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| author | Christoph Lameter <clameter@sgi.com> | 2007-07-17 04:03:25 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-17 10:23:01 -0700 |
| commit | dfce8648d64c07eade40d456d59cb4bfcbba008c (patch) | |
| tree | 7141882bd03d9848ec6299a48bc08796a8382062 /mm/slub.c | |
| parent | 2e443fd003d76394a8ceb78f079260478aa10710 (diff) | |
| download | lwn-dfce8648d64c07eade40d456d59cb4bfcbba008c.tar.gz lwn-dfce8648d64c07eade40d456d59cb4bfcbba008c.zip | |
SLUB: do proper locking during dma slab creation
We modify the kmalloc_cache_dma[] array without proper locking. Do the proper
locking and undo the dma cache creation if another processor has already
created it.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/slub.c')
| -rw-r--r-- | mm/slub.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/mm/slub.c b/mm/slub.c index 2b50b97a0fc3..f93adb915c00 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2301,8 +2301,15 @@ static noinline struct kmem_cache *dma_kmalloc_cache(int index, gfp_t flags) text = kasprintf(flags & ~SLUB_DMA, "kmalloc_dma-%d", (unsigned int)realsize); s = create_kmalloc_cache(x, text, realsize, flags); - kmalloc_caches_dma[index] = s; - return s; + down_write(&slub_lock); + if (!kmalloc_caches_dma[index]) { + kmalloc_caches_dma[index] = s; + up_write(&slub_lock); + return s; + } + up_write(&slub_lock); + kmem_cache_destroy(s); + return kmalloc_caches_dma[index]; } #endif |