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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-01-18 13:53:44 +0300 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-04-18 21:42:36 +0300 |
| commit | 5f0d5a3ae7cff0d7fa943c199c3a2e44f23e1fac (patch) | |
| tree | b7ba2116923723e193dfe7c633ec10056c6b1b53 /mm/slab_common.c | |
| parent | 4495c08e84729385774601b5146d51d9e5849f81 (diff) | |
| download | linux-5f0d5a3ae7cff0d7fa943c199c3a2e44f23e1fac.tar.xz | |
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_common.c')
| -rw-r--r-- | mm/slab_common.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/mm/slab_common.c b/mm/slab_common.c index 09d0e849b07f..01a0fe2eb332 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -39,7 +39,7 @@ static DECLARE_WORK(slab_caches_to_rcu_destroy_work, * Set of flags that will prevent slab merging */ #define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ - SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \ + SLAB_TRACE | SLAB_TYPESAFE_BY_RCU | SLAB_NOLEAKTRACE | \ SLAB_FAILSLAB | SLAB_KASAN) #define SLAB_MERGE_SAME (SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | \ @@ -500,7 +500,7 @@ static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work) struct kmem_cache *s, *s2; /* - * On destruction, SLAB_DESTROY_BY_RCU kmem_caches are put on the + * On destruction, SLAB_TYPESAFE_BY_RCU kmem_caches are put on the * @slab_caches_to_rcu_destroy list. The slab pages are freed * through RCU and and the associated kmem_cache are dereferenced * while freeing the pages, so the kmem_caches should be freed only @@ -537,7 +537,7 @@ static int shutdown_cache(struct kmem_cache *s) memcg_unlink_cache(s); list_del(&s->list); - if (s->flags & SLAB_DESTROY_BY_RCU) { + if (s->flags & SLAB_TYPESAFE_BY_RCU) { list_add_tail(&s->list, &slab_caches_to_rcu_destroy); schedule_work(&slab_caches_to_rcu_destroy_work); } else { |