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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 7A0BCC63798 for ; Fri, 27 Nov 2020 17:32:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3CF9220B80 for ; Fri, 27 Nov 2020 17:32:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="i8xURzJH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732271AbgK0Rc3 (ORCPT ); Fri, 27 Nov 2020 12:32:29 -0500 Received: from mail.kernel.org ([198.145.29.99]:36202 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730603AbgK0Rc3 (ORCPT ); Fri, 27 Nov 2020 12:32:29 -0500 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4844B208D5; Fri, 27 Nov 2020 17:32:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1606498348; bh=y7pZjK6D6viaEN3Bl1PpoDAzFWvUIb7VUvmvPP4NPCY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=i8xURzJHl33qK3wz6q9xrhrWQPSAYGFUkOUEIGPPLaJURDR25kipWeB0kZc5cv5F/ daWib4pMyMYB5lcQ8SiRLPLveV+wAc+SAai+jcp/WuYEEG/O97wJJfm9mkkBPBdVPF hcyedWSRvFRV3yCvYX8jPs6e70VeYwe7k/u8tYas= Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id 6A77D40D0D; Fri, 27 Nov 2020 14:32:26 -0300 (-03) Date: Fri, 27 Nov 2020 14:32:26 -0300 From: Arnaldo Carvalho de Melo To: Namhyung Kim Cc: Jiri Olsa , Ingo Molnar , Peter Zijlstra , Mark Rutland , Alexander Shishkin , LKML , Stephane Eranian , Ian Rogers , Sam Xi , Andi Kleen Subject: Re: [PATCH v2 1/2] perf stat: Use proper cpu for shadow stats Message-ID: <20201127173226.GO70905@kernel.org> References: <20201127041404.390276-1-namhyung@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201127041404.390276-1-namhyung@kernel.org> X-Url: http://acmel.wordpress.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Fri, Nov 27, 2020 at 01:14:03PM +0900, Namhyung Kim escreveu: > Currently perf stat shows some metrics (like IPC) for defined events. > But when no aggregation mode is used (-A option), it shows incorrect > values since it used a value from a different cpu. > > Before: > > $ perf stat -aA -e cycles,instructions sleep 1 > > Performance counter stats for 'system wide': > > CPU0 116,057,380 cycles > CPU1 86,084,722 cycles > CPU2 99,423,125 cycles > CPU3 98,272,994 cycles > CPU0 53,369,217 instructions # 0.46 insn per cycle > CPU1 33,378,058 instructions # 0.29 insn per cycle > CPU2 58,150,086 instructions # 0.50 insn per cycle > CPU3 40,029,703 instructions # 0.34 insn per cycle > > 1.001816971 seconds time elapsed > > So the IPC for CPU1 should be 0.38 (= 33,378,058 / 86,084,722) > but it was 0.29 (= 33,378,058 / 116,057,380) and so on. > > After: > > $ perf stat -aA -e cycles,instructions sleep 1 > > Performance counter stats for 'system wide': > > CPU0 109,621,384 cycles > CPU1 159,026,454 cycles > CPU2 99,460,366 cycles > CPU3 124,144,142 cycles > CPU0 44,396,706 instructions # 0.41 insn per cycle > CPU1 120,195,425 instructions # 0.76 insn per cycle > CPU2 44,763,978 instructions # 0.45 insn per cycle > CPU3 69,049,079 instructions # 0.56 insn per cycle > > 1.001910444 seconds time elapsed Thanks, applied, the new 'perf test' entry in 2/2 will be merged into perf/core, as it isn't purely a fix, - Arnaldo > Reported-by: Sam Xi > Fixes: 44d49a600259 ("perf stat: Support metrics in --per-core/socket mode") > Reviewed-by: Andi Kleen > Acked-by: Jiri Olsa > Signed-off-by: Namhyung Kim > --- > tools/perf/util/stat-display.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/tools/perf/util/stat-display.c b/tools/perf/util/stat-display.c > index 4b57c0c07632..a963b5b8eb72 100644 > --- a/tools/perf/util/stat-display.c > +++ b/tools/perf/util/stat-display.c > @@ -324,13 +324,10 @@ static int first_shadow_cpu(struct perf_stat_config *config, > struct evlist *evlist = evsel->evlist; > int i; > > - if (!config->aggr_get_id) > - return 0; > - > if (config->aggr_mode == AGGR_NONE) > return id; > > - if (config->aggr_mode == AGGR_GLOBAL) > + if (!config->aggr_get_id) > return 0; > > for (i = 0; i < evsel__nr_cpus(evsel); i++) { > -- > 2.29.2.454.gaff20da3a2-goog > -- - Arnaldo