From patchwork Fri Mar 8 13:22:44 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Ilpo_J=C3=A4rvinen?= X-Patchwork-Id: 778988 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.13]) (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 7B434381D4; Fri, 8 Mar 2024 13:23:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.13 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709904217; cv=none; b=uc9VaBH0kfHVJsXl0Q6uTGKX5uAUa7eVYDF5/bjV/jwlQ4Z2M0A/0XVp5agimSpnY6CpEhIxFEveXNg1EbAe0KGoLPxlBRMlQu+OGMgnMRUQ9HOFIosdk0D4wbA+/JkDqrtyg0lIa/3ndLyHJqQzrdJd375yPEj5PotDK+PbK0k= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709904217; c=relaxed/simple; bh=sEYLNbkyuSH14euw2egzBjKSQE2lGokAtrCPLRS27NE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=NPTkI1q8Avw7qgthPDHGuT2Ft8xX49XKcXR2Efl7ee1R02S7jxsqbf3aANFaT2xcBZDEnL6vTMdJxQZ1REL3L52tiQDeV0UtAzhnRRgT/AQqcd+jBuIE5lTCvQkPccTt+D2R1gewj3TXppegmSdYwFhabznJogeCye3P0MjX4iQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=JRnCwe3D; arc=none smtp.client-ip=192.198.163.13 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="JRnCwe3D" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1709904215; x=1741440215; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=sEYLNbkyuSH14euw2egzBjKSQE2lGokAtrCPLRS27NE=; b=JRnCwe3DAOCmvwqussb4Q95bDkPa3Ae+t++1BuDoqmASV2darlNkcMC0 L8F2If8Vzm3BnXokwo9MdQ3/y2ZqxYnIIuoRtPfmCGNTrGPhd9qgfwxn+ YoWikDv5Znl9RHvOQmnzT6eB+pjhWCxG7OPrR/ZwQ+flaJjeSd6jjMzDT jImONn84gY2WuWNY6t3SOOulcvlQN0TXQ5X4OvfWYETVX3ROgUcS/914Z rTScKM9n2HzpAl0VT3c82g/tPM5Le1oeQujAvd0j5DjIZ+4D5bzA5i6wW QsV4+pkG+HVCGTs7n8o8Z7V0mlkmzK+1akFAz82XJRkJu6NuJ/oBmgd86 A==; X-IronPort-AV: E=McAfee;i="6600,9927,11006"; a="7568428" X-IronPort-AV: E=Sophos;i="6.07,109,1708416000"; d="scan'208";a="7568428" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by fmvoesa107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Mar 2024 05:23:34 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,109,1708416000"; d="scan'208";a="47927962" Received: from ijarvine-desk1.ger.corp.intel.com (HELO localhost) ([10.245.244.186]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Mar 2024 05:23:31 -0800 From: =?utf-8?q?Ilpo_J=C3=A4rvinen?= To: linux-kselftest@vger.kernel.org, Reinette Chatre , Shuah Khan , Babu Moger , =?utf-8?q?Maciej_Wiecz=C3=B3r-Retman?= , Fenghua Yu , linux-kernel@vger.kernel.org Cc: =?utf-8?q?Ilpo_J=C3=A4rvinen?= Subject: [PATCH 02/13] selftests/resctrl: Calculate resctrl FS derived mem bw over sleep(1) only Date: Fri, 8 Mar 2024 15:22:44 +0200 Message-Id: <20240308132255.14442-3-ilpo.jarvinen@linux.intel.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240308132255.14442-1-ilpo.jarvinen@linux.intel.com> References: <20240308132255.14442-1-ilpo.jarvinen@linux.intel.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 For MBM/MBA tests, measure_vals() calls get_mem_bw_imc() that performs the measurement over a duration of sleep(1) call. The memory bandwidth numbers from IMC are derived over this duration. The resctrl FS derived memory bandwidth, however, is calculated inside measure_vals() and only takes delta between the previous value and the current one which besides the actual test, also samples inter-test noise. Rework the logic in measure_vals() and get_mem_bw_imc() such that the resctrl FS memory bandwidth section covers much shorter duration closely matching that of the IMC perf counters to improve measurement accuracy. Suggested-by: Reinette Chatre Signed-off-by: Ilpo Järvinen --- tools/testing/selftests/resctrl/resctrl_val.c | 72 +++++++++++++------ 1 file changed, 50 insertions(+), 22 deletions(-) diff --git a/tools/testing/selftests/resctrl/resctrl_val.c b/tools/testing/selftests/resctrl/resctrl_val.c index 36139cba7be8..4df2cd738f88 100644 --- a/tools/testing/selftests/resctrl/resctrl_val.c +++ b/tools/testing/selftests/resctrl/resctrl_val.c @@ -293,28 +293,35 @@ static int initialize_mem_bw_imc(void) } /* - * get_mem_bw_imc: Memory band width as reported by iMC counters + * perf_open_imc_mem_bw - Open perf fds for IMCs * @cpu_no: CPU number that the benchmark PID is binded to - * @bw_report: Bandwidth report type (reads, writes) - * - * Memory B/W utilized by a process on a socket can be calculated using - * iMC counters. Perf events are used to read these counters. - * - * Return: = 0 on success. < 0 on failure. */ -static int get_mem_bw_imc(int cpu_no, char *bw_report, float *bw_imc) +static int perf_open_imc_mem_bw(int cpu_no) { - float reads, writes, of_mul_read, of_mul_write; int imc, j, ret; - /* Start all iMC counters to log values (both read and write) */ - reads = 0, writes = 0, of_mul_read = 1, of_mul_write = 1; for (imc = 0; imc < imcs; imc++) { for (j = 0; j < 2; j++) { ret = open_perf_event(imc, cpu_no, j); if (ret) return -1; } + } + + return 0; +} + +/* + * do_mem_bw_test - Perform memory bandwidth test + * + * Runs memory bandwidth test over one second period. Also, handles starting + * and stopping of the IMC perf counters around the test. + */ +static void do_imc_mem_bw_test(void) +{ + int imc, j; + + for (imc = 0; imc < imcs; imc++) { for (j = 0; j < 2; j++) membw_ioctl_perf_event_ioc_reset_enable(imc, j); } @@ -326,6 +333,24 @@ static int get_mem_bw_imc(int cpu_no, char *bw_report, float *bw_imc) for (j = 0; j < 2; j++) membw_ioctl_perf_event_ioc_disable(imc, j); } +} + +/* + * get_mem_bw_imc - Memory band width as reported by iMC counters + * @bw_report: Bandwidth report type (reads, writes) + * + * Memory B/W utilized by a process on a socket can be calculated using + * iMC counters. Perf events are used to read these counters. + * + * Return: = 0 on success. < 0 on failure. + */ +static int get_mem_bw_imc(char *bw_report, float *bw_imc) +{ + float reads, writes, of_mul_read, of_mul_write; + int imc, j; + + /* Start all iMC counters to log values (both read and write) */ + reads = 0, writes = 0, of_mul_read = 1, of_mul_write = 1; /* * Get results which are stored in struct type imc_counter_config @@ -593,10 +618,9 @@ static void initialize_llc_occu_resctrl(const char *ctrlgrp, const char *mongrp, } static int measure_vals(const struct user_params *uparams, - struct resctrl_val_param *param, - unsigned long *bw_resc_start) + struct resctrl_val_param *param) { - unsigned long bw_resc, bw_resc_end; + unsigned long bw_resc, bw_resc_start, bw_resc_end; float bw_imc; int ret; @@ -607,22 +631,27 @@ static int measure_vals(const struct user_params *uparams, * Compare the two values to validate resctrl value. * It takes 1sec to measure the data. */ - ret = get_mem_bw_imc(uparams->cpu, param->bw_report, &bw_imc); + ret = perf_open_imc_mem_bw(uparams->cpu); if (ret < 0) return ret; + ret = get_mem_bw_resctrl(&bw_resc_start); + if (ret < 0) + return ret; + + do_imc_mem_bw_test(); + ret = get_mem_bw_resctrl(&bw_resc_end); if (ret < 0) return ret; - bw_resc = (bw_resc_end - *bw_resc_start) / MB; - ret = print_results_bw(param->filename, bm_pid, bw_imc, bw_resc); - if (ret) + ret = get_mem_bw_imc(param->bw_report, &bw_imc); + if (ret < 0) return ret; - *bw_resc_start = bw_resc_end; + bw_resc = (bw_resc_end - bw_resc_start) / MB; - return 0; + return print_results_bw(param->filename, bm_pid, bw_imc, bw_resc); } /* @@ -696,7 +725,6 @@ int resctrl_val(const struct resctrl_test *test, struct resctrl_val_param *param) { char *resctrl_val = param->resctrl_val; - unsigned long bw_resc_start = 0; struct sigaction sigact; int ret = 0, pipefd[2]; char pipe_message = 0; @@ -838,7 +866,7 @@ int resctrl_val(const struct resctrl_test *test, if (!strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR)) || !strncmp(resctrl_val, MBA_STR, sizeof(MBA_STR))) { - ret = measure_vals(uparams, param, &bw_resc_start); + ret = measure_vals(uparams, param); if (ret) break; } else if (!strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR))) {