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 ce62b770e2fc5399e53dcc9c91ec5220820fc977..819f056b39c6f27100e8b89f91acc42b3c5f5bd6 100644 (file)
--- 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;
                /*