From a5c96d8a1c67f31ef48935a78da2d2076513842b Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Thu, 19 Jul 2007 13:17:15 -0700 Subject: [PATCH] Fix up non-NUMA SLAB configuration for zero-sized allocations I suspect Christoph tested his code only in the NUMA configuration, for the combination of SLAB+non-NUMA the zero-sized kmalloc's would not work. Of course, this would only trigger in configurations where those zero- sized allocations happen (not very common), so that may explain why it wasn't more widely noticed. Seen by by Andi Kleen under qemu, and there seems to be a report by Michael Tsirkin on it too. Cc: Andi Kleen Cc: Roland Dreier Cc: Michael S. Tsirkin Cc: Pekka Enberg Cc: Christoph Lameter Cc: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slab.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/slab.c b/mm/slab.c index 88bc6336ce..c3feeaab38 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -3690,8 +3690,8 @@ static __always_inline void *__do_kmalloc(size_t size, gfp_t flags, * functions. */ cachep = __find_general_cachep(size, flags); - if (unlikely(cachep == NULL)) - return NULL; + if (unlikely(ZERO_OR_NULL_PTR(cachep))) + return cachep; return __cache_alloc(cachep, flags, caller); } -- 2.39.5