From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752620AbaHWAXa (ORCPT ); Fri, 22 Aug 2014 20:23:30 -0400 Received: from e7.ny.us.ibm.com ([32.97.182.137]:38518 "EHLO e7.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752365AbaHWAX3 (ORCPT ); Fri, 22 Aug 2014 20:23:29 -0400 Date: Fri, 22 Aug 2014 17:23:21 -0700 From: Sukadev Bhattiprolu To: Jiri Olsa Cc: mingo@kernel.org, Arnaldo Carvalho de Melo , ak@linux.intel.com, peterz@infradead.org, eranian@google.com, dev@codyps.com, Michael Ellerman , Anshuman Khandual , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH v2 00/14] Add support for parameterized events from sysfs Message-ID: <20140823002321.GA22172@us.ibm.com> References: <1408087583-32239-1-git-send-email-sukadev@linux.vnet.ibm.com> <20140820141545.GA3242@krava.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140820141545.GA3242@krava.brq.redhat.com> X-Operating-System: Linux 2.0.32 on an i486 User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14082300-5806-0000-0000-00000048EB85 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jiri Olsa [jolsa@redhat.com] wrote: | > Description of the sysfs contents when events are parameterized (copied from an | > included patch): | > | > Examples: | > | > domain=0x1,offset=0x8,starting_index=phys_cpu | > | > In the case of the last example, a value replacing "phys_cpu" | > would need to be provided by the user selecting the particular | > event. This is refered to as "event parameterization". All | > non-numerical values indicate an event parameter. | > | > Notes on how perf-list displays parameterized events (and how to use them, | > again culled from an included patch): | > | > PARAMETERIZED EVENTS | > -------------------- | > | > Some pmu events listed by 'perf-list' will be displayed with '?' in | > them. For example: | > | > hv_gpci/dtbp_ptitc,phys_processor_idx=?/ | > | > This means that when provided as an event, a value for | > phys_processor_idx must also be supplied. For example: | > | > perf stat -e 'hv_gpci/dtbp_ptitc,phys_processor_idx=0x2/' ... | | hi, | is the reason for this to document this field for event | in "events/" file? We are trying to document that for the parameters that have the ? in perf list, the parameter must be specified otherwise the event will not be recognized. | | Because once you have the field (phys_processor_idx) defined in | "formats/phys_processor_idx" you should be able to use it as in | your example: | | perf stat -e 'hv_gpci/dtbp_ptitc,phys_processor_idx=0x2/' | | without any changes For some events 'starting_index' refers to physical processor index as shown in the sysfs entry: $ cd /sys/bus/event_source/devices/hv_gpci/events $ cat dispatch_timebase_by_processor_processor_time_in_timebase_cycles request=0x10,starting_index=phys_processor_idx,counter_info_version=0x8,length=8,offset=0 and 'perf list' for this entry shows 'starting_index' with a ? indicating it is a requireed parameter. IIUC, rather than have the user specify a value for 'phys_processor_idx' -e hv_gpci/dtbp_ptitc,phys_processor_idx=4/' we would use following right ? -e hv_gpci/dtbp_ptitc,starting_index=4/' If so, I think the interface change makes sense. perf list would also show 'starting_index=?' for the event. But in the sysfs entry, rather than show 'starting_index=?', should we leave it as: 'starting_index=phys_processor_idx' For some events 'startind_index' refers to a physical processor id and for others it is virtual processor id. So, showing phys_processor_idx could serve as a hint. Michael, Cody, Ingo, Peter, let me know if you agree or have other comments on the inteface. Thanks, Sukadev | | thanks, | jirka