[GIT PULL] SLUB fixes for 2.6.26

From: Pekka J Enberg
Date: Thu Apr 17 2008 - 01:25:40 EST


Hi Linus,

Please pull the latest SLAB/SLUB git tree from:

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

Nothing fancy here, just assorted collection of small fixes and cleanups to
SLUB.

Pekka

Christoph Lameter (5):
slub: Reduce #ifdef ZONE_DMA by moving kmalloc_caches_dma near dma logic
slub: Deal with config variable dependencies
slub: Fixes to per cpu stat output in sysfs
slub: Move map/flag clearing to __free_slab
slub: No need for per node slab counters if !SLUB_DEBUG

Pekka Enberg (1):
slub: Initialize per-cpu stats

include/linux/slub_def.h | 2 +-
init/Kconfig | 2 +-
lib/Kconfig.debug | 2 +-
mm/slub.c | 97 ++++++++++++++++++++++++++++++----------------
4 files changed, 67 insertions(+), 36 deletions(-)

diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index b00c1c7..79d59c9 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -45,9 +45,9 @@ struct kmem_cache_cpu {
struct kmem_cache_node {
spinlock_t list_lock; /* Protect partial list and nr_partial */
unsigned long nr_partial;
- atomic_long_t nr_slabs;
struct list_head partial;
#ifdef CONFIG_SLUB_DEBUG
+ atomic_long_t nr_slabs;
struct list_head full;
#endif
};
diff --git a/init/Kconfig b/init/Kconfig
index a97924b..7fccf09 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -763,7 +763,7 @@ endmenu # General setup
config SLABINFO
bool
depends on PROC_FS
- depends on SLAB || SLUB
+ depends on SLAB || SLUB_DEBUG
default y

config RT_MUTEXES
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 0796c1a..eef557d 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -211,7 +211,7 @@ config SLUB_DEBUG_ON
config SLUB_STATS
default n
bool "Enable SLUB performance statistics"
- depends on SLUB
+ depends on SLUB && SLUB_DEBUG && SYSFS
help
SLUB statistics are useful to debug SLUBs allocation behavior in
order find ways to optimize the allocator. This should never be
diff --git a/mm/slub.c b/mm/slub.c
index acc975f..7f8aaa2 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -837,6 +837,35 @@ static void remove_full(struct kmem_cache *s, struct page *page)
spin_unlock(&n->list_lock);
}

+/* Tracking of the number of slabs for debugging purposes */
+static inline unsigned long slabs_node(struct kmem_cache *s, int node)
+{
+ struct kmem_cache_node *n = get_node(s, node);
+
+ return atomic_long_read(&n->nr_slabs);
+}
+
+static inline void inc_slabs_node(struct kmem_cache *s, int node)
+{
+ struct kmem_cache_node *n = get_node(s, node);
+
+ /*
+ * May be called early in order to allocate a slab for the
+ * kmem_cache_node structure. Solve the chicken-egg
+ * dilemma by deferring the increment of the count during
+ * bootstrap (see early_kmem_cache_node_alloc).
+ */
+ if (!NUMA_BUILD || n)
+ atomic_long_inc(&n->nr_slabs);
+}
+static inline void dec_slabs_node(struct kmem_cache *s, int node)
+{
+ struct kmem_cache_node *n = get_node(s, node);
+
+ atomic_long_dec(&n->nr_slabs);
+}
+
+/* Object debug checks for alloc/free paths */
static void setup_object_debug(struct kmem_cache *s, struct page *page,
void *object)
{
@@ -1028,6 +1057,11 @@ static inline unsigned long kmem_cache_flags(unsigned long objsize,
return flags;
}
#define slub_debug 0
+
+static inline unsigned long slabs_node(struct kmem_cache *s, int node)
+ { return 0; }
+static inline void inc_slabs_node(struct kmem_cache *s, int node) {}
+static inline void dec_slabs_node(struct kmem_cache *s, int node) {}
#endif
/*
* Slab allocation and freeing
@@ -1066,7 +1100,6 @@ static void setup_object(struct kmem_cache *s, struct page *page,
static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
{
struct page *page;
- struct kmem_cache_node *n;
void *start;
void *last;
void *p;
@@ -1078,9 +1111,7 @@ static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
if (!page)
goto out;

- n = get_node(s, page_to_nid(page));
- if (n)
- atomic_long_inc(&n->nr_slabs);
+ inc_slabs_node(s, page_to_nid(page));
page->slab = s;
page->flags |= 1 << PG_slab;
if (s->flags & (SLAB_DEBUG_FREE | SLAB_RED_ZONE | SLAB_POISON |
@@ -1125,6 +1156,8 @@ static void __free_slab(struct kmem_cache *s, struct page *page)
NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
-pages);

+ __ClearPageSlab(page);
+ reset_page_mapcount(page);
__free_pages(page, s->order);
}

@@ -1151,11 +1184,7 @@ static void free_slab(struct kmem_cache *s, struct page *page)

static void discard_slab(struct kmem_cache *s, struct page *page)
{
- struct kmem_cache_node *n = get_node(s, page_to_nid(page));
-
- atomic_long_dec(&n->nr_slabs);
- reset_page_mapcount(page);
- __ClearPageSlab(page);
+ dec_slabs_node(s, page_to_nid(page));
free_slab(s, page);
}

@@ -1886,15 +1915,18 @@ static void init_kmem_cache_cpu(struct kmem_cache *s,
c->node = 0;
c->offset = s->offset / sizeof(void *);
c->objsize = s->objsize;
+#ifdef CONFIG_SLUB_STATS
+ memset(c->stat, 0, NR_SLUB_STAT_ITEMS * sizeof(unsigned));
+#endif
}

static void init_kmem_cache_node(struct kmem_cache_node *n)
{
n->nr_partial = 0;
- atomic_long_set(&n->nr_slabs, 0);
spin_lock_init(&n->list_lock);
INIT_LIST_HEAD(&n->partial);
#ifdef CONFIG_SLUB_DEBUG
+ atomic_long_set(&n->nr_slabs, 0);
INIT_LIST_HEAD(&n->full);
#endif
}
@@ -2063,7 +2095,7 @@ static struct kmem_cache_node *early_kmem_cache_node_alloc(gfp_t gfpflags,
init_tracking(kmalloc_caches, n);
#endif
init_kmem_cache_node(n);
- atomic_long_inc(&n->nr_slabs);
+ inc_slabs_node(kmalloc_caches, node);

/*
* lockdep requires consistent irq usage for each lock
@@ -2376,7 +2408,7 @@ static inline int kmem_cache_close(struct kmem_cache *s)
struct kmem_cache_node *n = get_node(s, node);

n->nr_partial -= free_list(s, n, &n->partial);
- if (atomic_long_read(&n->nr_slabs))
+ if (slabs_node(s, node))
return 1;
}
free_kmem_cache_nodes(s);
@@ -2409,10 +2441,6 @@ EXPORT_SYMBOL(kmem_cache_destroy);
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 + 1];
-#endif
-
static int __init setup_slub_min_order(char *str)
{
get_option(&str, &slub_min_order);
@@ -2472,6 +2500,7 @@ panic:
}

#ifdef CONFIG_ZONE_DMA
+static struct kmem_cache *kmalloc_caches_dma[PAGE_SHIFT + 1];

static void sysfs_add_func(struct work_struct *w)
{
@@ -2688,21 +2717,6 @@ void kfree(const void *x)
}
EXPORT_SYMBOL(kfree);

-#if defined(CONFIG_SLUB_DEBUG) || defined(CONFIG_SLABINFO)
-static unsigned long count_partial(struct kmem_cache_node *n)
-{
- 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 += page->inuse;
- spin_unlock_irqrestore(&n->list_lock, flags);
- return x;
-}
-#endif
-
/*
* kmem_cache_shrink removes empty slabs from the partial lists and sorts
* the remaining slabs by the number of items in use. The slabs with the
@@ -2816,7 +2830,7 @@ static void slab_mem_offline_callback(void *arg)
* and offline_pages() function shoudn't call this
* callback. So, we must fail.
*/
- BUG_ON(atomic_long_read(&n->nr_slabs));
+ BUG_ON(slabs_node(s, offline_node));

s->node[offline_node] = NULL;
kmem_cache_free(kmalloc_caches, n);
@@ -3181,6 +3195,21 @@ void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
return slab_alloc(s, gfpflags, node, caller);
}

+#if (defined(CONFIG_SYSFS) && defined(CONFIG_SLUB_DEBUG)) || defined(CONFIG_SLABINFO)
+static unsigned long count_partial(struct kmem_cache_node *n)
+{
+ 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 += page->inuse;
+ spin_unlock_irqrestore(&n->list_lock, flags);
+ return x;
+}
+#endif
+
#if defined(CONFIG_SYSFS) && defined(CONFIG_SLUB_DEBUG)
static int validate_slab(struct kmem_cache *s, struct page *page,
unsigned long *map)
@@ -3979,10 +4008,12 @@ static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si)

len = sprintf(buf, "%lu", sum);

+#ifdef CONFIG_SMP
for_each_online_cpu(cpu) {
if (data[cpu] && len < PAGE_SIZE - 20)
- len += sprintf(buf + len, " c%d=%u", cpu, data[cpu]);
+ len += sprintf(buf + len, " C%d=%u", cpu, data[cpu]);
}
+#endif
kfree(data);
return len + sprintf(buf + len, "\n");
}
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