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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 D95FCC0044C for ; Wed, 7 Nov 2018 22:04:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A653D20862 for ; Wed, 7 Nov 2018 22:04:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A653D20862 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org 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 S1728322AbeKHHgp (ORCPT ); Thu, 8 Nov 2018 02:36:45 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:45572 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727945AbeKHHgf (ORCPT ); Thu, 8 Nov 2018 02:36:35 -0500 Received: from akpm3.svl.corp.google.com (unknown [104.133.8.65]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id B76EFB09; Wed, 7 Nov 2018 22:04:14 +0000 (UTC) Date: Wed, 7 Nov 2018 14:04:13 -0800 From: Andrew Morton To: Michal Hocko Cc: , Oscar Salvador , Baoquan He , LKML , Michal Hocko Subject: Re: [RFC PATCH 4/5] mm, memory_hotplug: print reason for the offlining failure Message-Id: <20181107140413.2c0061e440123be76bf419bf@linux-foundation.org> In-Reply-To: <20181107101830.17405-5-mhocko@kernel.org> References: <20181107101830.17405-1-mhocko@kernel.org> <20181107101830.17405-5-mhocko@kernel.org> X-Mailer: Sylpheed 3.6.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 7 Nov 2018 11:18:29 +0100 Michal Hocko wrote: > From: Michal Hocko > > The memory offlining failure reporting is inconsistent and insufficient. > Some error paths simply do not report the failure to the log at all. > When we do report there are no details about the reason of the failure > and there are several of them which makes memory offlining failures > hard to debug. > > Make sure that the > memory offlining [mem %#010llx-%#010llx] failed > message is printed for all failures and also provide a short textual > reason for the failure e.g. > > [ 1984.506184] rac1 kernel: memory offlining [mem 0x82600000000-0x8267fffffff] failed due to signal backoff > > this tells us that the offlining has failed because of a signal pending > aka user intervention. > > ... Some of these messages will come out looking a bit odd. > @@ -1573,7 +1576,8 @@ static int __ref __offline_pages(unsigned long start_pfn, > MIGRATE_MOVABLE, true); > if (ret) { > mem_hotplug_done(); > - return ret; > + reason = "failed to isolate range"; "memory offlining [mem ...] failed due to failed to isolate range" > + goto failed_removal > } > > arg.start_pfn = start_pfn; > @@ -1582,15 +1586,19 @@ static int __ref __offline_pages(unsigned long start_pfn, > > ret = memory_notify(MEM_GOING_OFFLINE, &arg); > ret = notifier_to_errno(ret); > - if (ret) > - goto failed_removal; > + if (ret) { > + reason = "notifiers failure"; "memory offlining [mem ...] failed due to notifiers failure" > @@ -1607,8 +1615,10 @@ static int __ref __offline_pages(unsigned long start_pfn, > * actually in order to make hugetlbfs's object counting consistent. > */ > ret = dissolve_free_huge_pages(start_pfn, end_pfn); > - if (ret) > - goto failed_removal; > + if (ret) { > + reason = "fails to disolve hugetlb pages"; "memory offlining [mem ...] failed due to fails to disolve hugetlb pages" Fix: --- a/mm/memory_hotplug.c~mm-memory_hotplug-print-reason-for-the-offlining-failure-fix +++ a/mm/memory_hotplug.c @@ -1576,7 +1576,7 @@ static int __ref __offline_pages(unsigne MIGRATE_MOVABLE, true); if (ret) { mem_hotplug_done(); - reason = "failed to isolate range"; + reason = "failure to isolate range"; goto failed_removal } @@ -1587,7 +1587,7 @@ static int __ref __offline_pages(unsigne ret = memory_notify(MEM_GOING_OFFLINE, &arg); ret = notifier_to_errno(ret); if (ret) { - reason = "notifiers failure"; + reason = "notifier failure"; goto failed_removal_isolated; } @@ -1616,7 +1616,7 @@ repeat: */ ret = dissolve_free_huge_pages(start_pfn, end_pfn); if (ret) { - reason = "fails to disolve hugetlb pages"; + reason = "failure to dissolve huge pages"; goto failed_removal_isolated; } /* check again */ _