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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 4E322CA9EA0 for ; Tue, 22 Oct 2019 08:35:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2F2E6214B2 for ; Tue, 22 Oct 2019 08:35:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731142AbfJVIfZ (ORCPT ); Tue, 22 Oct 2019 04:35:25 -0400 Received: from mx2.suse.de ([195.135.220.15]:42164 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726978AbfJVIfY (ORCPT ); Tue, 22 Oct 2019 04:35:24 -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 9F613B4F5; Tue, 22 Oct 2019 08:35:20 +0000 (UTC) Date: Tue, 22 Oct 2019 10:35:17 +0200 From: Oscar Salvador To: Michal Hocko Cc: n-horiguchi@ah.jp.nec.com, 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 Message-ID: <20191022083505.GA19708@linux> References: <20191017142123.24245-1-osalvador@suse.de> <20191017142123.24245-11-osalvador@suse.de> <20191018120615.GM5017@dhcp22.suse.cz> <20191021125842.GA11330@linux> <20191021154158.GV9379@dhcp22.suse.cz> <20191022074615.GA19060@linux> <20191022082611.GD9379@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191022082611.GD9379@dhcp22.suse.cz> User-Agent: Mutt/1.10.1 (2018-07-13) 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 10:26:11AM +0200, Michal Hocko wrote: > On Tue 22-10-19 09:46:20, Oscar Salvador wrote: > [...] > > So, opposite to hard-offline, in soft-offline we do not fiddle with pages > > unless we are sure the page is not reachable anymore by any means. > > I have to say I do not follow. Is there any _real_ reason for > soft-offline to behave differenttly from MCE (hard-offline)? Yes. Do not take it as 100% true as I read that in some code/Documentation a while ago. But I think that it boils down to: soft-offline: "We have seen some erros in the underlying page, but it is still usable, so we have a chance to keep the the contents (via migration)" hard-offline: "The underlying page is dead, we cannot trust it, so we shut it down, killing whoever is holding it along the way". Am I wrong Naoya? -- Oscar Salvador SUSE L3