From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DF469C433EF for ; Tue, 9 Nov 2021 21:30:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BF037610A0 for ; Tue, 9 Nov 2021 21:30:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230492AbhKIVc4 (ORCPT ); Tue, 9 Nov 2021 16:32:56 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39936 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239398AbhKIVc4 (ORCPT ); Tue, 9 Nov 2021 16:32:56 -0500 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9D66AC061764; Tue, 9 Nov 2021 13:30:09 -0800 (PST) Received: from zn.tnic (p200300ec2f18aa00aec912b1b11fde1a.dip0.t-ipconnect.de [IPv6:2003:ec:2f18:aa00:aec9:12b1:b11f:de1a]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id EE48F1EC0390; Tue, 9 Nov 2021 22:30:07 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1636493408; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=Na1GO8CHHfkH7PTogxxL39ysdX5U41PDDHRMkhNbsVk=; b=NDKwOXu5H+BVEopZN1+LF2gcd+5OR1YGOFBcHcPb6s9mu0b2s6wJm547IswbKTMjd0agCH nnP8dIu0efCcUUshzNOTmvlr9fliZVwgJ8ds1CBDkVAXU2Vb3T7SCLwG3MySfJ6P18HKhQ Z9fYWCpXrW13TCkRPuzYxl2RkTgLR0w= Date: Tue, 9 Nov 2021 22:30:01 +0100 From: Borislav Petkov To: "Luck, Tony" Cc: Zhaolong Zhang , "x86@kernel.org" , "linux-edac@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "Paul E . McKenney" Subject: Re: [PATCH] x86/mce: drop cpu_missing since we have more capable mce_missing_cpus Message-ID: References: <4d526023.3cde.17cff097bab.Coremail.zhangzl2013@126.com> <4a77f582.4434.17cff975224.Coremail.zhangzl2013@126.com> <776fad3d.3369.17d03d2c2ba.Coremail.zhangzl2013@126.com> <84e2622e4300490587793d2509f7b3ff@intel.com> <42d1d11d63f3453db61fad58a91e2ba5@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <42d1d11d63f3453db61fad58a91e2ba5@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-edac@vger.kernel.org On Tue, Nov 09, 2021 at 08:44:41PM +0000, Luck, Tony wrote: > > what do we do with the sysfs knob? It probably is an ABI: > > > > /sys/devices/system/machinecheck/machinecheck1/tolerant > > /sys/devices/system/machinecheck/machinecheck2/tolerant > > $ git grep tolerant -- Documentation/ABI/ > $ > > An undocumented ABI! Well, not documented with all the other sysfs bits. > > It does appear in: > Documentation/x86/x86_64/machinecheck.rst Yeah, we have some spreading of documentation which is not necessarily helpful. > Of course, like a lot of documentation, it isn't accurate. It wasn't > updated to describe what happens with recoverable errors. Final > paragraph says: > > Note this only makes a difference if the CPU allows recovery > from a machine check exception. Current x86 CPUs generally do > not. > > Recovery was first introduced in the Nehalem generation which > ark.intel.com says was launched in Q1'2010. So over a decade. > > Choices: 1) Leave the file there, but remove the code that uses the > value 2) Delete the file too > > Option 1 doesn't break any scripts that look for the file, but may > make people shout louder when they find it no longer does anything. > > Option 2 is the more honest approach. Ack, we can try 2 and see who cries. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette