From patchwork Fri Oct 18 02:33:21 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Reinette Chatre X-Patchwork-Id: 13841007 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.7]) (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 DE95B17CA0B; Fri, 18 Oct 2024 02:22:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729218163; cv=none; b=ZGv0gTGDdScfbP2MIc/GkYMPY3paKCSbhgilbqICcOd4aLU5w6hyLKIFSmffKd5Ooj0j81MgqqTvlUbCvTLwjI+7aIQ6dPiiwfFbX/E3rtlj8v65RtDNCPDWBmpPSSt7KTn1YgoD/cHOjJLA4UWG3zrrk8oAsF5ZaRFKXcGn6RY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729218163; c=relaxed/simple; bh=WDQXKvgThl+Gw40TkwesnKGx7YMUmY4xzJANs5XXJ0E=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=uDjZkIecQDuboti9xeOMZ97JlxD2m8kE8OYCGzXYo7WHNHuyuS/4MOYpdynCaNpPCOmr6sO66EO2GlQuDC7NG0m7ZxupliTnLX8epVKiRRNGX+sjWTPF38yzyy58a5CYbUU7FnLtv5izoYBxBwsJjeGRQ284j/wTa/GVWiWg3so= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=j2lUcBeA; arc=none smtp.client-ip=192.198.163.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="j2lUcBeA" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1729218162; x=1760754162; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=WDQXKvgThl+Gw40TkwesnKGx7YMUmY4xzJANs5XXJ0E=; b=j2lUcBeA0kjyQhrny+hu40422qCQ/xsm/+7ZxB9UH/K0PYBp5ZAH3PSP b/eBkkYdbMOfYmV5fLlklQjfV4w6xYzoGjUwajwfgwpaVCKh67h9oqNZx +br8AnMs6JW6Eg+uuaDRUZQKP1FL336PlWcfrgR/5HtAaLbGlFjzXDXhO g0ug6wA0QWWD7HvVQkIdkGI16daN2cnWiX27j54N3tLswwrplR3UfL7kC IJiYlSDqibioHvXvqBBYTvj50CJnkuuz+qnPzMGWDwvq3FioBNp1KQTM2 zppVF2IfnMODaSFtO7jjXb0fo6u/4JNowPXB05LfbiSvZTabkyjKxYAVc Q==; X-CSE-ConnectionGUID: lR8yhIxITiW47EcLL7SdEQ== X-CSE-MsgGUID: UmLADvKLSHOlVlIwRyN8fg== X-IronPort-AV: E=McAfee;i="6700,10204,11228"; a="54149696" X-IronPort-AV: E=Sophos;i="6.11,212,1725346800"; d="scan'208";a="54149696" Received: from orviesa010.jf.intel.com ([10.64.159.150]) by fmvoesa101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Oct 2024 19:22:37 -0700 X-CSE-ConnectionGUID: iydpUy+uQjeT0BT1/sSs/g== X-CSE-MsgGUID: 3gWlkkdPTkKqew8URjcQxw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.11,212,1725346800"; d="scan'208";a="78697714" Received: from rchatre-desk1.jf.intel.com ([10.165.154.99]) by orviesa010-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Oct 2024 19:22:36 -0700 From: Reinette Chatre To: fenghua.yu@intel.com, shuah@kernel.org, tony.luck@intel.com, peternewman@google.com, babu.moger@amd.com, ilpo.jarvinen@linux.intel.com Cc: maciej.wieczor-retman@intel.com, reinette.chatre@intel.com, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH V3 06/15] selftests/resctrl: Make wraparound handling obvious Date: Thu, 17 Oct 2024 19:33:21 -0700 Message-ID: <46b9094f4ecd8188b559bdd4146aa365b13799b9.1729218182.git.reinette.chatre@intel.com> X-Mailer: git-send-email 2.46.2 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Within mba_setup() the programmed bandwidth delay value starts at the maximum (100, or rather ALLOCATION_MAX) and progresses towards ALLOCATION_MIN by decrementing with ALLOCATION_STEP. The programmed bandwidth delay should never be negative, so representing it with an unsigned int is most appropriate. This may introduce confusion because of the "allocation > ALLOCATION_MAX" check used to check wraparound of the subtraction. Modify the mba_setup() flow to start at the minimum, ALLOCATION_MIN, and incrementally, with ALLOCATION_STEP steps, adjust the bandwidth delay value. This avoids wraparound while making the purpose of "allocation > ALLOCATION_MAX" clear and eliminates the need for the "allocation < ALLOCATION_MIN" check. Reported-by: Ilpo Järvinen Closes: https://lore.kernel.org/lkml/1903ac13-5c9c-ef8d-78e0-417ac34a971b@linux.intel.com/ Signed-off-by: Reinette Chatre Reviewed-by: Ilpo Järvinen --- Changes since V1: - New patch - Add Ilpo's Reviewed-by tag. --- tools/testing/selftests/resctrl/mba_test.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/resctrl/mba_test.c b/tools/testing/selftests/resctrl/mba_test.c index ab8496a4925b..da40a8ed4413 100644 --- a/tools/testing/selftests/resctrl/mba_test.c +++ b/tools/testing/selftests/resctrl/mba_test.c @@ -39,7 +39,8 @@ static int mba_setup(const struct resctrl_test *test, const struct user_params *uparams, struct resctrl_val_param *p) { - static int runs_per_allocation, allocation = 100; + static unsigned int allocation = ALLOCATION_MIN; + static int runs_per_allocation; char allocation_str[64]; int ret; @@ -50,7 +51,7 @@ static int mba_setup(const struct resctrl_test *test, if (runs_per_allocation++ != 0) return 0; - if (allocation < ALLOCATION_MIN || allocation > ALLOCATION_MAX) + if (allocation > ALLOCATION_MAX) return END_OF_TESTS; sprintf(allocation_str, "%d", allocation); @@ -59,7 +60,7 @@ static int mba_setup(const struct resctrl_test *test, if (ret < 0) return ret; - allocation -= ALLOCATION_STEP; + allocation += ALLOCATION_STEP; return 0; } @@ -72,8 +73,9 @@ static int mba_measure(const struct user_params *uparams, static bool show_mba_info(unsigned long *bw_imc, unsigned long *bw_resc) { - int allocation, runs; + unsigned int allocation; bool ret = false; + int runs; ksft_print_msg("Results are displayed in (MB)\n"); /* Memory bandwidth from 100% down to 10% */ @@ -103,7 +105,7 @@ static bool show_mba_info(unsigned long *bw_imc, unsigned long *bw_resc) avg_diff_per > MAX_DIFF_PERCENT ? "Fail:" : "Pass:", MAX_DIFF_PERCENT, - ALLOCATION_MAX - ALLOCATION_STEP * allocation); + ALLOCATION_MIN + ALLOCATION_STEP * allocation); ksft_print_msg("avg_diff_per: %d%%\n", avg_diff_per); ksft_print_msg("avg_bw_imc: %lu\n", avg_bw_imc);