slub: Fix up comments
Provide comments and fix up various spelling / style issues. Signed-off-by: Christoph Lameter <clameter@sgi.com>
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d8b42bf54b
commit
6446faa2ff
2 changed files with 30 additions and 23 deletions
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@ -61,7 +61,7 @@ struct kmem_cache {
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int size; /* The size of an object including meta data */
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int objsize; /* The size of an object without meta data */
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int offset; /* Free pointer offset. */
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int order;
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int order; /* Current preferred allocation order */
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/*
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* Avoid an extra cache line for UP, SMP and for the node local to
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@ -138,11 +138,11 @@ static __always_inline int kmalloc_index(size_t size)
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if (size <= 512) return 9;
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if (size <= 1024) return 10;
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if (size <= 2 * 1024) return 11;
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if (size <= 4 * 1024) return 12;
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/*
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* The following is only needed to support architectures with a larger page
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* size than 4k.
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*/
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if (size <= 4 * 1024) return 12;
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if (size <= 8 * 1024) return 13;
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if (size <= 16 * 1024) return 14;
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if (size <= 32 * 1024) return 15;
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49
mm/slub.c
49
mm/slub.c
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@ -291,6 +291,7 @@ static inline struct kmem_cache_cpu *get_cpu_slab(struct kmem_cache *s, int cpu)
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#endif
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}
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/* Verify that a pointer has an address that is valid within a slab page */
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static inline int check_valid_pointer(struct kmem_cache *s,
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struct page *page, const void *object)
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{
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@ -619,7 +620,7 @@ static int check_bytes_and_report(struct kmem_cache *s, struct page *page,
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* A. Free pointer (if we cannot overwrite object on free)
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* B. Tracking data for SLAB_STORE_USER
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* C. Padding to reach required alignment boundary or at mininum
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* one word if debuggin is on to be able to detect writes
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* one word if debugging is on to be able to detect writes
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* before the word boundary.
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*
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* Padding is done using 0x5a (POISON_INUSE)
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@ -1268,7 +1269,7 @@ static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags)
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* may return off node objects because partial slabs are obtained
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* from other nodes and filled up.
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*
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* If /sys/slab/xx/defrag_ratio is set to 100 (which makes
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* If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes
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* defrag_ratio = 1000) then every (well almost) allocation will
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* first attempt to defrag slab caches on other nodes. This means
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* scanning over all nodes to look for partial slabs which may be
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@ -1343,9 +1344,11 @@ static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail)
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* Adding an empty slab to the partial slabs in order
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* to avoid page allocator overhead. This slab needs
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* to come after the other slabs with objects in
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* order to fill them up. That way the size of the
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* partial list stays small. kmem_cache_shrink can
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* reclaim empty slabs from the partial list.
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* so that the others get filled first. That way the
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* size of the partial list stays small.
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*
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* kmem_cache_shrink can reclaim any empty slabs from the
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* partial list.
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*/
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add_partial(n, page, 1);
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slab_unlock(page);
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@ -1368,7 +1371,7 @@ static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
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if (c->freelist)
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stat(c, DEACTIVATE_REMOTE_FREES);
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/*
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* Merge cpu freelist into freelist. Typically we get here
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* Merge cpu freelist into slab freelist. Typically we get here
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* because both freelists are empty. So this is unlikely
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* to occur.
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*/
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@ -1399,6 +1402,7 @@ static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
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/*
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* Flush cpu slab.
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*
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* Called from IPI handler with interrupts disabled.
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*/
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static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu)
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@ -1457,7 +1461,8 @@ static inline int node_match(struct kmem_cache_cpu *c, int node)
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* rest of the freelist to the lockless freelist.
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*
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* And if we were unable to get a new slab from the partial slab lists then
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* we need to allocate a new slab. This is slowest path since we may sleep.
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* we need to allocate a new slab. This is the slowest path since it involves
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* a call to the page allocator and the setup of a new slab.
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*/
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static void *__slab_alloc(struct kmem_cache *s,
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gfp_t gfpflags, int node, void *addr, struct kmem_cache_cpu *c)
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@ -1471,7 +1476,9 @@ static void *__slab_alloc(struct kmem_cache *s,
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slab_lock(c->page);
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if (unlikely(!node_match(c, node)))
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goto another_slab;
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stat(c, ALLOC_REFILL);
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load_freelist:
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object = c->page->freelist;
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if (unlikely(!object))
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@ -1616,6 +1623,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
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if (unlikely(SlabDebug(page)))
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goto debug;
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checks_ok:
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prior = object[offset] = page->freelist;
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page->freelist = object;
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@ -1630,8 +1638,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
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goto slab_empty;
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/*
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* Objects left in the slab. If it
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* was not on the partial list before
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* Objects left in the slab. If it was not on the partial list before
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* then add it.
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*/
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if (unlikely(!prior)) {
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@ -1845,13 +1852,11 @@ static unsigned long calculate_alignment(unsigned long flags,
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unsigned long align, unsigned long size)
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{
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/*
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* If the user wants hardware cache aligned objects then
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* follow that suggestion if the object is sufficiently
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* large.
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* If the user wants hardware cache aligned objects then follow that
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* suggestion if the object is sufficiently large.
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*
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* The hardware cache alignment cannot override the
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* specified alignment though. If that is greater
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* then use it.
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* The hardware cache alignment cannot override the specified
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* alignment though. If that is greater then use it.
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*/
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if ((flags & SLAB_HWCACHE_ALIGN) &&
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size > cache_line_size() / 2)
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@ -2049,6 +2054,7 @@ static struct kmem_cache_node *early_kmem_cache_node_alloc(gfp_t gfpflags,
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#endif
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init_kmem_cache_node(n);
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atomic_long_inc(&n->nr_slabs);
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/*
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* lockdep requires consistent irq usage for each lock
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* so even though there cannot be a race this early in
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@ -2301,7 +2307,7 @@ int kmem_ptr_validate(struct kmem_cache *s, const void *object)
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/*
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* We could also check if the object is on the slabs freelist.
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* But this would be too expensive and it seems that the main
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* purpose of kmem_ptr_valid is to check if the object belongs
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* purpose of kmem_ptr_valid() is to check if the object belongs
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* to a certain slab.
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*/
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return 1;
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@ -2913,7 +2919,7 @@ void __init kmem_cache_init(void)
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/*
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* Patch up the size_index table if we have strange large alignment
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* requirements for the kmalloc array. This is only the case for
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* mips it seems. The standard arches will not generate any code here.
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* MIPS it seems. The standard arches will not generate any code here.
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*
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* Largest permitted alignment is 256 bytes due to the way we
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* handle the index determination for the smaller caches.
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@ -2942,7 +2948,6 @@ void __init kmem_cache_init(void)
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kmem_size = sizeof(struct kmem_cache);
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#endif
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printk(KERN_INFO
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"SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d,"
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" CPUs=%d, Nodes=%d\n",
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@ -3039,12 +3044,15 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size,
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*/
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for_each_online_cpu(cpu)
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get_cpu_slab(s, cpu)->objsize = s->objsize;
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s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *)));
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up_write(&slub_lock);
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if (sysfs_slab_alias(s, name))
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goto err;
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return s;
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}
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s = kmalloc(kmem_size, GFP_KERNEL);
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if (s) {
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if (kmem_cache_open(s, GFP_KERNEL, name,
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@ -3927,7 +3935,6 @@ SLAB_ATTR(remote_node_defrag_ratio);
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#endif
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#ifdef CONFIG_SLUB_STATS
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static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si)
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{
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unsigned long sum = 0;
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@ -4111,8 +4118,8 @@ static struct kset *slab_kset;
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#define ID_STR_LENGTH 64
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/* Create a unique string id for a slab cache:
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* format
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* :[flags-]size:[memory address of kmemcache]
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*
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* Format :[flags-]size
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*/
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static char *create_unique_id(struct kmem_cache *s)
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{
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