From: Pekka Enberg <penberg@cs.helsinki.fi>
Date: Wed, 24 Jun 2009 18:59:51 +0000 (+0300)
Subject: SLUB: Don't pass __GFP_FAIL for the initial allocation
X-Git-Tag: v2.6.31-rc1~5
X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=commitdiff_plain;h=ba52270d18fb17ce2cf176b35419dab1e43fe4a3

SLUB: Don't pass __GFP_FAIL for the initial allocation

SLUB uses higher order allocations by default but falls back to small
orders under memory pressure. Make sure the GFP mask used in the initial
allocation doesn't include __GFP_NOFAIL.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/slub.c b/mm/slub.c
index ce62b77..819f056 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1085,11 +1085,17 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
 {
 	struct page *page;
 	struct kmem_cache_order_objects oo = s->oo;
+	gfp_t alloc_gfp;
 
 	flags |= s->allocflags;
 
-	page = alloc_slab_page(flags | __GFP_NOWARN | __GFP_NORETRY, node,
-									oo);
+	/*
+	 * Let the initial higher-order allocation fail under memory pressure
+	 * so we fall-back to the minimum order allocation.
+	 */
+	alloc_gfp = (flags | __GFP_NOWARN | __GFP_NORETRY) & ~__GFP_NOFAIL;
+
+	page = alloc_slab_page(alloc_gfp, node, oo);
 	if (unlikely(!page)) {
 		oo = s->min;
 		/*