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| 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 /include/linux/dma-fence.h | |
| parent | Linux 4.11-rc2 (diff) | |
| download | wireguard-linux-5f0d5a3ae7cff0d7fa943c199c3a2e44f23e1fac.tar.xz wireguard-linux-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 'include/linux/dma-fence.h')
| -rw-r--r-- | include/linux/dma-fence.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 6048fa404e57..a5195a7d6f77 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -229,7 +229,7 @@ static inline struct dma_fence *dma_fence_get_rcu(struct dma_fence *fence) * * Function returns NULL if no refcount could be obtained, or the fence. * This function handles acquiring a reference to a fence that may be - * reallocated within the RCU grace period (such as with SLAB_DESTROY_BY_RCU), + * reallocated within the RCU grace period (such as with SLAB_TYPESAFE_BY_RCU), * so long as the caller is using RCU on the pointer to the fence. * * An alternative mechanism is to employ a seqlock to protect a bunch of @@ -257,7 +257,7 @@ dma_fence_get_rcu_safe(struct dma_fence * __rcu *fencep) * have successfully acquire a reference to it. If it no * longer matches, we are holding a reference to some other * reallocated pointer. This is possible if the allocator - * is using a freelist like SLAB_DESTROY_BY_RCU where the + * is using a freelist like SLAB_TYPESAFE_BY_RCU where the * fence remains valid for the RCU grace period, but it * may be reallocated. When using such allocators, we are * responsible for ensuring the reference we get is to |