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 X-Spam-Level: X-Spam-Status: No, score=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E29BBC34031 for ; Tue, 18 Feb 2020 21:54:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AFA18207FD for ; Tue, 18 Feb 2020 21:54:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="QGtWD285" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726808AbgBRVyT (ORCPT ); Tue, 18 Feb 2020 16:54:19 -0500 Received: from mail.skyhub.de ([5.9.137.197]:42678 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726482AbgBRVyT (ORCPT ); Tue, 18 Feb 2020 16:54:19 -0500 Received: from zn.tnic (p200300EC2F0C1F00B896B40159BA1A96.dip0.t-ipconnect.de [IPv6:2003:ec:2f0c:1f00:b896:b401:59ba:1a96]) (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 E0C8F1EC0C31; Tue, 18 Feb 2020 22:54:16 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1582062857; 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=zwwTIfNeXE0+PhfSG968Dl+SHEvpcxijJ0a07ILjQLw=; b=QGtWD285YbgVFOi9XzS2Uav1mmO1rv7jcv9KXSra++21FdyQVYyJLcboFb0M8IGe35XYI7 9H+SxFWLcTxBt+N4MkalKow4lNV9vIp56K10d8n6RqrvAogTfYxweMD/fot9Oa4SFicM6l l6mrEs67SdidLPEekTl7JA4BBpXBn3U= Date: Tue, 18 Feb 2020 22:54:11 +0100 From: Borislav Petkov To: Kim Phillips Cc: Peter Zijlstra , Ingo Molnar , Ingo Molnar , Alexander Shishkin , Andi Kleen , Arnaldo Carvalho de Melo , Babu Moger , Fenghua Yu , Frank van der Linden , "H . Peter Anvin" , Huang Rui , Janakarajan Natarajan , Jan Beulich , Jiaxun Yang , Jiri Olsa , Josh Poimboeuf , Linus Torvalds , Luwei Kang , Martin =?utf-8?B?TGnFoWth?= , Matt Fleming , Michael Petlan , Namhyung Kim , Paolo Bonzini , Pawan Gupta , Suravee Suthikulpanit , Thomas Gleixner , Tom Lendacky , x86@kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v3] x86/cpu/amd: Enable the fixed Instructions Retired counter IRPERF Message-ID: <20200218215411.GU14449@zn.tnic> References: <20200214201805.13830-1-kim.phillips@amd.com> <20200218112035.GB14449@zn.tnic> <15f0ff78-1a94-cfa7-297b-c226cb98d10f@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <15f0ff78-1a94-cfa7-297b-c226cb98d10f@amd.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Tue, Feb 18, 2020 at 03:35:25PM -0600, Kim Phillips wrote: > The only reason to have it show in /proc/cpuinfo is for userspace, > but they can check for a nonzero count prior to using, instead. How is userspace going to check it? perf tool or people *can* check it? If perf is going to check it then I'm fine with having the bug bit in /proc/cpuinfo along with a patch for perf adding usage for it. If not and people in userspace can maybe check it but they probably won't then adding that bug bit would be a waste of bit. > Let me know if you'd like me to send a v4, or if you will just apply > this version of yours. I can take the simpler version for now. If you still want to have perf tool check the bit, you could submit a new patch adding that bug bit along with a perf tool patch using it... -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette