| Date | Mon, 18 Jun 2007 02:58:47 -0700 | From | clameter@sgi ... | Subject | [patch 09/26] SLUB: Do proper locking during dma slab creation |
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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>
--- mm/slub.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
Index: linux-2.6.22-rc4-mm2/mm/slub.c =================================================================== --- linux-2.6.22-rc4-mm2.orig/mm/slub.c 2007-06-17 18:12:10.000000000 -0700 +++ linux-2.6.22-rc4-mm2/mm/slub.c 2007-06-17 18:12:13.000000000 -0700 @@ -2310,8 +2310,15 @@ static struct kmem_cache *dma_kmalloc_ca 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 -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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