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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 3C3EBC0044C for ; Tue, 6 Nov 2018 00:22:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0234620827 for ; Tue, 6 Nov 2018 00:22:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0234620827 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727200AbeKFJon (ORCPT ); Tue, 6 Nov 2018 04:44:43 -0500 Received: from mx1.redhat.com ([209.132.183.28]:49464 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725796AbeKFJon (ORCPT ); Tue, 6 Nov 2018 04:44:43 -0500 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2C0F931256BA; Tue, 6 Nov 2018 00:22:21 +0000 (UTC) Received: from localhost (ovpn-8-18.pek2.redhat.com [10.72.8.18]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5C90266061; Tue, 6 Nov 2018 00:22:20 +0000 (UTC) Date: Tue, 6 Nov 2018 08:22:16 +0800 From: Baoquan He To: Michal Hocko Cc: Andrew Morton , linux-mm@kvack.org, LKML , Stable tree Subject: Re: [PATCH] mm, memory_hotplug: teach has_unmovable_pages about of LRU migrateable pages Message-ID: <20181106002216.GK27491@MiWiFi-R3L-srv> References: <20181101091055.GA15166@MiWiFi-R3L-srv> <20181102155528.20358-1-mhocko@kernel.org> <20181105002009.GF27491@MiWiFi-R3L-srv> <20181105091407.GB4361@dhcp22.suse.cz> <20181105092851.GD4361@dhcp22.suse.cz> <20181105102520.GB22011@MiWiFi-R3L-srv> <20181105123837.GH4361@dhcp22.suse.cz> <20181105142308.GJ27491@MiWiFi-R3L-srv> <20181105171002.GO4361@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181105171002.GO4361@dhcp22.suse.cz> User-Agent: Mutt/1.9.1 (2017-09-22) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Tue, 06 Nov 2018 00:22:21 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/05/18 at 06:10pm, Michal Hocko wrote: > On Mon 05-11-18 22:23:08, Baoquan He wrote: > > On 11/05/18 at 01:38pm, Michal Hocko wrote: > > > On Mon 05-11-18 18:25:20, Baoquan He wrote: > > > > Hi Michal, > > > > > > > > On 11/05/18 at 10:28am, Michal Hocko wrote: > > > > > > > > > > Or something like this. Ugly as hell, no question about that. I also > > > > > have to think about this some more to convince myself this will not > > > > > result in an endless loop under some situations. > > > > > > > > It failed. Paste the log and patch diff here, please help check if I made > > > > any mistake on manual code change. The log is at bottom. > > > > > > The retry patch is obviously still racy, it just makes the race window > > > slightly smaller and I hoped it would catch most of those races but this > > > is obviously not the case. > > > > > > I was thinking about your MIGRATE_MOVABLE check some more and I still do > > > not like it much, we just change migrate type at many places and I have > > > hard time to actually see this is always safe wrt. to what we need here. > > > > > > We should be able to restore the zone type check though. The > > > primary problem fixed by 15c30bc09085 ("mm, memory_hotplug: make > > > has_unmovable_pages more robust") was that early allocations made it to > > > the zone_movable range. If we add the check _after_ the PageReserved() > > > check then we should be able to rule all bootmem allocation out. > > > > > > So what about the following (on top of the previous patch which makes > > > sense on its own I believe). > > > > Yes, I think this looks very reasonable and should be robust. > > > > Have tested it, hot removing 4 hotpluggable nodes continusously > > succeeds, and then hot adding them back, still works well. > > > > So please feel free to add my Tested-by or Acked-by. > > > > Tested-by: Baoquan He > > or > > Acked-by: Baoquan He > > Thanks for retesting! Does this apply to both patches? Sorry, don't get it. I just applied this on top of linus's tree and tested. Do you mean applying it on top of previous code change?