXCHG_LOCAL
#ifdef CONFIG_PREEMPT
/*
* Calculate the next globally unique transaction for disambiguiation
@@ -1600,17 +1622,12 @@
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 @@
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 @@
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);
@@ -1792,37 +1806,35 @@
*/
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 @@
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 @@
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 @@
{
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 @@
*/
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 @@
*/
tid = c->tid;
barrier();
-#endif
object = c->freelist;
if (unlikely(!object || !node_match(c, node)))
@@ -1927,7 +1932,6 @@
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 @@
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 @@
{
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 @@
out_unlock:
slab_unlock(page);
-#ifdef CONFIG_CMPXCHG_LOCAL
local_irq_restore(flags);
-#endif
return;
slab_empty:
@@ -2084,17 +2076,9 @@
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 @@
{
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 @@
*/
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 @@
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 @@
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 @@
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
@@ -3610,10 +3575,11 @@
/* 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);
- if (!check_object(s, page, p, SLUB_RED_INACTIVE))
- return 0;
+ 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;
}
for_each_object(p, s, addr, page->objects)
@@ -3821,8 +3787,7 @@
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))