From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mauro Carvalho Chehab Subject: Re: [PATCH 3/3] mce: acpi/apei: trace: Enable ghes memory error trace event Date: Mon, 12 Aug 2013 11:49:32 -0300 Message-ID: <20130812114932.52bb0314@samsung.com> 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> <20130812123813.GD18018@pd.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from mailout1.w2.samsung.com ([211.189.100.11]:10388 "EHLO usmailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755720Ab3HLOtl (ORCPT ); Mon, 12 Aug 2013 10:49:41 -0400 In-reply-to: <20130812123813.GD18018@pd.tnic> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Borislav Petkov Cc: "Naveen N. Rao" , 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 Em Mon, 12 Aug 2013 14:38:13 +0200 Borislav Petkov escreveu: > On Mon, Aug 12, 2013 at 08:33:55AM -0300, Mauro Carvalho Chehab wrote: > > APEI is just the mechanism that collects the data, not the mechanism > > that reports to userspace. > > Both methods add a tracepoint - no difference. > > > I really don't see any sense on adding yet-another-way to report the > > very same error. > > Well, your suggested way through the layers is this: > > Hardware->APEI->EDAC. > > His is > > Hardware->APEI. > > If I can lose the EDAC layer, then this is a clear win. Clear win from what PoV? Userspace will need to decode a different type of tracing, and implement a different logic for APEI. So, it will be reinventing the wheel, with a different trace format, and will require userspace to implement another tracing event for the same thing that EDAC already provides. Also, if both ghes_edac and this new tracing is enabled, userspace will receive twice the same event, as two traces will be received for the same thing. Worse than that, how userspace is supposed to merge those two events into one? > -- Cheers, Mauro