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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 943A6CA9EA0 for ; Wed, 23 Oct 2019 02:36:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6F898214B2 for ; Wed, 23 Oct 2019 02:36:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389016AbfJWCgu convert rfc822-to-8bit (ORCPT ); Tue, 22 Oct 2019 22:36:50 -0400 Received: from tyo161.gate.nec.co.jp ([114.179.232.161]:49935 "EHLO tyo161.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730655AbfJWCgt (ORCPT ); Tue, 22 Oct 2019 22:36:49 -0400 Received: from mailgate02.nec.co.jp ([114.179.233.122]) by tyo161.gate.nec.co.jp (8.15.1/8.15.1) with ESMTPS id x9N2aRKv011049 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Wed, 23 Oct 2019 11:36:27 +0900 Received: from mailsv02.nec.co.jp (mailgate-v.nec.co.jp [10.204.236.94]) by mailgate02.nec.co.jp (8.15.1/8.15.1) with ESMTP id x9N2aRfM032034; Wed, 23 Oct 2019 11:36:27 +0900 Received: from mail03.kamome.nec.co.jp (mail03.kamome.nec.co.jp [10.25.43.7]) by mailsv02.nec.co.jp (8.15.1/8.15.1) with ESMTP id x9N2XWcx006253; Wed, 23 Oct 2019 11:36:27 +0900 Received: from bpxc99gp.gisp.nec.co.jp ([10.38.151.147] [10.38.151.147]) by mail01b.kamome.nec.co.jp with ESMTP id BT-MMP-9712104; Wed, 23 Oct 2019 11:15:10 +0900 Received: from BPXM23GP.gisp.nec.co.jp ([10.38.151.215]) by BPXC19GP.gisp.nec.co.jp ([10.38.151.147]) with mapi id 14.03.0439.000; Wed, 23 Oct 2019 11:15:09 +0900 From: Naoya Horiguchi To: Oscar Salvador CC: Michal Hocko , "mike.kravetz@oracle.com" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" Subject: Re: [RFC PATCH v2 10/16] mm,hwpoison: Rework soft offline for free pages Thread-Topic: [RFC PATCH v2 10/16] mm,hwpoison: Rework soft offline for free pages Thread-Index: AQHVhPYxuKrdanK4Pk2pyFsBlimO86dfuBWAgATFroCAAC2WAIABDXAAgAALI4CAAAKLgIAADVAAgAAKCgCAAAdKgIAAAl2AgAEHHQA= Date: Wed, 23 Oct 2019 02:15:08 +0000 Message-ID: <20191023021508.GA29387@hori.linux.bs1.fc.nec.co.jp> References: <20191018120615.GM5017@dhcp22.suse.cz> <20191021125842.GA11330@linux> <20191021154158.GV9379@dhcp22.suse.cz> <20191022074615.GA19060@linux> <20191022082611.GD9379@dhcp22.suse.cz> <20191022083505.GA19708@linux> <20191022092256.GH9379@dhcp22.suse.cz> <20191022095852.GB20429@linux> <20191022102457.GJ9379@dhcp22.suse.cz> <20191022103319.GA21736@linux> In-Reply-To: <20191022103319.GA21736@linux> Accept-Language: en-US, ja-JP Content-Language: ja-JP X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.34.125.96] Content-Type: text/plain; charset="iso-2022-jp" Content-ID: Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-TM-AS-MML: disable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 22, 2019 at 12:33:25PM +0200, Oscar Salvador wrote: > On Tue, Oct 22, 2019 at 12:24:57PM +0200, Michal Hocko wrote: > > Yes, that makes a perfect sense. What I am saying that the migration > > (aka trying to recover) is the main and only difference. The soft > > offline should poison page tables when not able to migrate as well > > IIUC. > > Yeah, I see your point. > I do not really why soft-offline strived so much to left the page > untouched unless it was able to content the problem. > > Note that if we start now to poison pages even if we could not > content them (in soft-offline mode), that is a big and visible user > change. It's declared that soft offline never disrupts userspace by design, so if poisoning page tables in migration failure, we could break this and send SIGBUSs. Then end users would complain that their processes are killed by corrected (so non-urgent) errors. Thanks, Naoya Horiguchi