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 6A0D7C18DF5 for ; Tue, 20 Nov 2018 14:12:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3D5F3206BB for ; Tue, 20 Nov 2018 14:12:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3D5F3206BB 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 S1729199AbeKUAlr (ORCPT ); Tue, 20 Nov 2018 19:41:47 -0500 Received: from mx1.redhat.com ([209.132.183.28]:57760 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725995AbeKUAlr (ORCPT ); Tue, 20 Nov 2018 19:41:47 -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 440D036809; Tue, 20 Nov 2018 14:12:27 +0000 (UTC) Received: from localhost (ovpn-8-19.pek2.redhat.com [10.72.8.19]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6DBFF648B9; Tue, 20 Nov 2018 14:12:24 +0000 (UTC) Date: Tue, 20 Nov 2018 22:12:21 +0800 From: Baoquan He To: Michal Hocko Cc: Hugh Dickins , Vlastimil Babka , pifang@redhat.com, David Hildenbrand , linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, aarcange@redhat.com, Mel Gorman Subject: Re: Memory hotplug softlock issue Message-ID: <20181120141221.GA7386@MiWiFi-R3L-srv> References: <20181119125121.GK22247@dhcp22.suse.cz> <20181119141016.GO22247@dhcp22.suse.cz> <20181119173312.GV22247@dhcp22.suse.cz> <20181119205907.GW22247@dhcp22.suse.cz> <20181120015644.GA5727@MiWiFi-R3L-srv> <3f1a82a8-f2aa-ac5e-e6a8-057256162321@suse.cz> <20181120135803.GA3369@MiWiFi-R3L-srv> <20181120140524.GI22247@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181120140524.GI22247@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 [10.5.110.30]); Tue, 20 Nov 2018 14:12:27 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/20/18 at 03:05pm, Michal Hocko wrote: > > Yes, I applied Hugh's patch 8 hours ago, then our QE Ping operated on > > that machine, after many times of hot removing/adding, the endless > > looping during mirgrating is not seen any more. The test result for > > Hugh's patch is positive. I even suggested Ping increasing the memory > > pressure to "stress -m 250", it still succeeded to offline and remove. > > > > So I think this patch works to solve the issue. Thanks a lot for your > > help, all of you. > > This is a great news! Thanks for your swift feedback. I will go and try > to review Hugh's patch soon. Yeah. Thanks a lot for your help on debugging and narrowing down to position the cause of the issue, Michal, really appreciated! > > Meanwhile we found sometime onlining page may not add back all memory > > blocks on one memory board, then hot removing/adding them will cause > > kernel panic. I will investigate further and collect information, see if > > it's a kernel issue or udev issue. > > It would be great to get a report in a new email thread. Sure, will do after reproducing and inforamtion arranging. Thanks Baoquan