From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4C06CEB64DC for ; Tue, 11 Jul 2023 14:13:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231458AbjGKOMx (ORCPT ); Tue, 11 Jul 2023 10:12:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49838 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231876AbjGKOMu (ORCPT ); Tue, 11 Jul 2023 10:12:50 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 3D02512A; Tue, 11 Jul 2023 07:12:49 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 33DC91FB; Tue, 11 Jul 2023 07:13:31 -0700 (PDT) Received: from [10.57.30.34] (unknown [10.57.30.34]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 559C13F740; Tue, 11 Jul 2023 07:12:46 -0700 (PDT) Message-ID: <597f53e0-5a5b-75a1-4054-253630a941f2@arm.com> Date: Tue, 11 Jul 2023 15:12:44 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.9.0 Subject: Re: [PATCH 1/4] arm_pmu: Add PERF_PMU_CAP_EXTENDED_HW_TYPE capability Content-Language: en-US To: Anshuman Khandual Cc: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Adrian Hunter , Thomas Gleixner , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Will Deacon , Kan Liang , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org, irogers@google.com References: <20230710122138.1450930-1-james.clark@arm.com> <20230710122138.1450930-2-james.clark@arm.com> From: James Clark In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/07/2023 13:01, Anshuman Khandual wrote: > > > On 7/10/23 17:51, James Clark wrote: >> This capability gives us the ability to open PERF_TYPE_HARDWARE and >> PERF_TYPE_HW_CACHE events on a specific PMU for free. All the >> implementation is contained in the Perf core and tool code so no change >> to the Arm PMU driver is needed. >> >> The following basic use case now results in Perf opening the event on >> all PMUs rather than picking only one in an unpredictable way: >> >> $ perf stat -e cycles -- taskset --cpu-list 0,1 stress -c 2 >> >> Performance counter stats for 'taskset --cpu-list 0,1 stress -c 2': >> >> 963279620 armv8_cortex_a57/cycles/ (99.19%) >> 752745657 armv8_cortex_a53/cycles/ (94.80%) >> >> Fixes: 55bcf6ef314a ("perf: Extend PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE") >> Suggested-by: Ian Rogers >> Signed-off-by: James Clark >> --- >> drivers/perf/arm_pmu.c | 7 ++++++- >> 1 file changed, 6 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c >> index 277e29fbd504..d8844a9461a2 100644 >> --- a/drivers/perf/arm_pmu.c >> +++ b/drivers/perf/arm_pmu.c >> @@ -875,8 +875,13 @@ struct arm_pmu *armpmu_alloc(void) >> * configuration (e.g. big.LITTLE). This is not an uncore PMU, >> * and we have taken ctx sharing into account (e.g. with our >> * pmu::filter callback and pmu::event_init group validation). >> + * >> + * PERF_PMU_CAP_EXTENDED_HW_TYPE is required to open the legacy > > s/legacy/generic ? These hardware events are still around. True, I thought I saw it mentioned that way somewhere, but I can probably just remove it altogether. PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE is enough. > >> + * PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE events on a >> + * specific PMU. >> */ >> - .capabilities = PERF_PMU_CAP_HETEROGENEOUS_CPUS | PERF_PMU_CAP_EXTENDED_REGS, >> + .capabilities = PERF_PMU_CAP_HETEROGENEOUS_CPUS | PERF_PMU_CAP_EXTENDED_REGS | >> + PERF_PMU_CAP_EXTENDED_HW_TYPE, >> }; >> >> pmu->attr_groups[ARMPMU_ATTR_GROUP_COMMON] =