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=-3.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,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 6F42FC282CD for ; Mon, 28 Jan 2019 14:45:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 336F52147A for ; Mon, 28 Jan 2019 14:45:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548686718; bh=VmmjCE9nv23gtn5FhnfCZit8Inds2NxcQgpLgdIXFWA=; h=From:To:Cc:Subject:Date:List-ID:From; b=WTwAYmCcBTVGPq5qQhJDzElKeXmx1CT03Nub1gGQKeCNtKx/JarURmX92OtGQWXTp XxrcZex0H39gM7n4JFpzGiasGVwQOfNjdnOGdSR2a9rY+jfPfFnsIUTQAyN7jqHGrA Ww0TBPIm1ljB96qIe4GcvNYIptroRm8T+BTWP/rs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726840AbfA1OpQ (ORCPT ); Mon, 28 Jan 2019 09:45:16 -0500 Received: from mail-ed1-f68.google.com ([209.85.208.68]:40948 "EHLO mail-ed1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726693AbfA1OpQ (ORCPT ); Mon, 28 Jan 2019 09:45:16 -0500 Received: by mail-ed1-f68.google.com with SMTP id g22so13190382edr.7 for ; Mon, 28 Jan 2019 06:45:15 -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=VmmjCE9nv23gtn5FhnfCZit8Inds2NxcQgpLgdIXFWA=; b=ptDeEMwrJ2Fs0kGjansFzmc0VXXKN0x0JmJfflPbBAJ6mhYRrBvuzYgeGkMarCtnAO 0Blj/SYqkVSLkL9fpFxQY8AwkrCqIJ4GxE1NANdk6izwLTPMWIgmwDuZe95vuJqvsg30 2bUeTAmKo0YH4IXi0MyKPMoVQkrX2pvr28yDEKLec9w+3SWLzUUHeXPFmdftnXGaUVEg Ntt3ZQuUrwaVlo8IYoJYNLUDIYS+/1ClALoCR35By8MTjofpm1Nunvp2X6wtGFwu2DpY wP77d655yHYrtm35/VQ9HrwX8S+fbYBRWkLJvTBMgPxX9h0EkYhOqPvKzSjBR9PcZqIi cW1g== X-Gm-Message-State: AJcUukfsnkBxg/l9bADlu3xCwLHtdtacpcdvzyxl0LXhkS00NQLDRdzd zVo0slFGoEcQkBFJubykfNA= X-Google-Smtp-Source: ALg8bN4zQOz65VeZcD/EvoZAlxOuVydw3aMLYl71U5hV9bAJy37VDh3kDv/DMgsa1BCH1aA2Xxwr4w== X-Received: by 2002:a50:b205:: with SMTP id o5mr21305494edd.245.1548686714588; Mon, 28 Jan 2019 06:45:14 -0800 (PST) Received: from tiehlicka.microfocus.com (prg-ext-pat.suse.com. [213.151.95.130]) by smtp.gmail.com with ESMTPSA id j8sm2919064ejr.17.2019.01.28.06.45.12 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 28 Jan 2019 06:45:13 -0800 (PST) From: Michal Hocko To: Mikhail Zaslonko , Mikhail Gavrilov Cc: Andrew Morton , Pavel Tatashin , schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, gerald.schaefer@de.ibm.com, , LKML Subject: [PATCH 0/2] mm, memory_hotplug: fix uninitialized pages fallouts. Date: Mon, 28 Jan 2019 15:45:04 +0100 Message-Id: <20190128144506.15603-1-mhocko@kernel.org> X-Mailer: git-send-email 2.20.1 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, Mikhail has posted fixes for the two bugs quite some time ago [1]. I have pushed back on those fixes because I believed that it is much better to plug the problem at the initialization time rather than play whack-a-mole all over the hotplug code and find all the places which expect the full memory section to be initialized. We have ended up with 2830bf6f05fb ("mm, memory_hotplug: initialize struct pages for the full memory section") merged and cause a regression [2][3]. The reason is that there might be memory layouts when two NUMA nodes share the same memory section so the merged fix is simply incorrect. In order to plug this hole we really have to be zone range aware in those handlers. I have split up the original patch into two. One is unchanged (patch 2) and I took a different approach for `removable' crash. It would be great if Mikhail could test it still works for his memory layout. [1] http://lkml.kernel.org/r/20181105150401.97287-2-zaslonko@linux.ibm.com [2] https://bugzilla.redhat.com/show_bug.cgi?id=1666948 [3] http://lkml.kernel.org/r/20190125163938.GA20411@dhcp22.suse.cz