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 B610CC43441 for ; Tue, 20 Nov 2018 01:56:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 841AD2080C for ; Tue, 20 Nov 2018 01:56:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 841AD2080C 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 S1732720AbeKTMXb (ORCPT ); Tue, 20 Nov 2018 07:23:31 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46144 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730044AbeKTMXb (ORCPT ); Tue, 20 Nov 2018 07:23:31 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 251E03002F74; Tue, 20 Nov 2018 01:56:53 +0000 (UTC) Received: from localhost (ovpn-8-19.pek2.redhat.com [10.72.8.19]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 87AB6607D0; Tue, 20 Nov 2018 01:56:48 +0000 (UTC) Date: Tue, 20 Nov 2018 09:56:44 +0800 From: Baoquan He To: Hugh Dickins , Michal Hocko , Vlastimil Babka Cc: David Hildenbrand , linux-mm@kvack.org, pifang@redhat.com, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, aarcange@redhat.com, Mel Gorman Subject: Re: Memory hotplug softlock issue Message-ID: <20181120015644.GA5727@MiWiFi-R3L-srv> References: <20181115143204.GV23831@dhcp22.suse.cz> <20181116012433.GU2653@MiWiFi-R3L-srv> <20181116091409.GD14706@dhcp22.suse.cz> <20181119105202.GE18471@MiWiFi-R3L-srv> <20181119124033.GJ22247@dhcp22.suse.cz> <20181119125121.GK22247@dhcp22.suse.cz> <20181119141016.GO22247@dhcp22.suse.cz> <20181119173312.GV22247@dhcp22.suse.cz> <20181119205907.GW22247@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181119205907.GW22247@dhcp22.suse.cz> User-Agent: Mutt/1.9.1 (2017-09-22) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Tue, 20 Nov 2018 01:56:53 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/19/18 at 09:59pm, Michal Hocko wrote: > On Mon 19-11-18 12:34:09, Hugh Dickins wrote: > > I'm glad that I delayed, what I had then (migration_waitqueue instead > > of using page_waitqueue) was not wrong, but what I've been using the > > last couple of months is rather better (and can be put to use to solve > > similar problems in collapsing pages on huge tmpfs. but we don't need > > to get into that at this time): put_and_wait_on_page_locked(). > > > > What I have not yet done is verify it on latest kernel, and research > > the interested Cc list (Linus and Tim Chen come immediately to mind), > > and write the commit comment. I have some testing to do on the latest > > kernel today, so I'll throw put_and_wait_on_page_locked() in too, > > and post tomorrow I hope. > > Cool, it seems that Baoquan has a reliable test case to trigger the > pathological case. Yes. I will test Hugh's patch.