From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <5208D80D.5030206@linux.vnet.ibm.com> Date: Mon, 12 Aug 2013 18:11:49 +0530 From: "Naveen N. Rao" MIME-Version: 1.0 To: Mauro Carvalho Chehab CC: Borislav Petkov , tony.luck@intel.com, bhelgaas@google.com, rostedt@goodmis.org, rjw@sisk.pl, lance.ortiz@hp.com, linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] mce: acpi/apei: trace: Enable ghes memory error trace event References: <1375986471-27113-1-git-send-email-naveen.n.rao@linux.vnet.ibm.com> <1375986471-27113-4-git-send-email-naveen.n.rao@linux.vnet.ibm.com> <20130808163822.67e0828a@samsung.com> <20130810180322.GC4155@pd.tnic> <20130812083355.47c1bae8@samsung.com> In-Reply-To: <20130812083355.47c1bae8@samsung.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-acpi-owner@vger.kernel.org List-ID: On 08/12/2013 05:03 PM, Mauro Carvalho Chehab wrote: > Em Sat, 10 Aug 2013 20:03:22 +0200 > Borislav Petkov escreveu: > >> On Thu, Aug 08, 2013 at 04:38:22PM -0300, Mauro Carvalho Chehab wrote: >>> Em Thu, 08 Aug 2013 23:57:51 +0530 >>> "Naveen N. Rao" escreveu: >>> >>>> Enable memory error trace event in cper.c >>> >>> Why do we need to do that? Memory error events are already handled >>> via edac_ghes module, >> >> If APEI gives me all the required information in order to deal with the >> hardware error - and it looks like it does - then the additional layer >> of ghes_edac is not needed. > > APEI is just the mechanism that collects the data, not the mechanism > that reports to userspace. I think what Boris is saying is that ghes_edac isn't adding anything more here given what we get from APEI structures. So, there doesn't seem to be a need to add dependency on edac for this purpose. Further, ghes_edac seems to require EDAC_MM_EDAC to be compiled into the kernel (not a module). So, more dependencies. > > The current implementation is that APEI already reports those errors > via ghes_edac driver. It also reports the very same error via MCE > (although the APEI interface to MCE is currently broken for everything > that it is not Nehalem-EX - as it basically emulates the MCE log for > that specific architecture). So, I looked at ghes_edac and it basically seems to boil down to trace_mc_event. But, this only seems to expose the APEI data as a string and doesn't look to really make all the fields available to user-space in a raw manner. Not sure how well this can be utilised by a user-space tool. Do you have suggestions on how we can do this? Thanks, Naveen