[GIT PULL] SLAB updates for 2.6.31-rc1

From: Pekka J Enberg
Date: Wed Jun 17 2009 - 02:10:39 EST


Hi Linus,

Here are some slab allocator updates accumulated over the past few months. The
most important one of them is the early-boot GFP_DMA allocation fix from Nick
which is required by s390 boot code.

Pekka

The following changes since commit 65795efbd380a832ae508b04dba8f8e53f0b84d9:
Linus Torvalds (1):
Merge branch 'next-i2c' of git://aeryn.fluff.org.uk/bjdooks/linux

are available in the git repository at:

ssh://master.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6 for-linus

Alexander Beregalov (1):
SLUB: fix build when !SLUB_DEBUG

Nick Piggin (1):
SLUB: Fix early boot GFP_DMA allocations

Pekka Enberg (5):
slab: document kzfree() zeroing behavior
SLUB: Out-of-memory diagnostics
SLUB: Don't print out OOM warning for __GFP_NOFAIL
Merge branches 'slab/documentation', 'slab/fixes', 'slob/cleanups' and 'slub/fixes' into for-linus
Merge branch 'slub/earlyboot' into for-linus

Ron Lee (1):
slab: fix generic PAGE_POISONING conflict with SLAB_RED_ZONE

Wu Fengguang (1):
slob: use PG_slab for identifying SLOB pages

include/linux/page-flags.h | 2 -
mm/slab.c | 9 ++++
mm/slob.c | 6 +-
mm/slub.c | 105 ++++++++++++++++++++++++++++++++++----------
mm/util.c | 4 ++
5 files changed, 98 insertions(+), 28 deletions(-)

diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index d6792f8..e2e5ce5 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -118,7 +118,6 @@ enum pageflags {
PG_savepinned = PG_dirty,

/* SLOB */
- PG_slob_page = PG_active,
PG_slob_free = PG_private,

/* SLUB */
@@ -201,7 +200,6 @@ PAGEFLAG(SavePinned, savepinned); /* Xen */
PAGEFLAG(Reserved, reserved) __CLEARPAGEFLAG(Reserved, reserved)
PAGEFLAG(SwapBacked, swapbacked) __CLEARPAGEFLAG(SwapBacked, swapbacked)

-__PAGEFLAG(SlobPage, slob_page)
__PAGEFLAG(SlobFree, slob_free)

__PAGEFLAG(SlubFrozen, slub_frozen)
diff --git a/mm/slab.c b/mm/slab.c
index f257d4d..d086923 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2308,6 +2308,15 @@ kmem_cache_create (const char *name, size_t size, size_t align,
/* really off slab. No need for manual alignment */
slab_size =
cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab);
+
+#ifdef CONFIG_PAGE_POISONING
+ /* If we're going to use the generic kernel_map_pages()
+ * poisoning, then it's going to smash the contents of
+ * the redzone and userword anyhow, so switch them off.
+ */
+ if (size % PAGE_SIZE == 0 && flags & SLAB_POISON)
+ flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
+#endif
}

cachep->colour_off = cache_line_size();
diff --git a/mm/slob.c b/mm/slob.c
index 64f6db1..c78742d 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -133,17 +133,17 @@ static LIST_HEAD(free_slob_large);
*/
static inline int is_slob_page(struct slob_page *sp)
{
- return PageSlobPage((struct page *)sp);
+ return PageSlab((struct page *)sp);
}

static inline void set_slob_page(struct slob_page *sp)
{
- __SetPageSlobPage((struct page *)sp);
+ __SetPageSlab((struct page *)sp);
}

static inline void clear_slob_page(struct slob_page *sp)
{
- __ClearPageSlobPage((struct page *)sp);
+ __ClearPageSlab((struct page *)sp);
}

static inline struct slob_page *slob_page(const void *addr)
diff --git a/mm/slub.c b/mm/slub.c
index 2701419..4c64493 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -840,6 +840,11 @@ static inline unsigned long slabs_node(struct kmem_cache *s, int node)
return atomic_long_read(&n->nr_slabs);
}

+static inline unsigned long node_nr_slabs(struct kmem_cache_node *n)
+{
+ return atomic_long_read(&n->nr_slabs);
+}
+
static inline void inc_slabs_node(struct kmem_cache *s, int node, int objects)
{
struct kmem_cache_node *n = get_node(s, node);
@@ -1058,6 +1063,8 @@ static inline unsigned long kmem_cache_flags(unsigned long objsize,

static inline unsigned long slabs_node(struct kmem_cache *s, int node)
{ return 0; }
+static inline unsigned long node_nr_slabs(struct kmem_cache_node *n)
+ { return 0; }
static inline void inc_slabs_node(struct kmem_cache *s, int node,
int objects) {}
static inline void dec_slabs_node(struct kmem_cache *s, int node,
@@ -1514,6 +1521,65 @@ static inline int node_match(struct kmem_cache_cpu *c, int node)
return 1;
}

+static int count_free(struct page *page)
+{
+ return page->objects - page->inuse;
+}
+
+static unsigned long count_partial(struct kmem_cache_node *n,
+ int (*get_count)(struct page *))
+{
+ unsigned long flags;
+ unsigned long x = 0;
+ struct page *page;
+
+ spin_lock_irqsave(&n->list_lock, flags);
+ list_for_each_entry(page, &n->partial, lru)
+ x += get_count(page);
+ spin_unlock_irqrestore(&n->list_lock, flags);
+ return x;
+}
+
+static inline unsigned long node_nr_objs(struct kmem_cache_node *n)
+{
+#ifdef CONFIG_SLUB_DEBUG
+ return atomic_long_read(&n->total_objects);
+#else
+ return 0;
+#endif
+}
+
+static noinline void
+slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid)
+{
+ int node;
+
+ printk(KERN_WARNING
+ "SLUB: Unable to allocate memory on node %d (gfp=0x%x)\n",
+ nid, gfpflags);
+ printk(KERN_WARNING " cache: %s, object size: %d, buffer size: %d, "
+ "default order: %d, min order: %d\n", s->name, s->objsize,
+ s->size, oo_order(s->oo), oo_order(s->min));
+
+ for_each_online_node(node) {
+ struct kmem_cache_node *n = get_node(s, node);
+ unsigned long nr_slabs;
+ unsigned long nr_objs;
+ unsigned long nr_free;
+
+ if (!n)
+ continue;
+
+ nr_free = count_partial(n, count_free);
+ nr_slabs = node_nr_slabs(n);
+ nr_objs = node_nr_objs(n);
+
+ printk(KERN_WARNING
+ " node %d: slabs: %ld, objs: %ld, free: %ld\n",
+ node, nr_slabs, nr_objs, nr_free);
+ }
+}
+
/*
* Slow path. The lockless freelist is empty or we need to perform
* debugging duties.
@@ -1595,6 +1661,8 @@ new_slab:
c->page = new;
goto load_freelist;
}
+ if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
+ slab_out_of_memory(s, gfpflags, node);
return NULL;
debug:
if (!alloc_debug_processing(s, c->page, object, addr))
@@ -2636,6 +2704,7 @@ static noinline struct kmem_cache *dma_kmalloc_cache(int index, gfp_t flags)
struct kmem_cache *s;
char *text;
size_t realsize;
+ unsigned long slabflags;

s = kmalloc_caches_dma[index];
if (s)
@@ -2657,10 +2726,18 @@ static noinline struct kmem_cache *dma_kmalloc_cache(int index, gfp_t flags)
(unsigned int)realsize);
s = kmalloc(kmem_size, flags & ~SLUB_DMA);

+ /*
+ * Must defer sysfs creation to a workqueue because we don't know
+ * what context we are called from. Before sysfs comes up, we don't
+ * need to do anything because our sysfs initcall will start by
+ * adding all existing slabs to sysfs.
+ */
+ slabflags = SLAB_CACHE_DMA|SLAB_NOTRACK;
+ if (slab_state >= SYSFS)
+ slabflags |= __SYSFS_ADD_DEFERRED;
+
if (!s || !text || !kmem_cache_open(s, flags, text,
- realsize, ARCH_KMALLOC_MINALIGN,
- SLAB_CACHE_DMA|SLAB_NOTRACK|__SYSFS_ADD_DEFERRED,
- NULL)) {
+ realsize, ARCH_KMALLOC_MINALIGN, slabflags, NULL)) {
kfree(s);
kfree(text);
goto unlock_out;
@@ -2669,7 +2746,8 @@ static noinline struct kmem_cache *dma_kmalloc_cache(int index, gfp_t flags)
list_add(&s->list, &slab_caches);
kmalloc_caches_dma[index] = s;

- schedule_work(&sysfs_add_work);
+ if (slab_state >= SYSFS)
+ schedule_work(&sysfs_add_work);

unlock_out:
up_write(&slub_lock);
@@ -3368,20 +3446,6 @@ void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
}

#ifdef CONFIG_SLUB_DEBUG
-static unsigned long count_partial(struct kmem_cache_node *n,
- int (*get_count)(struct page *))
-{
- unsigned long flags;
- unsigned long x = 0;
- struct page *page;
-
- spin_lock_irqsave(&n->list_lock, flags);
- list_for_each_entry(page, &n->partial, lru)
- x += get_count(page);
- spin_unlock_irqrestore(&n->list_lock, flags);
- return x;
-}
-
static int count_inuse(struct page *page)
{
return page->inuse;
@@ -3392,11 +3456,6 @@ static int count_total(struct page *page)
return page->objects;
}

-static int count_free(struct page *page)
-{
- return page->objects - page->inuse;
-}
-
static int validate_slab(struct kmem_cache *s, struct page *page,
unsigned long *map)
{
diff --git a/mm/util.c b/mm/util.c
index d5d2213..7c35ad9 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -168,6 +168,10 @@ EXPORT_SYMBOL(krealloc);
*
* The memory of the object @p points to is zeroed before freed.
* If @p is %NULL, kzfree() does nothing.
+ *
+ * Note: this function zeroes the whole allocated buffer which can be a good
+ * deal bigger than the requested buffer size passed to kmalloc(). So be
+ * careful when using this function in performance sensitive code.
*/
void kzfree(const void *p)
{
--
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