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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 9C405C433E6 for ; Wed, 24 Mar 2021 19:00:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6FDFC61A23 for ; Wed, 24 Mar 2021 19:00:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237752AbhCXTAG (ORCPT ); Wed, 24 Mar 2021 15:00:06 -0400 Received: from outpost1.zedat.fu-berlin.de ([130.133.4.66]:52993 "EHLO outpost1.zedat.fu-berlin.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237670AbhCXS7y (ORCPT ); Wed, 24 Mar 2021 14:59:54 -0400 Received: from inpost2.zedat.fu-berlin.de ([130.133.4.69]) by outpost.zedat.fu-berlin.de (Exim 4.94) with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (envelope-from ) id 1lP8jF-001pZc-3g; Wed, 24 Mar 2021 19:59:41 +0100 Received: from p57bd9564.dip0.t-ipconnect.de ([87.189.149.100] helo=[192.168.178.139]) by inpost2.zedat.fu-berlin.de (Exim 4.94) with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (envelope-from ) id 1lP8jE-0004jc-St; Wed, 24 Mar 2021 19:59:41 +0100 Subject: Re: [PATCH] ia64: Ensure proper NUMA distance and possible map initialization To: Andrew Morton , Valentin Schneider Cc: linux-kernel@vger.kernel.org, "linux-ia64@vger.kernel.org" , debian-ia64 , "Peter Zijlstra (Intel)" , Ingo Molnar , Vincent Guittot , Dietmar Eggemann , Sergei Trofimovich , Anatoly Pugachev References: <20210318130617.896309-1-valentin.schneider@arm.com> <20210324115432.4102cd93d35a2edb1742dec7@linux-foundation.org> From: John Paul Adrian Glaubitz Message-ID: <4e45a4a0-7611-a5cc-be8f-b43d6d5b2b0c@physik.fu-berlin.de> Date: Wed, 24 Mar 2021 19:59:39 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20210324115432.4102cd93d35a2edb1742dec7@linux-foundation.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Original-Sender: glaubitz@physik.fu-berlin.de X-Originating-IP: 87.189.149.100 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi! On 3/24/21 7:54 PM, Andrew Morton wrote: > On Thu, 18 Mar 2021 13:06:17 +0000 Valentin Schneider wrote: > >> John Paul reported a warning about bogus NUMA distance values spurred by >> commit: >> >> 620a6dc40754 ("sched/topology: Make sched_init_numa() use a set for the deduplicating sort") >> >> In this case, the afflicted machine comes up with a reported 256 possible >> nodes, all of which are 0 distance away from one another. This was >> previously silently ignored, but is now caught by the aforementioned >> commit. >> >> The culprit is ia64's node_possible_map which remains unchanged from its >> initialization value of NODE_MASK_ALL. In John's case, the machine doesn't >> have any SRAT nor SLIT table, but AIUI the possible map remains untouched >> regardless of what ACPI tables end up being parsed. Thus, !online && >> possible nodes remain with a bogus distance of 0 (distances \in [0, 9] are >> "reserved and have no meaning" as per the ACPI spec). >> >> Follow x86 / drivers/base/arch_numa's example and set the possible map to >> the parsed map, which in this case seems to be the online map. >> >> Link: http://lore.kernel.org/r/255d6b5d-194e-eb0e-ecdd-97477a534441@physik.fu-berlin.de >> Fixes: 620a6dc40754 ("sched/topology: Make sched_init_numa() use a set for the deduplicating sort") >> Reported-by: John Paul Adrian Glaubitz >> Signed-off-by: Valentin Schneider >> --- >> This might need an earlier Fixes: tag, but all of this is quite old and >> dusty (the git blame rabbit hole leads me to ~2008/2007) >> > > Thanks. Is this worth a cc:stable tag? Looks like the regression was introduced 5.12-rc1, so no need for backporting. Adrian -- .''`. John Paul Adrian Glaubitz : :' : Debian Developer - glaubitz@debian.org `. `' Freie Universitaet Berlin - glaubitz@physik.fu-berlin.de `- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913