[PATCH] slab: fix sleeping in atomic bug

Fallback_alloc() does not do the check for GFP_WAIT as done in cache_grow(). Thus interrupts are disabled when we call kmem_getpages() which results in the failure. Duplicate the handling of GFP_WAIT in cache_grow(). Signed-off-by: Christoph Lameter <[email protected]> Cc: Jay Cliburn <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
mrcsosa · Dec 13, 2006 · dd47ea7 · dd47ea7
1 parent 6a8ba9d
commit dd47ea7
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/mm/slab.c b/mm/slab.c
@@ -3252,6 +3252,7 @@ void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
 	struct zone **z;
 	void *obj = NULL;
 	int nid;
+	gfp_t local_flags = (flags & GFP_LEVEL_MASK);
 
 retry:
 	/*
@@ -3275,7 +3276,12 @@ void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
 		 * We may trigger various forms of reclaim on the allowed
 		 * set and go into memory reserves if necessary.
 		 */
+		if (local_flags & __GFP_WAIT)
+			local_irq_enable();
+		kmem_flagcheck(cache, flags);
 		obj = kmem_getpages(cache, flags, -1);
+		if (local_flags & __GFP_WAIT)
+			local_irq_disable();
 		if (obj) {
 			/*
 			 * Insert into the appropriate per node queues