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| author | Sebastian Ott <sebott@linux.vnet.ibm.com> | 2014-06-04 16:07:00 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-04 16:53:58 -0700 |
| commit | 8bf8fcb07653fbaea74f96bba1e4ed0f851675ab (patch) | |
| tree | 6412234c0fea986db2c88874221c42bf56c7acff /mm/mempool.c | |
| parent | 02a8efeda894d3541c7143ed818b25b299504190 (diff) | |
| download | lwn-8bf8fcb07653fbaea74f96bba1e4ed0f851675ab.tar.gz lwn-8bf8fcb07653fbaea74f96bba1e4ed0f851675ab.zip | |
mm/mempool: warn about __GFP_ZERO usage
Memory obtained via mempool_alloc is not always zeroed even when
called with __GFP_ZERO. Add a note and VM_BUG_ON statement to make
that clear.
[akpm@linux-foundation.org: use VM_WARN_ON_ONCE]
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/mempool.c')
| -rw-r--r-- | mm/mempool.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/mempool.c b/mm/mempool.c index 905434f18c97..455d468c3a5d 100644 --- a/mm/mempool.c +++ b/mm/mempool.c @@ -192,6 +192,7 @@ EXPORT_SYMBOL(mempool_resize); * returns NULL. Note that due to preallocation, this function * *never* fails when called from process contexts. (it might * fail if called from an IRQ context.) + * Note: using __GFP_ZERO is not supported. */ void * mempool_alloc(mempool_t *pool, gfp_t gfp_mask) { @@ -200,6 +201,7 @@ void * mempool_alloc(mempool_t *pool, gfp_t gfp_mask) wait_queue_t wait; gfp_t gfp_temp; + VM_WARN_ON_ONCE(gfp_mask & __GFP_ZERO); might_sleep_if(gfp_mask & __GFP_WAIT); gfp_mask |= __GFP_NOMEMALLOC; /* don't allocate emergency reserves */ |