From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756848Ab3LEPQq (ORCPT ); Thu, 5 Dec 2013 10:16:46 -0500 Received: from g4t0016.houston.hp.com ([15.201.24.19]:20745 "EHLO g4t0016.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756431Ab3LEPQp (ORCPT ); Thu, 5 Dec 2013 10:16:45 -0500 Message-ID: <1386256309.1791.253.camel@misato.fc.hp.com> Subject: Re: [PATCH] mm, x86: Skip NUMA_NO_NODE while parsing SLIT From: Toshi Kani To: Yasuaki Ishimatsu Cc: akpm@linux-foundation.org, mingo@kernel.org, hpa@zytor.com, tglx@linutronix.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org, x86@kernel.org Date: Thu, 05 Dec 2013 08:11:49 -0700 In-Reply-To: <52A054A0.6060108@jp.fujitsu.com> References: <1386191348-4696-1-git-send-email-toshi.kani@hp.com> <52A054A0.6060108@jp.fujitsu.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.8.5 (3.8.5-2.fc19) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2013-12-05 at 19:25 +0900, Yasuaki Ishimatsu wrote: > (2013/12/05 6:09), Toshi Kani wrote: > > When ACPI SLIT table has an I/O locality (i.e. a locality unique > > to an I/O device), numa_set_distance() emits the warning message > > below. > > > > NUMA: Warning: node ids are out of bound, from=-1 to=-1 distance=10 > > > > acpi_numa_slit_init() calls numa_set_distance() with pxm_to_node(), > > which assumes that all localities have been parsed with SRAT previously. > > SRAT does not list I/O localities, where as SLIT lists all localities > > > including I/Os. Hence, pxm_to_node() returns NUMA_NO_NODE (-1) for > > an I/O locality. I/O localities are not supported and are ignored > > today, but emitting such warning message leads unnecessary confusion. > > In this case, the warning message should not be shown. But if SLIT table > is really broken, the message should be shown. Your patch seems to not care > for second case. In the second case, I assume you are worrying about the case of SLIT table with bad locality numbers. Since SLIT is a matrix of the number of localities, it is only possible by making the table bigger than necessary. Such excessive localities are safe to ignore (as they are ignored today) and regular users have nothing to concern about them. The warning message in this case may be helpful for platform vendors to test their firmware, but they have plenty of other methods to verify their SLIT table. Thanks, -Toshi