diff options
| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-01-18 02:53:44 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-04-18 11:42:36 -0700 |
| commit | 5f0d5a3ae7cff0d7fa943c199c3a2e44f23e1fac (patch) | |
| tree | b7ba2116923723e193dfe7c633ec10056c6b1b53 /mm/slab.h | |
| parent | 4495c08e84729385774601b5146d51d9e5849f81 (diff) | |
| download | lwn-5f0d5a3ae7cff0d7fa943c199c3a2e44f23e1fac.tar.gz lwn-5f0d5a3ae7cff0d7fa943c199c3a2e44f23e1fac.zip | |
mm: Rename SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU
A group of Linux kernel hackers reported chasing a bug that resulted
from their assumption that SLAB_DESTROY_BY_RCU provided an existence
guarantee, that is, that no block from such a slab would be reallocated
during an RCU read-side critical section. Of course, that is not the
case. Instead, SLAB_DESTROY_BY_RCU only prevents freeing of an entire
slab of blocks.
However, there is a phrase for this, namely "type safety". This commit
therefore renames SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU in order
to avoid future instances of this sort of confusion.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <linux-mm@kvack.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
[ paulmck: Add comments mentioning the old name, as requested by Eric
Dumazet, in order to help people familiar with the old name find
the new one. ]
Acked-by: David Rientjes <rientjes@google.com>
Diffstat (limited to 'mm/slab.h')
| -rw-r--r-- | mm/slab.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/slab.h b/mm/slab.h index 65e7c3fcac72..9cfcf099709c 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -126,7 +126,7 @@ static inline unsigned long kmem_cache_flags(unsigned long object_size, /* Legal flag mask for kmem_cache_create(), for various configurations */ #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | SLAB_PANIC | \ - SLAB_DESTROY_BY_RCU | SLAB_DEBUG_OBJECTS ) + SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS ) #if defined(CONFIG_DEBUG_SLAB) #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER) @@ -415,7 +415,7 @@ static inline size_t slab_ksize(const struct kmem_cache *s) * back there or track user information then we can * only use the space before that information. */ - if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER)) + if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER)) return s->inuse; /* * Else we can use all the padding etc for the allocation |