From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx123.postini.com [74.125.245.123]) by kanga.kvack.org (Postfix) with SMTP id F3BC16B0036 for ; Mon, 22 Jul 2013 07:33:58 -0400 (EDT) Received: from epcpsbgr4.samsung.com (u144.gpu120.samsung.co.kr [203.254.230.144]) by mailout1.samsung.com (Oracle Communications Messaging Server 7u4-24.01 (7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0MQC00C7C5GLWLL0@mailout1.samsung.com> for linux-mm@kvack.org; Mon, 22 Jul 2013 20:33:57 +0900 (KST) From: Pintu Kumar Subject: [PATCH 2/2] mm: page_alloc: avoid slowpath for more than MAX_ORDER allocation. Date: Mon, 22 Jul 2013 17:02:42 +0530 Message-id: <1374492762-17735-1-git-send-email-pintu.k@samsung.com> Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org, mgorman@suse.de, jiang.liu@huawei.com, minchan@kernel.org, cody@linux.vnet.ibm.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: cpgs@samsung.com, pintu.k@samsung.com, pintu_agarwal@yahoo.com It was observed that if order is passed as more than MAX_ORDER allocation in __alloc_pages_nodemask, it will unnecessarily go to slowpath and then return failure. Since we know that more than MAX_ORDER will anyways fail, we can avoid slowpath by returning failure in nodemask itself. Signed-off-by: Pintu Kumar --- mm/page_alloc.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 202ab58..6d38e75 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1564,6 +1564,10 @@ __setup("fail_page_alloc=", setup_fail_page_alloc); static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) { + if (order >= MAX_ORDER) { + WARN_ON(!(gfp_mask & __GFP_NOWARN)); + return false; + } if (order < fail_page_alloc.min_order) return false; if (gfp_mask & __GFP_NOFAIL) -- 1.7.9.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org