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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2CF1DC433EF for ; Fri, 10 Jun 2022 07:24:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346832AbiFJHX6 (ORCPT ); Fri, 10 Jun 2022 03:23:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42114 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346820AbiFJHXm (ORCPT ); Fri, 10 Jun 2022 03:23:42 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 18BECA3391 for ; Fri, 10 Jun 2022 00:23:26 -0700 (PDT) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.53]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4LKC7c4m4jz1GCCL; Fri, 10 Jun 2022 15:21:32 +0800 (CST) Received: from [10.174.177.76] (10.174.177.76) by canpemm500002.china.huawei.com (7.192.104.244) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 10 Jun 2022 15:23:23 +0800 Subject: Re: [v3 PATCH 3/7] mm: khugepaged: remove the redundant anon vma check To: Yang Shi CC: , , , , , References: <20220606214414.736109-1-shy828301@gmail.com> <20220606214414.736109-4-shy828301@gmail.com> From: Miaohe Lin Message-ID: <3f485480-9474-4401-bc4f-fb66aac1e591@huawei.com> Date: Fri, 10 Jun 2022 15:23:23 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20220606214414.736109-4-shy828301@gmail.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.76] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/6/7 5:44, Yang Shi wrote: > The hugepage_vma_check() already checked it, so remove the redundant > check. > > Signed-off-by: Yang Shi > --- > mm/khugepaged.c | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index d0f8020164fc..7a5d1c1a1833 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -966,9 +966,6 @@ static int hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address, > return SCAN_ADDRESS_RANGE; > if (!hugepage_vma_check(vma, vma->vm_flags)) > return SCAN_VMA_CHECK; > - /* Anon VMA expected */ > - if (!vma->anon_vma || !vma_is_anonymous(vma)) > - return SCAN_VMA_CHECK; Is it possible that hugepage_vma_check returns true due to the shmem check, or file thp check since we dropped mmap_lock ? So anon vma is explicitly checked again here? Thanks! > return 0; > } > >