mm: zbud: fix condition check on allocation size

zbud_alloc() incorrectly verifies the size of allocation limit. It should deny the allocation request greater than (PAGE_SIZE - ZHDR_SIZE_ALIGNED - CHUNK_SIZE), not (PAGE_SIZE - ZHDR_SIZE_ALIGNED) which has no remaining spaces for its buddy. There is no point in spending the entire zbud page storing only a single page, since we don't have any benefits. Signed-off-by: Heesub Shin <[email protected]> Acked-by: Seth Jennings <[email protected]> Cc: Bob Liu <[email protected]> Cc: Dongjun Shin <[email protected]> Cc: Sunae Seo <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
chewitt · Jul 31, 2013 · 9d8c5b5 · 9d8c5b5
1 parent e180cf8
commit 9d8c5b5
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/mm/zbud.c b/mm/zbud.c
@@ -257,7 +257,7 @@ int zbud_alloc(struct zbud_pool *pool, int size, gfp_t gfp,
 
 	if (size <= 0 || gfp & __GFP_HIGHMEM)
 		return -EINVAL;
-	if (size > PAGE_SIZE - ZHDR_SIZE_ALIGNED)
+	if (size > PAGE_SIZE - ZHDR_SIZE_ALIGNED - CHUNK_SIZE)
 		return -ENOSPC;
 	chunks = size_to_chunks(size);
 	spin_lock(&pool->lock);