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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1C754C433EF for ; Mon, 10 Jan 2022 19:26:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243289AbiAJT0i (ORCPT ); Mon, 10 Jan 2022 14:26:38 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:39228 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241847AbiAJT0c (ORCPT ); Mon, 10 Jan 2022 14:26:32 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 246E0B817D4; Mon, 10 Jan 2022 19:26:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 20A53C36AE9; Mon, 10 Jan 2022 19:26:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1641842789; bh=tQUDkCICKljQOn/1ICNiOjXp97jhIjg9mBvFnFfvjTw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mAh8fp/eOpsvvtpEcRSotyG6IrBpsE8dCNR8F34FVa0tO/QopHjYD2MR6sISvpLzS 3zhnlt2QnZav2gm4NhlMRA2HcaMKJxRqynn23MNxvLvpv/2KaCJx6asgfualJmRNhk DWi+07sYd8BnztoMXOMa0IThvfn91mB6yAq6/bKdxfL4eYUASafJOvZ2UJhSKlZPhb i4kL9fmfIlfhBmKdRIxuV2fuwx/fyETj6UgoVZQx0xU0nzVogEaoDq3aE/+TwVKkXn 0Y/mQdoJgqtfVt9xzOXQHt1yTT/3C1Vw+mw8Tauh5U1Rqx4BfU7mL58n2i7hQb18U/ TyvFQU7Oc7KwQ== Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id 92D8B40B92; Mon, 10 Jan 2022 16:26:26 -0300 (-03) Date: Mon, 10 Jan 2022 16:26:26 -0300 From: Arnaldo Carvalho de Melo To: Ian Rogers Cc: Andi Kleen , Jiri Olsa , Namhyung Kim , John Garry , Kajol Jain , "Paul A . Clarke" , Riccardo Mancini , Kan Liang , Peter Zijlstra , Ingo Molnar , Mark Rutland , Alexander Shishkin , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, Vineet Singh , James Clark , Mathieu Poirier , Suzuki K Poulose , Mike Leach , Leo Yan , coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, zhengjun.xing@intel.com, eranian@google.com Subject: Re: [PATCH v4 44/48] perf bpf: Rename cpu to cpu_map_idx Message-ID: References: <20220105061351.120843-1-irogers@google.com> <20220105061351.120843-45-irogers@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Url: http://acmel.wordpress.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Mon, Jan 10, 2022 at 04:10:46PM -0300, Arnaldo Carvalho de Melo escreveu: > Em Tue, Jan 04, 2022 at 10:13:47PM -0800, Ian Rogers escreveu: > > Synchronize the caller in evsel with the called function. > > Shorten 3 lines of code in bperf_read by using > > perf_cpu_map__for_each_cpu. > > This code is frequently using variables named cpu as cpu map indices, > > which doesn't matter as all CPUs are in the CPU map. It is strange in > > some cases the cpumap is used at all. > > CC /tmp/build/perf/builtin-stat.o > INSTALL trace_plugins > CC /tmp/build/perf/util/evlist.o > CC /tmp/build/perf/util/evsel.o > CC /tmp/build/perf/util/header.o > CC /tmp/build/perf/util/bpf_counter.o > CC /tmp/build/perf/util/bpf_counter_cgroup.o > CC /tmp/build/perf/util/bpf_ftrace.o > In file included from util/cpumap.h:8, > from util/bpf_counter.c:23: > util/bpf_counter.c: In function ‘bperf__read’: > /var/home/acme/git/perf/tools/lib/perf/include/perf/cpumap.h:27:20: error: comparison of integer expressions of different signedness: ‘__u32’ {aka ‘unsigned int’} and ‘int’ [-Werror=sign-compare] > 27 | (idx) < perf_cpu_map__nr(cpus); \ > | ^ > util/bpf_counter.c:626:25: note: in expansion of macro ‘perf_cpu_map__for_each_cpu’ > 626 | perf_cpu_map__for_each_cpu(cpu, j, all_cpu_map) { > | ^~~~~~~~~~~~~~~~~~~~~~~~~~ > util/bpf_counter.c:611:21: error: unused variable ‘num_cpu’ [-Werror=unused-variable] > 611 | __u32 i, j, num_cpu; > | ^~~~~~~ > cc1: all warnings being treated as errors > make[4]: *** [/var/home/acme/git/perf/tools/build/Makefile.build:96: /tmp/build/perf/util/bpf_counter.o] Error 1 > make[4]: *** Waiting for unfinished jobs.... > make[3]: *** [/var/home/acme/git/perf/tools/build/Makefile.build:139: util] Error 2 > make[2]: *** [Makefile.perf:665: /tmp/build/perf/perf-in.o] Error 2 > make[1]: *** [Makefile.perf:240: sub-make] Error 2 > make: *** [Makefile:113: install-bin] Error 2 > make: Leaving directory '/var/home/acme/git/perf/tools/perf' > > Performance counter stats for 'make -k BUILD_BPF_SKEL=1 CORESIGHT=1 PYTHON=python3 O=/tmp/build/perf -C tools/perf install-bin': > > 15,589,752,360 cycles:u > 28,227,862,710 instructions:u # 1.81 insn per cycle > > 1.996638375 seconds time elapsed > > 3.567457000 seconds user > 0.934840000 seconds sys > > > ⬢[acme@toolbox perf]$ git log --oneline -1 > 0083ba4c6a931fd0 (HEAD) perf bpf: Rename cpu to cpu_map_idx > ⬢[acme@toolbox perf]$ > > Trying to fix... Would be better to have the "Shorten 3 lines of code in bperf_read by using perf_cpu_map__for_each_cpu." in a separate patch, try to do this next time. Below cures the two issues. - Arnaldo Committer notes: Found when building with BUILD_BPF_SKEL=1: Remove unused 'num_cpu' variable in bperf__read(). Make 'j' an 'int' as it is used in perf_cpu_map__for_each_cpu() to compare against an 'int' diff --git a/tools/perf/util/bpf_counter.c b/tools/perf/util/bpf_counter.c index ae5bd87ff02033c2..80d1a3a31052fe55 100644 --- a/tools/perf/util/bpf_counter.c +++ b/tools/perf/util/bpf_counter.c @@ -608,7 +608,8 @@ static int bperf__read(struct evsel *evsel) __u32 num_cpu_bpf = cpu__max_cpu(); struct bpf_perf_event_value values[num_cpu_bpf]; int reading_map_fd, err = 0; - __u32 i, j, num_cpu; + __u32 i; + int j; bperf_sync_counters(evsel); reading_map_fd = bpf_map__fd(skel->maps.accum_readings);