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 <heesub.shin@xxxxxxxxxxx> --- mm/zbud.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/zbud.c b/mm/zbud.c index 9bb4710..ad1e781 100644 --- 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); -- 1.8.3.2 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>