Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751872AbbH1PKw (ORCPT ); Fri, 28 Aug 2015 11:10:52 -0400 Received: from mail-wi0-f176.google.com ([209.85.212.176]:37983 "EHLO mail-wi0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751779AbbH1PKr (ORCPT ); Fri, 28 Aug 2015 11:10:47 -0400 MIME-Version: 1.0 In-Reply-To: <37D7C6CF3E00A74B8858931C1DB2F077018F4B39@SHSMSX103.ccr.corp.intel.com> References: <1437986776-8438-1-git-send-email-kan.liang@intel.com> <20150806154424.GR19282@twins.programming.kicks-ass.net> <37D7C6CF3E00A74B8858931C1DB2F077018D334D@SHSMSX103.ccr.corp.intel.com> <37D7C6CF3E00A74B8858931C1DB2F077018F2AD6@SHSMSX103.ccr.corp.intel.com> <37D7C6CF3E00A74B8858931C1DB2F077018F4B39@SHSMSX103.ccr.corp.intel.com> Date: Fri, 28 Aug 2015 08:10:46 -0700 Message-ID: Subject: Re: [PATCH V2 1/1] perf/x86: Add Intel power cstate PMUs support From: Stephane Eranian To: "Liang, Kan" Cc: Peter Zijlstra , "mingo@redhat.com" , Arnaldo Carvalho de Melo , "ak@linux.intel.com" , LKML Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2829 Lines: 64 On Fri, Aug 28, 2015 at 8:00 AM, Liang, Kan wrote: > > >> On Tue, Aug 25, 2015 at 1:15 PM, Liang, Kan wrote: >> > >> >> >> > >> >> >> I understand that these metrics are useful and needed however if I >> >> >> look at the broader picture I see many PMUs doing similar things >> >> >> or appearing different when they are actually very close. It would >> >> >> be nice to have a more unified approach. You have RAPL (client, >> >> >> server) which appears as the power PMU. You have the PCU uncore >> on >> >> >> servers which also provides C-state residency info. Yet, all these >> >> >> appear differently and expose events with different names. >> >> >> I think we could benefit from a more unifie approach here such >> >> >> that you would be able to do >> >> >> >> >> >> $ perf stat -a -e power/c6-residency/, power/energy-pkg/ >> >> >> >> >> >> on client and server without having to change the pmu name of the >> >> >> event names. >> >> > >> >> > Yes, I agree. I'll think about it. >> >> > >> > >> > Hi Stephane, >> > >> > I thought more about your suggestion regarding to create a unified >> > power PMU for all related events include RAPL and residency. >> > It looks we can benefit from a simple unified name, but it also brings >> > too much confusion. >> > - cstate residency is the time of the core/socket in specific cstate. >> > While RAPL event is the power core/socket which consumed. >> > They have different concepts. >> > - cstate residency includes both per-core and per-socket events. >> > RAPL events is only per-socket. So the CPU mask is different. >> > It's very confused that the events in same PMU has different CPU >> mask. >> > >> > So I think it should be better to use different PMUs for RAPL and >> residency. >> > >> > What do you think? >> > >> Well, you are maybe confusing events with PMU. If you look at the core >> PMU, it cover many events measuring vastly different aspects of the core. >> Some events are per-thread, others are per-core. >> >> Here, I was thinking it would be good to have some power// PMU with >> many events covering cstate residency, energy consumption. And yes, >> some events would be per-socket, others per-core. > > So you agree to create two new cstate PMUs (per-core and per-socket) to > cover cstate residency? > If so, I will start to implement the V3 version for two new PMUs. > I did not say that. Instead I said there is some benefits in having everything under a power// PMU, including possibly portability to other non x86 architectures. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/