diff options
| author | David Rientjes <rientjes@google.com> | 2009-07-27 18:30:35 -0700 |
|---|---|---|
| committer | Pekka Enberg <penberg@cs.helsinki.fi> | 2009-07-28 10:53:09 +0300 |
| commit | 3de472138a138008b534d9587593ba83390e330a (patch) | |
| tree | 2f31ccb13c90dff68d8fd108575caa534c6c622d /mm/slub.c | |
| parent | fa5ec8a1f66f3c2a3af723abcf8085509c9ee682 (diff) | |
| download | linux-3de472138a138008b534d9587593ba83390e330a.tar.bz2 | |
slub: use size and objsize orders to disable debug flags
This patch moves the masking of debugging flags which increase a cache's
min order due to metadata when `slub_debug=O' is used from
kmem_cache_flags() to kmem_cache_open().
Instead of defining the maximum metadata size increase in a preprocessor
macro, this approach uses the cache's ->size and ->objsize members to
determine if the min order increased due to debugging options. If so,
the flags specified in the more appropriately named DEBUG_METADATA_FLAGS
are masked off.
This approach was suggested by Christoph Lameter
<cl@linux-foundation.org>.
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Diffstat (limited to 'mm/slub.c')
| -rw-r--r-- | mm/slub.c | 40 |
1 files changed, 19 insertions, 21 deletions
diff --git a/mm/slub.c b/mm/slub.c index 466089cd5deb..a465c0a09fb5 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -142,11 +142,11 @@ SLAB_POISON | SLAB_STORE_USER) /* - * Debugging flags that require metadata to be stored in the slab, up to - * DEBUG_SIZE in size. + * Debugging flags that require metadata to be stored in the slab. These get + * disabled when slub_debug=O is used and a cache's min order increases with + * metadata. */ -#define DEBUG_SIZE_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER) -#define DEBUG_SIZE (3 * sizeof(void *) + 2 * sizeof(struct track)) +#define DEBUG_METADATA_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER) /* * Set of flags that will prevent slab merging @@ -1040,27 +1040,13 @@ static unsigned long kmem_cache_flags(unsigned long objsize, unsigned long flags, const char *name, void (*ctor)(void *)) { - int debug_flags = slub_debug; - /* * Enable debugging if selected on the kernel commandline. */ - if (debug_flags) { - if (slub_debug_slabs && - strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs))) - goto out; - - /* - * Disable debugging that increases slab size if the minimum - * slab order would have increased as a result. - */ - if (disable_higher_order_debug && - get_order(objsize + DEBUG_SIZE) > get_order(objsize)) - debug_flags &= ~DEBUG_SIZE_FLAGS; + if (slub_debug && (!slub_debug_slabs || + !strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs)))) + flags |= slub_debug; - flags |= debug_flags; - } -out: return flags; } #else @@ -2488,6 +2474,18 @@ static int kmem_cache_open(struct kmem_cache *s, gfp_t gfpflags, if (!calculate_sizes(s, -1)) goto error; + if (disable_higher_order_debug) { + /* + * Disable debugging flags that store metadata if the min slab + * order increased. + */ + if (get_order(s->size) > get_order(s->objsize)) { + s->flags &= ~DEBUG_METADATA_FLAGS; + s->offset = 0; + if (!calculate_sizes(s, -1)) + goto error; + } + } /* * The larger the object size is, the more pages we want on the partial |