diff options
author | Christoph Lameter <clameter@sgi.com> | 2007-09-11 15:24:11 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-09-11 17:21:27 -0700 |
commit | ba0268a8b056f2ad846f1f8837a764c21bb6425e (patch) | |
tree | 93ab7d2555a98628850dbf917a43ceddef8c980c /mm/slub.c | |
parent | 4150d3f549fe2355625017b2a6ff72aec98bcef0 (diff) | |
download | op-kernel-dev-ba0268a8b056f2ad846f1f8837a764c21bb6425e.zip op-kernel-dev-ba0268a8b056f2ad846f1f8837a764c21bb6425e.tar.gz |
SLUB: accurately compare debug flags during slab cache merge
This was posted on Aug 28 and fixes an issue that could cause troubles
when slab caches >=128k are created.
http://marc.info/?l=linux-mm&m=118798149918424&w=2
Currently we simply add the debug flags unconditional when checking for a
matching slab. This creates issues for sysfs processing when slabs exist
that are exempt from debugging due to their huge size or because only a
subset of slabs was selected for debugging.
We need to only add the flags if kmem_cache_open() would also add them.
Create a function to calculate the flags that would be set
if the cache would be opened and use that function to determine
the flags before looking for a compatible slab.
[akpm@linux-foundation.org: fixlets]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Chuck Ebbert <cebbert@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/slub.c')
-rw-r--r-- | mm/slub.c | 38 |
1 files changed, 23 insertions, 15 deletions
@@ -986,7 +986,9 @@ out: __setup("slub_debug", setup_slub_debug); -static void kmem_cache_open_debug_check(struct kmem_cache *s) +static unsigned long kmem_cache_flags(unsigned long objsize, + unsigned long flags, const char *name, + void (*ctor)(void *, struct kmem_cache *, unsigned long)) { /* * The page->offset field is only 16 bit wide. This is an offset @@ -1000,19 +1002,21 @@ static void kmem_cache_open_debug_check(struct kmem_cache *s) * Debugging or ctor may create a need to move the free * pointer. Fail if this happens. */ - if (s->objsize >= 65535 * sizeof(void *)) { - BUG_ON(s->flags & (SLAB_RED_ZONE | SLAB_POISON | + if (objsize >= 65535 * sizeof(void *)) { + BUG_ON(flags & (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | SLAB_DESTROY_BY_RCU)); - BUG_ON(s->ctor); - } - else + BUG_ON(ctor); + } else { /* * Enable debugging if selected on the kernel commandline. */ if (slub_debug && (!slub_debug_slabs || - strncmp(slub_debug_slabs, s->name, + strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs)) == 0)) - s->flags |= slub_debug; + flags |= slub_debug; + } + + return flags; } #else static inline void setup_object_debug(struct kmem_cache *s, @@ -1029,7 +1033,12 @@ static inline int slab_pad_check(struct kmem_cache *s, struct page *page) static inline int check_object(struct kmem_cache *s, struct page *page, void *object, int active) { return 1; } static inline void add_full(struct kmem_cache_node *n, struct page *page) {} -static inline void kmem_cache_open_debug_check(struct kmem_cache *s) {} +static inline unsigned long kmem_cache_flags(unsigned long objsize, + unsigned long flags, const char *name, + void (*ctor)(void *, struct kmem_cache *, unsigned long)) +{ + return flags; +} #define slub_debug 0 #endif /* @@ -2088,9 +2097,8 @@ static int kmem_cache_open(struct kmem_cache *s, gfp_t gfpflags, s->name = name; s->ctor = ctor; s->objsize = size; - s->flags = flags; s->align = align; - kmem_cache_open_debug_check(s); + s->flags = kmem_cache_flags(size, flags, name, ctor); if (!calculate_sizes(s)) goto error; @@ -2660,7 +2668,7 @@ static int slab_unmergeable(struct kmem_cache *s) } static struct kmem_cache *find_mergeable(size_t size, - size_t align, unsigned long flags, + size_t align, unsigned long flags, const char *name, void (*ctor)(void *, struct kmem_cache *, unsigned long)) { struct kmem_cache *s; @@ -2674,6 +2682,7 @@ static struct kmem_cache *find_mergeable(size_t size, size = ALIGN(size, sizeof(void *)); align = calculate_alignment(flags, align, size); size = ALIGN(size, align); + flags = kmem_cache_flags(size, flags, name, NULL); list_for_each_entry(s, &slab_caches, list) { if (slab_unmergeable(s)) @@ -2682,8 +2691,7 @@ static struct kmem_cache *find_mergeable(size_t size, if (size > s->size) continue; - if (((flags | slub_debug) & SLUB_MERGE_SAME) != - (s->flags & SLUB_MERGE_SAME)) + if ((flags & SLUB_MERGE_SAME) != (s->flags & SLUB_MERGE_SAME)) continue; /* * Check if alignment is compatible. @@ -2707,7 +2715,7 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size, struct kmem_cache *s; down_write(&slub_lock); - s = find_mergeable(size, align, flags, ctor); + s = find_mergeable(size, align, flags, name, ctor); if (s) { s->refcount++; /* |