From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932377Ab0EKJll (ORCPT ); Tue, 11 May 2010 05:41:41 -0400 Received: from mga01.intel.com ([192.55.52.88]:60385 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755714Ab0EKJlk (ORCPT ); Tue, 11 May 2010 05:41:40 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.53,206,1272870000"; d="scan'208";a="566051605" Subject: Re: [RFC][PATCH 3/9] perf: export registerred pmus via sysfs From: Lin Ming To: Peter Zijlstra Cc: Ingo Molnar , Corey Ashford , Frederic Weisbecker , "eranian@gmail.com" , "Gary.Mohr@Bull.com" , "arjan@linux.intel.com" , "Zhang, Yanmin" , Paul Mackerras , "David S. Miller" , Russell King , Paul Mundt , lkml , Arnaldo Carvalho de Melo , Will Deacon , Maynard Johnson , Carl Love In-Reply-To: <1273569154.5605.3499.camel@twins> References: <1273484401.5605.3333.camel@twins> <1273486313.15998.76.camel@minggr.sh.intel.com> <1273486708.5605.3342.camel@twins> <1273487195.15998.85.camel@minggr.sh.intel.com> <1273490824.5605.3379.camel@twins> <20100510114311.GA6449@elte.hu> <1273492164.5605.3397.camel@twins> <20100510115344.GA11238@elte.hu> <4BE8931C.9070106@linux.vnet.ibm.com> <1273560419.5605.3426.camel@twins> <20100511072127.GB10421@elte.hu> <1273566031.30322.31.camel@minggr.sh.intel.com> <1273567815.5605.3491.camel@twins> <1273568620.30322.42.camel@minggr.sh.intel.com> <1273569154.5605.3499.camel@twins> Content-Type: text/plain Date: Tue, 11 May 2010 17:40:45 +0800 Message-Id: <1273570845.30322.59.camel@minggr.sh.intel.com> Mime-Version: 1.0 X-Mailer: Evolution 2.24.1 (2.24.1-2.fc10) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2010-05-11 at 17:12 +0800, Peter Zijlstra wrote: > On Tue, 2010-05-11 at 17:03 +0800, Lin Ming wrote: > > On Tue, 2010-05-11 at 16:50 +0800, Peter Zijlstra wrote: > > > On Tue, 2010-05-11 at 16:20 +0800, Lin Ming wrote: > > > > > > > How will this sysfs interface be used for userspace tool? > > > > > > > > /sys/devices/system/node/nodeN/node_events > > > > node_events/event_source_id > > > > > > > > node_events/local_misses/event_id > > > > /local_hits/event_id > > > > /remote_misses/event_id > > > > /remote_hits/event_id > > > > > > > > For example, to monitor node event local_misses on node 0, does it work > > > > as below? > > > > > > > > 1. perf top -e local_misses -n 0 (-n 0 means node 0) > > > > > > > > 2. read /sys/devices/system/node/node0/node_events/event_source_id to > > > > get the pmu_id > > > > > > > > 3. read /sys/devices/system/node/node0/node_events/local_misses/event_id > > > > to get the event_id > > > > > > > > 4. event_attr::pmu_id=pmu_id, event::config=event_id > > > > > > > > 5. other setting... > > > > > > > > 6. call syscall perf_event_open(....) > > > > > > No, you'll use event_source_id as perf_event_attr::type, use event_id as > > > perf_event_attr::config and then use a cpu-wide counter on a cpu > > > contained in node0. > > > > Is event_source_id a link to event_source class? > > No its an attribute of said class. > > > For example, 2 event sources on Nehalem > > /sys/class/event_sources/core_pmu > > /sys/class/event_sources/uncore_pmu > > > > Then, > > /sys/devices/system/node/nodeN/node_events/event_source_id is a link > > to /sys/class/event_sources/uncore_pmu. > > > /sys/devices/system/cpu/cpuN/cpu_hardware_events/event_source_id is a > > link to /sys/class/event_sources/core_pmu. > > The other way around, look in /sys/class/*/, they're all symlinks. /sys/devices/system/cpu/cpu0/cpu_hw_events/* /sys/devices/system/cpu/cpu0/cpu_hw_cache_events/* /sys/devices/system/cpu/cpu0/cpu_raw_events/* .... .... /sys/devices/system/cpu/cpuN/cpu_hw_events/* /sys/devices/system/cpu/cpuN/cpu_hw_cache_events/* /sys/devices/system/cpu/cpuN/cpu_raw_events/* Is /sys/class/event_sources/* looks like, /sys/class/event_sources/cpu_hw_events0 -> /sys/devices/system/cpu/cpu0/cpu_hw_events ... /sys/class/event_sources/cpu_hw_eventsN -> /sys/devices/system/cpu/cpuN/cpu_hw_events /sys/class/event_sources/cpu_hw_cache_events0 -> /sys/devices/system/cpu/cpu0/cpu_hw_events ... /sys/class/event_sources/cpu_hw_cache_eventsN -> /sys/devices/system/cpu/cpuN/cpu_hw_events ? > > > And, the event_source_id > > #cat /sys/class/event_sources/core_pmu > > 0 > > > #cat /sys/class/event_sources/uncore_pmu > > 1 > > You can't cat a directory. You'd cat something > like: /sys/class/event_sources/core_pmu/event_source_id > > And they would contain PERF_TYPE_* like things. > > So for the current CPU PMUs we'd already create 3 event classes, > cpu_hw_events, cpu_hw_cache_events, cpu_raw_events, with resp. > event_source_id of 0, 3 and 4. > > The new PMUs will use a dynamic range that starts at PERF_TYPE_MAX.