From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966178Ab3HIJ2v (ORCPT ); Fri, 9 Aug 2013 05:28:51 -0400 Received: from LGEMRELSE7Q.lge.com ([156.147.1.151]:53871 "EHLO LGEMRELSE7Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965978Ab3HIJ1R (ORCPT ); Fri, 9 Aug 2013 05:27:17 -0400 X-AuditID: 9c930197-b7b44ae00000347f-b3-5204b5ef35b1 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 v2 16/20] mm, hugetlb: move down outside_reserve check Date: Fri, 9 Aug 2013 18:26:34 +0900 Message-Id: <1376040398-11212-17-git-send-email-iamjoonsoo.kim@lge.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1376040398-11212-1-git-send-email-iamjoonsoo.kim@lge.com> References: <1376040398-11212-1-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. Signed-off-by: Joonsoo Kim diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 24de2ca..2372f75 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2499,7 +2499,7 @@ 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 */ @@ -2514,6 +2514,11 @@ retry_avoidcopy: return 0; } + page_cache_get(old_page); + + /* Drop page_table_lock as buddy allocator may be called */ + spin_unlock(&mm->page_table_lock); + /* * If the process that created a MAP_PRIVATE mapping is about to * perform a COW due to a shared page count, attempt to satisfy @@ -2527,19 +2532,17 @@ 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(&mm->page_table_lock); - chg = vma_needs_reservation(h, vma, address); - if (chg == -ENOMEM) { - page_cache_release(old_page); + if (!outside_reserve) { + chg = vma_needs_reservation(h, vma, address); + if (chg == -ENOMEM) { + page_cache_release(old_page); - /* Caller expects lock to be held */ - spin_lock(&mm->page_table_lock); - return VM_FAULT_OOM; + /* Caller expects lock to be held */ + spin_lock(&mm->page_table_lock); + 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx150.postini.com [74.125.245.150]) by kanga.kvack.org (Postfix) with SMTP id 4D45A6B006C for ; Fri, 9 Aug 2013 05:27:16 -0400 (EDT) From: Joonsoo Kim Subject: [PATCH v2 16/20] mm, hugetlb: move down outside_reserve check Date: Fri, 9 Aug 2013 18:26:34 +0900 Message-Id: <1376040398-11212-17-git-send-email-iamjoonsoo.kim@lge.com> In-Reply-To: <1376040398-11212-1-git-send-email-iamjoonsoo.kim@lge.com> References: <1376040398-11212-1-git-send-email-iamjoonsoo.kim@lge.com> Sender: owner-linux-mm@kvack.org List-ID: 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 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. Signed-off-by: Joonsoo Kim diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 24de2ca..2372f75 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2499,7 +2499,7 @@ 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 */ @@ -2514,6 +2514,11 @@ retry_avoidcopy: return 0; } + page_cache_get(old_page); + + /* Drop page_table_lock as buddy allocator may be called */ + spin_unlock(&mm->page_table_lock); + /* * If the process that created a MAP_PRIVATE mapping is about to * perform a COW due to a shared page count, attempt to satisfy @@ -2527,19 +2532,17 @@ 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(&mm->page_table_lock); - chg = vma_needs_reservation(h, vma, address); - if (chg == -ENOMEM) { - page_cache_release(old_page); + if (!outside_reserve) { + chg = vma_needs_reservation(h, vma, address); + if (chg == -ENOMEM) { + page_cache_release(old_page); - /* Caller expects lock to be held */ - spin_lock(&mm->page_table_lock); - return VM_FAULT_OOM; + /* Caller expects lock to be held */ + spin_lock(&mm->page_table_lock); + 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 -- 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