From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark.rutland@arm.com (Mark Rutland) Date: Thu, 20 Apr 2017 09:53:00 +0100 Subject: [PATCH 3/3] perf tool, arm64, thunderx2: Add implementation defined events for ThunderX2 In-Reply-To: References: <1491291403-29893-1-git-send-email-ganapatrao.kulkarni@cavium.com> <1491291403-29893-4-git-send-email-ganapatrao.kulkarni@cavium.com> <20170404122828.GB8551@leverpostej> <20170405100548.GA10833@leverpostej> <20170406095533.GB29947@leverpostej> Message-ID: <20170420085259.GD31436@leverpostej> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Apr 19, 2017 at 11:37:31PM +0530, Ganapatrao Kulkarni wrote: > Hi Mark, Hi, > On Thu, Apr 6, 2017 at 3:25 PM, Mark Rutland wrote: > > On Thu, Apr 06, 2017 at 09:50:33AM +0530, Ganapatrao Kulkarni wrote: > >> On Wed, Apr 5, 2017 at 3:35 PM, Mark Rutland wrote: > >> > On Wed, Apr 05, 2017 at 02:42:39PM +0530, Ganapatrao Kulkarni wrote: > >> >> On Tue, Apr 4, 2017 at 5:58 PM, Mark Rutland wrote: > >> >> > On Tue, Apr 04, 2017 at 01:06:43PM +0530, Ganapatrao Kulkarni wrote: > > > >> >> >> + "CPU" :"armv8_pmuv3_0" > >> >> > > >> >> > Please let's not hard-code the name like this. Surely we can get rid of this? > >> >> > > >> >> > The kernel doesn't currently name PMUs as armv8_pmuv3_*, and as that can > >> >> > differ across DT/ACPI and in big.LITTLE, I don't think it makes sense to > >> >> > try to rely one particular string regardless. > >> >> > >> >> This string/name is fixed for a platform. having name here is essential to > >> >> know which devices among pmu (armv8_pmuv3_0, breakpoint, software) > >> >> devices, these jevents to be added. > >> >> also this json file is specific to a arch/soc/board, it is not a > >> >> generic file to be common. > >> > > >> > This file describe the events of a CPU PMU, and CPUs are not specific to > >> > a platform in general. There are many systems using Cortex-A57, for > >> > example. > >> > > >> > Across big.LITTLE SoCs with Cortex-A57, there's no guarantee as to > >> > whether the Cortex-A57 cores would be named armv8_pmuv3_0, or > >> > armv8_pmuv3_1, etc. This would depend on the boot CPU, probe order of > >> > secondaries, etc. > > some of the applications(perf etc) use sysfs files of perf PMU CORE devices. > at present the names are created as per SOC/platform like > armv8_pmuv3, armv8_cavium_thunder, armv8_cortex_a57 etc. > > cpu_pmu->name = "armv8_cavium_thunder"; > > can we please have common name similar to x86(cpu) and call them as > cpu_0 and cpu_1? I don't see how that helps in this case? I'd rather that we expose some mechanism to determine whether a PMU is a CPU PMU, other than the name. Userspace can then throw away the name if it so wishes, and it doesn't have the potential to break existing users. Thanks, Mark. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030887AbdDTIx7 (ORCPT ); Thu, 20 Apr 2017 04:53:59 -0400 Received: from foss.arm.com ([217.140.101.70]:51084 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S943823AbdDTIx1 (ORCPT ); Thu, 20 Apr 2017 04:53:27 -0400 Date: Thu, 20 Apr 2017 09:53:00 +0100 From: Mark Rutland To: Ganapatrao Kulkarni Cc: Ganapatrao Kulkarni , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , Will Deacon , Catalin Marinas , acme@kernel.org, alexander.shishkin@linux.intel.com, peterz@infradead.org, Ingo Molnar , jnair@caviumnetworks.com, "Andrew.Pinski@caviumnetworks.com" Subject: Re: [PATCH 3/3] perf tool, arm64, thunderx2: Add implementation defined events for ThunderX2 Message-ID: <20170420085259.GD31436@leverpostej> References: <1491291403-29893-1-git-send-email-ganapatrao.kulkarni@cavium.com> <1491291403-29893-4-git-send-email-ganapatrao.kulkarni@cavium.com> <20170404122828.GB8551@leverpostej> <20170405100548.GA10833@leverpostej> <20170406095533.GB29947@leverpostej> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 19, 2017 at 11:37:31PM +0530, Ganapatrao Kulkarni wrote: > Hi Mark, Hi, > On Thu, Apr 6, 2017 at 3:25 PM, Mark Rutland wrote: > > On Thu, Apr 06, 2017 at 09:50:33AM +0530, Ganapatrao Kulkarni wrote: > >> On Wed, Apr 5, 2017 at 3:35 PM, Mark Rutland wrote: > >> > On Wed, Apr 05, 2017 at 02:42:39PM +0530, Ganapatrao Kulkarni wrote: > >> >> On Tue, Apr 4, 2017 at 5:58 PM, Mark Rutland wrote: > >> >> > On Tue, Apr 04, 2017 at 01:06:43PM +0530, Ganapatrao Kulkarni wrote: > > > >> >> >> + "CPU" :"armv8_pmuv3_0" > >> >> > > >> >> > Please let's not hard-code the name like this. Surely we can get rid of this? > >> >> > > >> >> > The kernel doesn't currently name PMUs as armv8_pmuv3_*, and as that can > >> >> > differ across DT/ACPI and in big.LITTLE, I don't think it makes sense to > >> >> > try to rely one particular string regardless. > >> >> > >> >> This string/name is fixed for a platform. having name here is essential to > >> >> know which devices among pmu (armv8_pmuv3_0, breakpoint, software) > >> >> devices, these jevents to be added. > >> >> also this json file is specific to a arch/soc/board, it is not a > >> >> generic file to be common. > >> > > >> > This file describe the events of a CPU PMU, and CPUs are not specific to > >> > a platform in general. There are many systems using Cortex-A57, for > >> > example. > >> > > >> > Across big.LITTLE SoCs with Cortex-A57, there's no guarantee as to > >> > whether the Cortex-A57 cores would be named armv8_pmuv3_0, or > >> > armv8_pmuv3_1, etc. This would depend on the boot CPU, probe order of > >> > secondaries, etc. > > some of the applications(perf etc) use sysfs files of perf PMU CORE devices. > at present the names are created as per SOC/platform like > armv8_pmuv3, armv8_cavium_thunder, armv8_cortex_a57 etc. > > cpu_pmu->name = "armv8_cavium_thunder"; > > can we please have common name similar to x86(cpu) and call them as > cpu_0 and cpu_1? I don't see how that helps in this case? I'd rather that we expose some mechanism to determine whether a PMU is a CPU PMU, other than the name. Userspace can then throw away the name if it so wishes, and it doesn't have the potential to break existing users. Thanks, Mark.