From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753448Ab3LRGyT (ORCPT ); Wed, 18 Dec 2013 01:54:19 -0500 Received: from lgeamrelo01.lge.com ([156.147.1.125]:50636 "EHLO LGEAMRELO01.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753204Ab3LRGyJ (ORCPT ); Wed, 18 Dec 2013 01:54:09 -0500 X-AuditID: 9c93017d-b7c5eae000004296-d2-52b1468d0ff6 From: Joonsoo Kim To: Andrew Morton Cc: Rik van Riel , Mel Gorman , Michal Hocko , "Aneesh Kumar K.V" , KAMEZAWA Hiroyuki , Hugh Dickins , Davidlohr Bueso , David Gibson , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Joonsoo Kim , Wanpeng Li , Naoya Horiguchi , Hillf Danton , Joonsoo Kim Subject: [PATCH v3 10/14] mm, hugetlb: move down outside_reserve check Date: Wed, 18 Dec 2013 15:53:56 +0900 Message-Id: <1387349640-8071-11-git-send-email-iamjoonsoo.kim@lge.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1387349640-8071-1-git-send-email-iamjoonsoo.kim@lge.com> References: <1387349640-8071-1-git-send-email-iamjoonsoo.kim@lge.com> X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Just move down outside_reserve check and don't check vma_need_reservation() when outside_resever is true. It is slightly optimized implementation. This makes code more readable. Reviewed-by: Aneesh Kumar K.V Signed-off-by: Joonsoo Kim diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 0f56bbf..03ab285 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2576,7 +2576,7 @@ static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, struct page *old_page, *new_page; int outside_reserve = 0; long chg; - bool use_reserve; + bool use_reserve = false; unsigned long mmun_start; /* For mmu_notifiers */ unsigned long mmun_end; /* For mmu_notifiers */ @@ -2591,6 +2591,11 @@ retry_avoidcopy: return 0; } + page_cache_get(old_page); + + /* Drop page table lock as buddy allocator may be called */ + spin_unlock(ptl); + /* * If the process that created a MAP_PRIVATE mapping is about to * perform a COW due to a shared page count, attempt to satisfy @@ -2604,19 +2609,17 @@ retry_avoidcopy: old_page != pagecache_page) outside_reserve = 1; - page_cache_get(old_page); - - /* Drop page table lock as buddy allocator may be called */ - spin_unlock(ptl); - chg = vma_needs_reservation(h, vma, address); - if (chg < 0) { - page_cache_release(old_page); + if (!outside_reserve) { + chg = vma_needs_reservation(h, vma, address); + if (chg < 0) { + page_cache_release(old_page); - /* Caller expects lock to be held */ - spin_lock(ptl); - return VM_FAULT_OOM; + /* Caller expects lock to be held */ + spin_lock(ptl); + return VM_FAULT_OOM; + } + use_reserve = !chg; } - use_reserve = !chg && !outside_reserve; new_page = alloc_huge_page(vma, address, use_reserve); -- 1.7.9.5