From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752966AbbJLCkc (ORCPT ); Sun, 11 Oct 2015 22:40:32 -0400 Received: from mail-pa0-f67.google.com ([209.85.220.67]:33586 "EHLO mail-pa0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752668AbbJLCkb (ORCPT ); Sun, 11 Oct 2015 22:40:31 -0400 From: yalin wang To: akpm@linux-foundation.org, vbabka@suse.cz, mgorman@techsingularity.net, mhocko@suse.com, rientjes@google.com, js1304@gmail.com, kirill.shutemov@linux.intel.com, hannes@cmpxchg.org, alexander.h.duyck@redhat.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: yalin wang Subject: [RFC] mm: fix a BUG, the page is allocated 2 times Date: Mon, 12 Oct 2015 10:40:06 +0800 Message-Id: <1444617606-8685-1-git-send-email-yalin.wang2010@gmail.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Remove unlikely(order), because we are sure order is not zero if code reach here, also add if (page == NULL), only allocate page again if __rmqueue_smallest() failed or alloc_flags & ALLOC_HARDER == 0 Signed-off-by: yalin wang --- mm/page_alloc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 0d6f540..de82e2c 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2241,13 +2241,13 @@ struct page *buffered_rmqueue(struct zone *preferred_zone, spin_lock_irqsave(&zone->lock, flags); page = NULL; - if (unlikely(order) && (alloc_flags & ALLOC_HARDER)) { + if (alloc_flags & ALLOC_HARDER) { page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC); if (page) trace_mm_page_alloc_zone_locked(page, order, migratetype); } - - page = __rmqueue(zone, order, migratetype, gfp_flags); + if (page == NULL) + page = __rmqueue(zone, order, migratetype, gfp_flags); spin_unlock(&zone->lock); if (!page) goto failed; -- 1.9.1