From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753843AbeEUWLC (ORCPT ); Mon, 21 May 2018 18:11:02 -0400 Received: from mail-pl0-f67.google.com ([209.85.160.67]:36183 "EHLO mail-pl0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753766AbeEUVTe (ORCPT ); Mon, 21 May 2018 17:19:34 -0400 X-Google-Smtp-Source: AB8JxZq9Iq564knrAC9jRIXK4wwf5ob5gHXV1p8Y+MoBDbQQjSL1PMqle2fTQHX8/SgXmPEdw52VBQ== Date: Mon, 21 May 2018 14:19:31 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Song Liu cc: linux-mm@kvack.org, kernel-team@fb.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/THP: use hugepage_vma_check() in khugepaged_enter_vma_merge() In-Reply-To: <20180521193853.3089484-1-songliubraving@fb.com> Message-ID: References: <20180521193853.3089484-1-songliubraving@fb.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 21 May 2018, Song Liu wrote: > khugepaged_enter_vma_merge() is using a different approach to check > whether a vma is valid for khugepaged_enter(): > > if (!vma->anon_vma) > /* > * Not yet faulted in so we will register later in the > * page fault if needed. > */ > return 0; > if (vma->vm_ops || (vm_flags & VM_NO_KHUGEPAGED)) > /* khugepaged not yet working on file or special mappings */ > return 0; > > This check has some problems. One of the obvious problems is that > it doesn't check shmem_file(), so that vma backed with shmem files > will not call khugepaged_enter(). > > This patch fixes these problems by reusing hugepage_vma_check() in > khugepaged_enter_vma_merge(). > > Signed-off-by: Song Liu Acked-by: David Rientjes