From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754282Ab2KMIMo (ORCPT ); Tue, 13 Nov 2012 03:12:44 -0500 Received: from mail-ie0-f174.google.com ([209.85.223.174]:59545 "EHLO mail-ie0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753247Ab2KMIMn convert rfc822-to-8bit (ORCPT ); Tue, 13 Nov 2012 03:12:43 -0500 MIME-Version: 1.0 In-Reply-To: References: Date: Tue, 13 Nov 2012 16:12:42 +0800 Message-ID: Subject: Re: ACPI and NUMA guys, please help to check if this patch is OK From: Ethan Zhao To: David Rientjes Cc: LKML , len.brown@intel.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org David, I come back to suggest the above again because I hit the same issue on another type server and that took me sometime to find out what's wrong for no clear information when validating the SLIT. That patch will not invalidate the SRAT if SLIT is bad. The patch will only suppress the optional SLIT table if the table has more or less PXM(locality) than SRAT. [PATCH] drivers/acpi/numa.c: Add localities checking code against proximity domains to slit_valid() Some buggy BIOS/ACPI will set different number to SLIT localities and SRAT proximity domains, That will make NUMA configuration invalid and kernel will output information like following NUMA:Warning:invalid distance parameter, from=-1 to=-1 distance=83 This patch adds some checking code to slit_valid() function in order to check theSLIT localities count against SRAT proximity domains number and give clear information about ACPI bug. Signed-off-by: ethan.zhao --- drivers/acpi/numa.c | 7 +++++++ 1 files changed, 7 insertions(+), 0 deletions(-) diff --git a/drivers/acpi/numa.c b/drivers/acpi/numa.c index e56f3be..55c8a8e 100644 --- a/drivers/acpi/numa.c +++ b/drivers/acpi/numa.c @@ -161,6 +161,13 @@ static __init int slit_valid(struct acpi_table_slit *slit) { int i, j; int d = slit->locality_count; + int pxd = nodes_weight(nodes_found_map); + if (pxd != d) { + printk(KERN_INFO "ACPI: BIOS bug! SLIT localities count %d doesn't equal SRAT proximity domains number %d\n", + d , pxd); + return 0; + } + for (i = 0; i < d; i++) { for (j = 0; j < d; j++) { u8 val = slit->entry[d*i + j]; -- 1.7.1 Thanks, Ethan On Thu, May 24, 2012 at 12:59 PM, ethan zhao wrote: > That is OK， > Thanks > > On Thu, May 24, 2012 at 12:45 PM, David Rientjes wrote: >> On Thu, 24 May 2012, ethan zhao wrote: >> >>> David, >>> What we can do to help improving Linux OS is only about fatal >>> error ? Can I do something to give more clear warning information and >>> easy to find the root cause ? >>> >> >> The warning you already quoted in your changelog is sufficient warning >> that the SLIT is bad and it suppresses setting that distance. Your >> change, however, completely invalidates the SRAT if the number of >> localities does not match the number of pxms. We'd much rather simply >> suppress the bad distance rather than invalidate the SRAT, especially >> considering there is nothing in the ACPI spec that requires it.