Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933740AbbBISAk (ORCPT ); Mon, 9 Feb 2015 13:00:40 -0500 Received: from mga11.intel.com ([192.55.52.93]:6586 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933404AbbBISAg (ORCPT ); Mon, 9 Feb 2015 13:00:36 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.09,545,1418112000"; d="scan'208";a="683211800" From: Tony Luck In-Reply-To: <20150209110149.GC4051@pd.tnic> Subject: [PATCHv3] x86/mce: Fix regression. All error records should report via /dev/mcelog To: Ingo Molnar Cc: x86@kernel.org, linux-kernel@vger.kernel.org, linux-edac@kernel.org Date: Mon, 09 Feb 2015 10:00:19 -0800 Message-Id: <54d8f5b3325925e60b@agluck-desk.sc.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2220 Lines: 61 I'm getting complaints from validation teams that have updated their Linux kernels from ancient versions to current. They don't see the error logs they expect. I tell the to unload any EDAC drivers[1], and things start working again. The problem is that we short-circuit the logging process if any function on the decoder chain claims to have dealt with the problem: ret = atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, m); if (ret == NOTIFY_STOP) return; The logic we used when we added this code was that we did not want to confuse users with double reports of the same error. But it turns out users are not confused - they are upset that they don't see a log where their tools used to find a log. I could also get into a long description of how the consumer of this log does more than just decode model specific details of the error. It keeps counts, tracks thresholds, takes actions and runs scripts that can alert administrators to problems. [1] We've recently compounded the problem because the acpi_extlog driver also registers for this notifier and also returns NOTIFY_STOP. Signed-off-by: Tony Luck --- v3: Drop v2 changes that included a vendor specific check. Go back to v1. New commit message that better describes the problem. arch/x86/kernel/cpu/mcheck/mce.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index d2c611699cd9..f439c429c133 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -150,14 +150,11 @@ static struct mce_log mcelog = { void mce_log(struct mce *mce) { unsigned next, entry; - int ret = 0; /* Emit the trace record: */ trace_mce_record(mce); - ret = atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, mce); - if (ret == NOTIFY_STOP) - return; + atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, mce); mce->finished = 0; wmb(); -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/