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=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 00F8AC43143 for ; Tue, 2 Oct 2018 14:59:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C4DE32083F for ; Tue, 2 Oct 2018 14:59:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C4DE32083F 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 S1729173AbeJBVnV (ORCPT ); Tue, 2 Oct 2018 17:43:21 -0400 Received: from mx2.suse.de ([195.135.220.15]:34772 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727113AbeJBVnV (ORCPT ); Tue, 2 Oct 2018 17:43:21 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 70DA6AF6E; Tue, 2 Oct 2018 14:59:31 +0000 (UTC) Date: Tue, 2 Oct 2018 16:59:22 +0200 From: Michal Hocko To: Michael Bringmann Cc: Tyrel Datwyler , Thomas Falcon , Kees Cook , Mathieu Malaterre , Pavel Tatashin , Nicholas Piggin , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Mauricio Faria de Oliveira , Juliet Kim , Thiago Jung Bauermann , Nathan Fontenot , Andrew Morton , YASUAKI ISHIMATSU , linuxppc-dev@lists.ozlabs.org, Dan Williams , Oscar Salvador Subject: Re: [PATCH] migration/mm: Add WARN_ON to try_offline_node Message-ID: <20181002145922.GZ18290@dhcp22.suse.cz> References: <20181001185616.11427.35521.stgit@ltcalpine2-lp9.aus.stglabs.ibm.com> <20181001202724.GL18290@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 02-10-18 09:51:40, Michael Bringmann wrote: [...] > When the device-tree affinity attributes have changed for memory, > the 'nid' affinity calculated points to a different node for the > memory block than the one used to install it, previously on the > source system. The newly calculated 'nid' affinity may not yet > be initialized on the target system. The current memory tracking > mechanisms do not record the node to which a memory block was > associated when it was added. Nathan is looking at adding this > feature to the new implementation of LMBs, but it is not there > yet, and won't be present in earlier kernels without backporting a > significant number of changes. Then the patch you have proposed here just papers over a real issue, no? IIUC then you simply do not remove the memory if you lose the race. -- Michal Hocko SUSE Labs