From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8C62CC4321D for ; Wed, 15 Aug 2018 18:50:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2895E21528 for ; Wed, 15 Aug 2018 18:50:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2895E21528 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727514AbeHOVnh (ORCPT ); Wed, 15 Aug 2018 17:43:37 -0400 Received: from out30-130.freemail.mail.aliyun.com ([115.124.30.130]:60210 "EHLO out30-130.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726292AbeHOVnh (ORCPT ); Wed, 15 Aug 2018 17:43:37 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R121e4;CH=green;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01f04452;MF=yang.shi@linux.alibaba.com;NM=1;PH=DS;RN=15;SR=0;TI=SMTPD_---0T6gJtNa_1534358999; Received: from e19h19392.et15sqa.tbsite.net(mailfrom:yang.shi@linux.alibaba.com fp:SMTPD_---0T6gJtNa_1534358999) by smtp.aliyun-inc.com(127.0.0.1); Thu, 16 Aug 2018 02:50:08 +0800 From: Yang Shi To: mhocko@kernel.org, willy@infradead.org, ldufour@linux.vnet.ibm.com, kirill@shutemov.name, vbabka@suse.cz, akpm@linux-foundation.org, peterz@infradead.org, mingo@redhat.com, acme@kernel.org, alexander.shishkin@linux.intel.com, jolsa@redhat.com, namhyung@kernel.org Cc: yang.shi@linux.alibaba.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [RFC v8 PATCH 4/5] mm: unmap VM_HUGETLB mappings with optimized path Date: Thu, 16 Aug 2018 02:49:49 +0800 Message-Id: <1534358990-85530-5-git-send-email-yang.shi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1534358990-85530-1-git-send-email-yang.shi@linux.alibaba.com> References: <1534358990-85530-1-git-send-email-yang.shi@linux.alibaba.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When unmapping VM_HUGETLB mappings, vm flags need to be updated. Since the vmas have been detached, so it sounds safe to update vm flags with read mmap_sem. Cc: Michal Hocko Cc: Vlastimil Babka Signed-off-by: Yang Shi --- mm/mmap.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index e92f680..3b9f734 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2812,7 +2812,6 @@ static int do_munmap_zap_rlock(struct mm_struct *mm, unsigned long start, /* * Unmapping vmas, which have: - * VM_HUGETLB or * VM_PFNMAP or * uprobes * need get done with write mmap_sem held since they may update @@ -2821,7 +2820,7 @@ static int do_munmap_zap_rlock(struct mm_struct *mm, unsigned long start, for (vma = start_vma; vma && vma->vm_start < end; vma = vma->vm_next) { if ((vma->vm_file && has_uprobes(vma, vma->vm_start, vma->vm_end)) || - (vma->vm_flags & (VM_HUGETLB | VM_PFNMAP))) + (vma->vm_flags & VM_PFNMAP)) goto regular_path; } -- 1.8.3.1