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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 446F4C76191 for ; Wed, 24 Jul 2019 08:19:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0BE21229FA for ; Wed, 24 Jul 2019 08:19:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726438AbfGXITh (ORCPT ); Wed, 24 Jul 2019 04:19:37 -0400 Received: from mx2.suse.de ([195.135.220.15]:39184 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725970AbfGXITg (ORCPT ); Wed, 24 Jul 2019 04:19:36 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 86B9DAD8A; Wed, 24 Jul 2019 08:19:34 +0000 (UTC) Subject: Re: [v4 PATCH 2/2] mm: mempolicy: handle vma with unmovable pages mapped correctly in mbind To: Yang Shi , Andrew Morton Cc: mhocko@kernel.org, mgorman@techsingularity.net, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org References: <1563556862-54056-1-git-send-email-yang.shi@linux.alibaba.com> <1563556862-54056-3-git-send-email-yang.shi@linux.alibaba.com> <6c948a96-7af1-c0d2-b3df-5fe613284d4f@suse.cz> <20190722180231.b7abbe8bdb046d725bdd9e6b@linux-foundation.org> From: Vlastimil Babka Openpgp: preference=signencrypt Autocrypt: addr=vbabka@suse.cz; prefer-encrypt=mutual; keydata= mQINBFZdmxYBEADsw/SiUSjB0dM+vSh95UkgcHjzEVBlby/Fg+g42O7LAEkCYXi/vvq31JTB 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E99N/q+kEKSgSMQMJ/CYPHQJVTi4YHh1yq/qTkHRX+ortrF5VEeDJDv+SljNStIxUdroPD29 2ijoaMFTAU+uBtE14UP5F+LWdmRdEGS1Ah1NwooL27uAFllTDQxDhg/+LJ/TqB8ZuidOIy1B xVKRSg3I2m+DUTVqBy7Lixo73hnW69kSjtqCeamY/NSu6LNP+b0wAOKhwz9hBEwEHLp05+mj 5ZFJyfGsOiNUcMoO/17FO4EBxSDP3FDLllpuzlFD7SXkfJaMWYmXIlO0jLzdfwfcnDzBbPwO hBM8hvtsyq8lq8vJOxv6XD6xcTtj5Az8t2JjdUX6SF9hxJpwhBU0wrCoGDkWp4Bbv6jnF7zP Nzftr4l8RuJoywDIiJpdaNpSlXKpj/K6KrnyAI/joYc7 Message-ID: <6aeca7cf-d9da-95cc-e6dc-a10c2978c523@suse.cz> Date: Wed, 24 Jul 2019 10:19:34 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/23/19 7:35 AM, Yang Shi wrote: > > > On 7/22/19 6:02 PM, Andrew Morton wrote: >> On Mon, 22 Jul 2019 09:25:09 +0200 Vlastimil Babka wrote: >> >>>> since there may be pages off LRU temporarily. We should migrate other >>>> pages if MPOL_MF_MOVE* is specified. Set has_unmovable flag if some >>>> paged could not be not moved, then return -EIO for mbind() eventually. >>>> >>>> With this change the above test would return -EIO as expected. >>>> >>>> Cc: Vlastimil Babka >>>> Cc: Michal Hocko >>>> Cc: Mel Gorman >>>> Signed-off-by: Yang Shi >>> Reviewed-by: Vlastimil Babka >> Thanks. >> >> I'm a bit surprised that this doesn't have a cc:stable. Did we >> consider that? > > The VM_BUG just happens on 4.9, and it is enabled only by CONFIG_VM. For > post-4.9 kernel, this fixes the semantics of mbind which should be not a > regression IMHO. 4.9 is a LTS kernel, so perhaps worth trying? >> >> Also, is this patch dependent upon "mm: mempolicy: make the behavior >> consistent when MPOL_MF_MOVE* and MPOL_MF_STRICT were specified"? >> Doesn't look that way.. > > No, it depends on patch #1. > >> >> Also, I have a note that you had concerns with "mm: mempolicy: make the >> behavior consistent when MPOL_MF_MOVE* and MPOL_MF_STRICT were >> specified". What is the status now? > > Vlastimil had given his Reviewed-by. Yes, the concerns were resolved.