From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S940798AbdAFWpE (ORCPT ); Fri, 6 Jan 2017 17:45:04 -0500 Received: from mga02.intel.com ([134.134.136.20]:10282 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1033542AbdAFV4x (ORCPT ); Fri, 6 Jan 2017 16:56:53 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.33,326,1477983600"; d="scan'208";a="210509142" From: Vikas Shivappa To: vikas.shivappa@intel.com, vikas.shivappa@linux.intel.com Cc: linux-kernel@vger.kernel.org, x86@kernel.org, hpa@zytor.com, tglx@linutronix.de, mingo@kernel.org, peterz@infradead.org, ravi.v.shankar@intel.com, tony.luck@intel.com, fenghua.yu@intel.com, andi.kleen@intel.com, h.peter.anvin@intel.com Subject: [PATCH 01/12] Documentation, x86/cqm: Intel Resource Monitoring Documentation Date: Fri, 6 Jan 2017 13:56:43 -0800 Message-Id: <1483739814-23000-2-git-send-email-vikas.shivappa@linux.intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1483739814-23000-1-git-send-email-vikas.shivappa@linux.intel.com> References: <1483739814-23000-1-git-send-email-vikas.shivappa@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add documentation of usage of cqm and mbm events using perf interface and examples. Signed-off-by: Vikas Shivappa --- Documentation/x86/intel_rdt_mon_ui.txt | 62 ++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100644 Documentation/x86/intel_rdt_mon_ui.txt diff --git a/Documentation/x86/intel_rdt_mon_ui.txt b/Documentation/x86/intel_rdt_mon_ui.txt new file mode 100644 index 0000000..881fa58 --- /dev/null +++ b/Documentation/x86/intel_rdt_mon_ui.txt @@ -0,0 +1,62 @@ +User Interface for Resource Monitoring in Intel Resource Director Technology + +Vikas Shivappa +David Carrillo-Cisneros +Stephane Eranian + +This feature is enabled by the CONFIG_INTEL_RDT_M Kconfig and the +X86 /proc/cpuinfo flag bits cqm_llc cqm_occup_llc cqm_mbm_total cqm_mbm_local + +Resource Monitoring +------------------- +Resource Monitoring includes cqm(cache quality monitoring) and +mbm(memory bandwidth monitoring) and uses the perf interface. A light +weight interface to enable monitoring without perf is enabled as well. + +CQM provides OS/VMM a way to monitor llc occupancy. It measures the +amount of L3 cache fills per task or cgroup. + +MBM provides OS/VMM a way to monitor bandwidth from one level of cache +to another. The current patches support L3 external bandwidth +monitoring. It supports both 'local bandwidth' and 'total bandwidth' +monitoring for the socket. Local bandwidth measures the amount of data +sent through the memory controller on the socket and total b/w measures +the total system bandwidth. + +To check the monitoring events enabled: + +$ ./tools/perf/perf list | grep -i cqm +intel_cqm/llc_occupancy/ [Kernel PMU event] +intel_cqm/local_bytes/ [Kernel PMU event] +intel_cqm/total_bytes/ [Kernel PMU event] + +Monitoring tasks and cgroups using perf +--------------------------------------- +Monitoring tasks and cgroup is like using any other perf event. + +$perf stat -I 1000 -e intel_cqm_llc/local_bytes/ -p PID1 + +This will monitor the local_bytes event of the PID1 and report once +every 1000ms + +$mkdir /sys/fs/cgroup/perf_event/p1 +$echo PID1 > /sys/fs/cgroup/perf_event/p1/tasks +$echo PID2 > /sys/fs/cgroup/perf_event/p1/tasks + +$perf stat -I 1000 -e intel_cqm_llc/llc_occupancy/ -a -G p1 + +This will monitor the llc_occupancy event of the perf cgroup p1 in +interval mode. + +Hierarchical monitoring should work just like other events and users can +also monitor a task with in a cgroup and the cgroup together, or +different cgroups in the same hierarchy can be monitored together. + +The events are associated with RMIDs and are grouped when optimal. The +RMIDs are limited hardware resources and if runout the events would just +throw error on read. + +To obtain per package data for cgroups(package x) provide any cpu in the +package as input to -C: + +$perf stat -I 1000 -e intel_cqm_llc/llc_occupancy/ -C -G p1 -- 1.9.1