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=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 26530C4360F for ; Tue, 2 Apr 2019 15:09:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E83B52082C for ; Tue, 2 Apr 2019 15:09:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="rE/O3t6k" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731315AbfDBPJl (ORCPT ); Tue, 2 Apr 2019 11:09:41 -0400 Received: from mail-lj1-f194.google.com ([209.85.208.194]:40276 "EHLO mail-lj1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730616AbfDBPJl (ORCPT ); Tue, 2 Apr 2019 11:09:41 -0400 Received: by mail-lj1-f194.google.com with SMTP id q66so11920191ljq.7 for ; Tue, 02 Apr 2019 08:09:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=Z0pplf97Qa0x1rfBTzORlWE9huCotnwaWGrQII1utZo=; b=rE/O3t6kk/QZPxvR2GzRLQD302tFR94BdOxcFNt9+9xXwn8mC/PQVR5fMtUVd+PKTV V7gfrBiOYdTFhfs97HJfwGlwIrE7reerUu3s4GZ4UPkB+IAri7fMYiCT40zkXaQPRTPj tQIf5e9r6Sx+I65f1HDO8pFsEznZjWMDu5wbRoBB4q+BjLIK5Mr9W4ld6ouveTkAh6d7 4Dfit8dyteqL/tI7Kto6GyNkoOzR+r9BMKYktmXQZyxqBeSy6vRGBw+G1RLdyZi0/0fA srarGE9Ws27HXnggdiE2ORG6FW5avTHszk98JHORXreyKbJ2cZdFF+/6Lgckp8Nf5n6d +HuQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=Z0pplf97Qa0x1rfBTzORlWE9huCotnwaWGrQII1utZo=; b=ON8zfNZv/FnMQKju1id9F//xjYrzaZzwoOF0XNds3v9E/9cJZUXG+/rpCO47gg1eG7 6T4dW+UFoRpiqJAWD0e18b57wEhKcPaDpwqCtu2/HXQ+U8/3FKqkCC/91hO7ajhIpDY2 pa7W0Rb52TYukFf+wuTDK/xxekrj0/5GaC0ENx6ogC9jv5sH8bTh+jZCCjAaO3QMDL7z lqJ1IgxjwhK0NiSi0c2a7ruYdam6p1dhbtfbeLH1ZxRb2GiaCzG8UwLfIXhmu1jWj3LU ae71QfXwbayC4fYWz7a/rVORKRCjqYkdJJS3YhRo8p3eXbfTxatLP0uogdABhpPtnXre ZOzg== X-Gm-Message-State: APjAAAXQozn+GUZablfKfhTxabXQZI8PUQ/qMfCUb+udrtystD8daTW9 7FK8UIE+IXh4ZI5QGs83qTQ= X-Google-Smtp-Source: APXvYqxlwltxLwsMB57nBq3BAq/8ihS7+yBVpsGSWmDe/waZJ8o+BUqpg/7P5oDdo1FmlQz7VWEEbg== X-Received: by 2002:a2e:9812:: with SMTP id a18mr34388969ljj.146.1554217779060; Tue, 02 Apr 2019 08:09:39 -0700 (PDT) Received: from uranus.localdomain ([5.18.103.226]) by smtp.gmail.com with ESMTPSA id f25sm2505744lfc.46.2019.04.02.08.09.38 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 02 Apr 2019 08:09:38 -0700 (PDT) Received: by uranus.localdomain (Postfix, from userid 1000) id 7C95A4601CA; Tue, 2 Apr 2019 18:09:36 +0300 (MSK) Date: Tue, 2 Apr 2019 18:09:36 +0300 From: Cyrill Gorcunov To: Vince Weaver Cc: Peter Zijlstra , "Lendacky, Thomas" , "x86@kernel.org" , "linux-kernel@vger.kernel.org" , Arnaldo Carvalho de Melo , Alexander Shishkin , Ingo Molnar , Borislav Petkov , Namhyung Kim , Thomas Gleixner , Jiri Olsa , Stephane Eranian Subject: Re: [RFC PATCH v3 0/3] x86/perf/amd: AMD PMC counters and NMI latency Message-ID: <20190402150936.GB23501@uranus> References: <155415519143.24457.2706922532995302758.stgit@tlendack-t1.amdoffice.net> <20190402130302.GL12232@hirez.programming.kicks-ass.net> <20190402132200.GA23501@uranus> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.3 (2019-02-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 02, 2019 at 10:53:38AM -0400, Vince Weaver wrote: > On Tue, 2 Apr 2019, Cyrill Gorcunov wrote: > > On Tue, Apr 02, 2019 at 03:03:02PM +0200, Peter Zijlstra wrote: > > > I have vague memories of the P4 thing crashing with Vince's perf_fuzzer, > > > but maybe I'm wrong. > > > > No, you're correct. p4 was crashing many times before we manage to make > > it more-less stable. The main problem though that to find working p4 box > > is really a problem. > > I do have some a functioning p4 system I can test on. > I can easily run the fuzzer and report crashes, but I only have limited > time/skills to actually fix the problems it turns up. You know, running fuzzer on p4 might worth in anycase. As to potential problems to fix -- i could try find some time slot for, still quite limited too 'cause of many other duties :( > One nice thing is that as of Linux 5.0 *finally* the fuzzer can run > indefinitely on most modern Intel chips without crashing (still triggers a > few warnings). So finally we have the ability to tell when a new crash is > a regression and potentially can bisect it. Although obviously this > doesn't necessarily apply to the p4. > > I do think the number of people trying to run perf on a p4 is probably > pretty small these days. Quite agree. Moreover current p4 perf code doesn't cover all potential functionality (for example cascaded counters) and nobody ever complained about it, I think exactly because not that many p4 boxes left and putting efforts into this perf module development doesn't look like a good investment, better to stick with more modern cpus and deprecate p4 with small steps.