From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: Hardware Error Kernel Mini-Summit Date: Tue, 18 May 2010 00:41:34 +0200 Message-ID: <87r5laxiap.fsf@basil.nowhere.org> References: <4BF18995.6070008@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: In-Reply-To: <4BF18995.6070008@redhat.com> (Mauro Carvalho Chehab's message of "Mon\, 17 May 2010 15\:23\:17 -0300") Sender: linux-kernel-owner@vger.kernel.org To: Mauro Carvalho Chehab Cc: Linux Kernel Mailing List , bluesmoke-devel@lists.sourceforge.net, Linux Edac Mailing List , Thomas Gleixner , Ingo Molnar , Ben Woodard , Matt Domsch , Doug Thompson , Borislav Petkov , Tony Luck , Brent Young List-Id: edac.vger.kernel.org Mauro Carvalho Chehab writes: > > There is an immediate need for error reporting on NHM-EP class > systems. Just for the innocent readers who might be mislead by this: Nehalem-EP DIMM error accounting already works fine today using mcelog for most cases, including RHEL5.5 (with some limits) and RHEL6beta with no additional changes needed. In RHEL6 the daemon does the accounting and the client reports the errors separated for each DIMM and separated in uc and ce. In RHEL5 the information is in a log file and can be gotten from there. In addition the daemon supports various advanced RAS features including predictive bad page offlining and various threshold triggers. > In the specific case of Nehalem-EX, it seems that the low level driver > won't be able to use direct access to the memory controller registers, > since the uncore now uses a register index/value pair to read or write > from the memory controller. The same pair is also used by BIOS to control > the hardware. With this design, race conditions between BIOS and the OS > may happen, So, even reading data from the Memory Controller registers > is not possible. So, it will need to use some logic to communicate via > BIOS, probably via ACPI 4.0 APEI. Already done too, see http://permalink.gmane.org/gmane.linux.acpi.devel/45743 However the interface won't give you the topology you're asking for, just the errors. -Andi -- ak@linux.intel.com -- Speaking for myself only.