From nobody Sat Feb 7 11:38:11 2026 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 30338C001B0 for ; Mon, 10 Jul 2023 12:22:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231228AbjGJMWI (ORCPT ); Mon, 10 Jul 2023 08:22:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58986 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229517AbjGJMWD (ORCPT ); Mon, 10 Jul 2023 08:22:03 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 782BFB1; Mon, 10 Jul 2023 05:22:02 -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 694C4D75; Mon, 10 Jul 2023 05:22:44 -0700 (PDT) Received: from e127643.arm.com (unknown [10.57.29.214]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 534343F67D; Mon, 10 Jul 2023 05:21:59 -0700 (PDT) From: James Clark To: linux-perf-users@vger.kernel.org, irogers@google.com Cc: James Clark , 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 Subject: [PATCH 1/4] arm_pmu: Add PERF_PMU_CAP_EXTENDED_HW_TYPE capability Date: Mon, 10 Jul 2023 13:21:34 +0100 Message-Id: <20230710122138.1450930-2-james.clark@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230710122138.1450930-1-james.clark@arm.com> References: <20230710122138.1450930-1-james.clark@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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_CACH= E") Suggested-by: Ian Rogers Signed-off-by: James Clark Acked-by: Ian Rogers --- 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 + * PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE events on a + * specific PMU. */ - .capabilities =3D PERF_PMU_CAP_HETEROGENEOUS_CPUS | PERF_PMU_CAP_EXTENDE= D_REGS, + .capabilities =3D PERF_PMU_CAP_HETEROGENEOUS_CPUS | PERF_PMU_CAP_EXTENDE= D_REGS | + PERF_PMU_CAP_EXTENDED_HW_TYPE, }; =20 pmu->attr_groups[ARMPMU_ATTR_GROUP_COMMON] =3D --=20 2.34.1 From nobody Sat Feb 7 11:38:11 2026 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 E13E8C001B0 for ; Mon, 10 Jul 2023 12:22:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231358AbjGJMWL (ORCPT ); Mon, 10 Jul 2023 08:22:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59056 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231205AbjGJMWH (ORCPT ); Mon, 10 Jul 2023 08:22:07 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 00289FF; Mon, 10 Jul 2023 05:22:05 -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 EF973113E; Mon, 10 Jul 2023 05:22:47 -0700 (PDT) Received: from e127643.arm.com (unknown [10.57.29.214]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id D04C03F67D; Mon, 10 Jul 2023 05:22:02 -0700 (PDT) From: James Clark To: linux-perf-users@vger.kernel.org, irogers@google.com Cc: James Clark , 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 Subject: [PATCH 2/4] perf/x86: Remove unused PERF_PMU_CAP_HETEROGENEOUS_CPUS capability Date: Mon, 10 Jul 2023 13:21:35 +0100 Message-Id: <20230710122138.1450930-3-james.clark@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230710122138.1450930-1-james.clark@arm.com> References: <20230710122138.1450930-1-james.clark@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Since commit bd2756811766 ("perf: Rewrite core context handling") the relationship between perf_event_context and PMUs has changed so that the error scenario that PERF_PMU_CAP_HETEROGENEOUS_CPUS originally silenced no longer exists. Remove the capability to avoid confusion that it actually influences any perf core behavior. This change should be a no-op. Signed-off-by: James Clark Acked-by: Ian Rogers --- arch/x86/events/core.c | 1 - 1 file changed, 1 deletion(-) diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c index 9d248703cbdd..2353aaf0b248 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -2168,7 +2168,6 @@ static int __init init_hw_perf_events(void) hybrid_pmu->pmu =3D pmu; hybrid_pmu->pmu.type =3D -1; hybrid_pmu->pmu.attr_update =3D x86_pmu.attr_update; - hybrid_pmu->pmu.capabilities |=3D PERF_PMU_CAP_HETEROGENEOUS_CPUS; hybrid_pmu->pmu.capabilities |=3D PERF_PMU_CAP_EXTENDED_HW_TYPE; =20 err =3D perf_pmu_register(&hybrid_pmu->pmu, hybrid_pmu->name, --=20 2.34.1 From nobody Sat Feb 7 11:38:11 2026 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 C7E61EB64D9 for ; Mon, 10 Jul 2023 12:22:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231552AbjGJMWS (ORCPT ); Mon, 10 Jul 2023 08:22:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59184 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231375AbjGJMWL (ORCPT ); Mon, 10 Jul 2023 08:22:11 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 9E765DB; Mon, 10 Jul 2023 05:22:09 -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 722B611FB; Mon, 10 Jul 2023 05:22:51 -0700 (PDT) Received: from e127643.arm.com (unknown [10.57.29.214]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 5B6B73F67D; Mon, 10 Jul 2023 05:22:06 -0700 (PDT) From: James Clark To: linux-perf-users@vger.kernel.org, irogers@google.com Cc: James Clark , 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 Subject: [PATCH 3/4] arm_pmu: Remove unused PERF_PMU_CAP_HETEROGENEOUS_CPUS capability Date: Mon, 10 Jul 2023 13:21:36 +0100 Message-Id: <20230710122138.1450930-4-james.clark@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230710122138.1450930-1-james.clark@arm.com> References: <20230710122138.1450930-1-james.clark@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Since commit bd2756811766 ("perf: Rewrite core context handling") the relationship between perf_event_context and PMUs has changed so that the error scenario that PERF_PMU_CAP_HETEROGENEOUS_CPUS originally silenced no longer exists. Remove the capability and associated comment to avoid confusion that it actually influences any perf core behavior. This change should be a no-op. Signed-off-by: James Clark Acked-by: Ian Rogers --- drivers/perf/arm_pmu.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c index d8844a9461a2..297906df6628 100644 --- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c @@ -872,15 +872,12 @@ struct arm_pmu *armpmu_alloc(void) .attr_groups =3D pmu->attr_groups, /* * This is a CPU PMU potentially in a heterogeneous - * 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). - * + * configuration (e.g. big.LITTLE) so * PERF_PMU_CAP_EXTENDED_HW_TYPE is required to open the legacy * PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE events on a * specific PMU. */ - .capabilities =3D PERF_PMU_CAP_HETEROGENEOUS_CPUS | PERF_PMU_CAP_EXTENDE= D_REGS | + .capabilities =3D PERF_PMU_CAP_EXTENDED_REGS | PERF_PMU_CAP_EXTENDED_HW_TYPE, }; =20 --=20 2.34.1 From nobody Sat Feb 7 11:38:11 2026 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 25C90EB64DA for ; Mon, 10 Jul 2023 12:22:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231452AbjGJMWa (ORCPT ); Mon, 10 Jul 2023 08:22:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59270 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231513AbjGJMWR (ORCPT ); Mon, 10 Jul 2023 08:22:17 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 15D0C13D; Mon, 10 Jul 2023 05:22:13 -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 F37AED75; Mon, 10 Jul 2023 05:22:54 -0700 (PDT) Received: from e127643.arm.com (unknown [10.57.29.214]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id D487E3F67D; Mon, 10 Jul 2023 05:22:09 -0700 (PDT) From: James Clark To: linux-perf-users@vger.kernel.org, irogers@google.com Cc: James Clark , 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 Subject: [PATCH 4/4] perf: Remove unused PERF_PMU_CAP_HETEROGENEOUS_CPUS capability Date: Mon, 10 Jul 2023 13:21:37 +0100 Message-Id: <20230710122138.1450930-5-james.clark@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230710122138.1450930-1-james.clark@arm.com> References: <20230710122138.1450930-1-james.clark@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Since commit bd2756811766 ("perf: Rewrite core context handling") the relationship between perf_event_context and PMUs has changed so that the error scenario that PERF_PMU_CAP_HETEROGENEOUS_CPUS originally silenced no longer exists. Remove the capability to avoid confusion that it actually influences any perf core behavior. This change should be a no-op. Signed-off-by: James Clark Acked-by: Ian Rogers --- include/linux/perf_event.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index d5628a7b5eaa..3f4d941fd6c5 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -288,7 +288,7 @@ struct perf_event_pmu_context; #define PERF_PMU_CAP_EXTENDED_REGS 0x0008 #define PERF_PMU_CAP_EXCLUSIVE 0x0010 #define PERF_PMU_CAP_ITRACE 0x0020 -#define PERF_PMU_CAP_HETEROGENEOUS_CPUS 0x0040 +/* Unused 0x0040 */ #define PERF_PMU_CAP_NO_EXCLUDE 0x0080 #define PERF_PMU_CAP_AUX_OUTPUT 0x0100 #define PERF_PMU_CAP_EXTENDED_HW_TYPE 0x0200 --=20 2.34.1