From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 141C9381AD for ; Mon, 16 Oct 2023 20:35:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="BdYuJjt1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4DB7DC433C7; Mon, 16 Oct 2023 20:35:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1697488502; bh=wGAWECJL1BSXHvDFaMRrPSWSvwLJYHm/I9oGrujUIAg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=BdYuJjt1GSddf/zrQSv0pdrIjA45COUidcM3VPniZAQYxH6XC0ZG9D6vybAA2cQup 52zTEMSK+XeARFKnvYMKoMgdyPQTIjKPZ/12kF2cXBG5DuAak0F/G3nR8qWJMBurxg sTl/k9XqmiNvsIVp3/SNK3ovp9J6mGzclimZPtps3yDU8qNdTM9ee0c9a7o62n6SUq tVF4akZRpQnRyCytZI/B238907lNT3PSowAQ3swgFY3KtiQEEI1+Dr5pe0snxJkHLH j8sU7x7O80bIuhLDA9OFTmBGYrDN9UrnzgDZGk8iXbS1gMDXu/uTvIAf4W8/4S7UEX qKZOAANLT63mA== Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id 89DE040016; Mon, 16 Oct 2023 17:34:59 -0300 (-03) Date: Mon, 16 Oct 2023 17:34:59 -0300 From: Arnaldo Carvalho de Melo To: Namhyung Kim Cc: Ingo Molnar , Jiri Olsa , Ian Rogers , Adrian Hunter , Peter Zijlstra , LKML , linux-perf-users@vger.kernel.org Subject: Re: [PATCH v3] perf bench sched pipe: Add -G/--cgroups option Message-ID: References: <20231016044225.1125674-1-namhyung@kernel.org> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Url: http://acmel.wordpress.com Em Mon, Oct 16, 2023 at 12:55:33PM -0300, Arnaldo Carvalho de Melo escreveu: > Em Mon, Oct 16, 2023 at 12:51:52PM -0300, Arnaldo Carvalho de Melo escreveu: > > Now back at testing with with cgroups. > Humm, even without the -G I get: > [root@five ~]# perf stat -e context-switches,cgroup-switches perf bench sched pipe -l 10000 > # Running 'sched/pipe' benchmark: > # Executed 10000 pipe operations between two processes > Total time: 0.082 [sec] > 8.246400 usecs/op > 121265 ops/sec > Performance counter stats for 'perf bench sched pipe -l 10000': > 20,002 context-switches > 20,002 cgroup-switches Same number, but then I forgot to add the 'taskset -c 0' part of the command line, if I have it: [root@five ~]# perf stat -e context-switches,cgroup-switches taskset -c 0 perf bench sched pipe -l 10000 # Running 'sched/pipe' benchmark: # Executed 10000 pipe operations between two processes Total time: 0.072 [sec] 7.231500 usecs/op 138283 ops/sec Performance counter stats for 'taskset -c 0 perf bench sched pipe -l 10000': 20,002 context-switches 3 cgroup-switches 0.082855113 seconds time elapsed 0.007765000 seconds user 0.074020000 seconds sys [root@five ~]# perf stat -e context-switches,cgroup-switches taskset -c 0 perf bench sched pipe -l 10000 -G AAA,BBB # Running 'sched/pipe' benchmark: # Executed 10000 pipe operations between two processes Total time: 0.093 [sec] 9.341800 usecs/op 107045 ops/sec Performance counter stats for 'taskset -c 0 perf bench sched pipe -l 10000 -G AAA,BBB': 20,004 context-switches 20,003 cgroup-switches 0.103436330 seconds time elapsed 0.018109000 seconds user 0.063058000 seconds sys [root@five ~]# I.e. it works as in your results, but can you please spell out why that 'taskset -c 0' is needed to get these results? I wasn't expecting the same number of cgroup-switches when not using 'taskset -c 0' :-\ - Arnaldo