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=-3.0 required=3.0 tests=MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_GIT 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 1FCC9C43441 for ; Fri, 16 Nov 2018 08:30:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E238F2086B for ; Fri, 16 Nov 2018 08:30:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E238F2086B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.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 S2389341AbeKPSlw (ORCPT ); Fri, 16 Nov 2018 13:41:52 -0500 Received: from mail-ed1-f51.google.com ([209.85.208.51]:40390 "EHLO mail-ed1-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727405AbeKPSlw (ORCPT ); Fri, 16 Nov 2018 13:41:52 -0500 Received: by mail-ed1-f51.google.com with SMTP id d3so18356353edx.7 for ; Fri, 16 Nov 2018 00:30:32 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=dNJ+m15LciZQg8455eEFiwq59fDC0IvIzYdogCG8KR8=; b=rT28BlQrAsCqiZr+inAmias7lYnlsTGdTaj+Jko6gEDx/twzGIFwqV/t7kttCrlngN SS7biSjPdawnZrHsnf9UYNQTTWlqH1QJsR7GCL/e0kHQMPxiDDOXxhYvvAXvIi6wjKci bB2yf0hellrb6Ox+7oejLrZatqicoaNH4vBZwPa2OvncAlnOhaOPBf0tnPeIrl6BxprW gs9WjPHNjTh1E32xp6TlVuJjqi9btSlrz+I2Gw79uoQuq2nExpQuSqRsHqGoTNbmv/W4 iJMa54Cl85BWIQJaY70iYAxVHVEPWwLLqsUCNzF0inGbKMuDDz1hGLYQu2q0WQzGcKP/ 1NVA== X-Gm-Message-State: AGRZ1gIUxpQ035sN0QjkVPi7k1v4aLeQGZthryEwWLW/F22f1QwlUj9t Hl+qD5FvQ6DCqTDKxXGT5mk= X-Google-Smtp-Source: AJdET5dR7/BVul/SXsyz6L4/TIem+WYYb1wKMnbnBzxsamXQOdR6tBj3/H2oaDM/D207uoo0yeixVQ== X-Received: by 2002:a50:88c3:: with SMTP id d61-v6mr9024807edd.14.1542357031214; Fri, 16 Nov 2018 00:30:31 -0800 (PST) Received: from tiehlicka.suse.cz (prg-ext-pat.suse.com. [213.151.95.130]) by smtp.gmail.com with ESMTPSA id m13sm5305393edd.2.2018.11.16.00.30.30 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 16 Nov 2018 00:30:30 -0800 (PST) From: Michal Hocko To: Andrew Morton Cc: Oscar Salvador , Baoquan He , Anshuman Khandual , , LKML Subject: [PATCH 0/5] mm, memory_hotplug: improve memory offlining failures debugging Date: Fri, 16 Nov 2018 09:30:15 +0100 Message-Id: <20181116083020.20260-1-mhocko@kernel.org> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, this has been posted as an RFC [1]. I have screwed during rebasing so there were few compilation issues in the previous version. I have also integrated review feedback from Andrew and Anshuman. I have been promissing to improve memory offlining failures debugging for quite some time. As things stand now we get only very limited information in the kernel log when the offlining fails. It is usually only [ 1984.506184] rac1 kernel: memory offlining [mem 0x82600000000-0x8267fffffff] failed without no further details. We do not know what exactly fails and for what reason. Whenever I was forced to debug such a failure I've always had to do a debugging patch to tell me more. We can enable some tracepoints but it would be much better to get a better picture without using them. This patch series does 2 things. The first one is to make dump_page more usable by printing more information about the mapping patch 1. Then it reduces the log level from emerg to warning so that this function is usable from less critical context patch 2. Then I have added more detailed information about the offlining failure patch 4 and finally add dump_page to isolation and offlining migration paths. Patch 3 is a trivial cleanup. Does this look go to you? [1] http://lkml.kernel.org/r/20181107101830.17405-1-mhocko@kernel.org Shortlog Michal Hocko (5): mm: print more information about mapping in __dump_page mm: lower the printk loglevel for __dump_page messages mm, memory_hotplug: drop pointless block alignment checks from __offline_pages mm, memory_hotplug: print reason for the offlining failure mm, memory_hotplug: be more verbose for memory offline failures Diffstat mm/debug.c | 23 ++++++++++++++++++----- mm/memory_hotplug.c | 52 +++++++++++++++++++++++++++++++--------------------- mm/page_alloc.c | 1 + 3 files changed, 50 insertions(+), 26 deletions(-)