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 4A0DFC47404 for ; Fri, 11 Oct 2019 09:57:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 27E0C214AF for ; Fri, 11 Oct 2019 09:57:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727854AbfJKJ5b (ORCPT ); Fri, 11 Oct 2019 05:57:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51556 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727628AbfJKJ5a (ORCPT ); Fri, 11 Oct 2019 05:57:30 -0400 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 6930582A498; Fri, 11 Oct 2019 09:57:30 +0000 (UTC) Received: from [10.36.118.168] (unknown [10.36.118.168]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4191A5D9C3; Fri, 11 Oct 2019 09:57:29 +0000 (UTC) Subject: Re: [PATCH] mm/page_owner: fix a crash after memory offline To: Qian Cai , akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, "mhocko@suse.com" References: <1570732366-16426-1-git-send-email-cai@lca.pw> <2e36a929-0fc7-d32a-d838-de746ff071fc@redhat.com> <1570734720.5937.32.camel@lca.pw> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: Date: Fri, 11 Oct 2019 11:57:28 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.0 MIME-Version: 1.0 In-Reply-To: <1570734720.5937.32.camel@lca.pw> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.69]); Fri, 11 Oct 2019 09:57:30 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10.10.19 21:12, Qian Cai wrote: > On Thu, 2019-10-10 at 20:55 +0200, David Hildenbrand wrote: >> On 10.10.19 20:32, Qian Cai wrote: >>> The linux-next series "mm/memory_hotplug: Shrink zones before removing >>> memory" [1] seems make a crash easier to reproduce while reading >>> /proc/pagetypeinfo after offlining a memory section. Fix it by using >>> pfn_to_online_page() in the PFN walker. >> >> Can you please rephrase the subject+description to describe the actual >> problem and drop the reference to the series? > > I'd figure it is better for you to post this as you are on the top of this whole > mess. What do you think? You mean, I found the key to an unlimited amount of undetected BUGs, so I should fix them? ;) In case you don't have time to explore all the dirty details, I can take it from here. Just let me know. -- Thanks, David / dhildenb