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 5BC66C4332F for ; Mon, 6 Nov 2023 21:12:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233040AbjKFVMd (ORCPT ); Mon, 6 Nov 2023 16:12:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37142 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231364AbjKFVMb (ORCPT ); Mon, 6 Nov 2023 16:12:31 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D6EE0AF for ; Mon, 6 Nov 2023 13:12:28 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 44A7EC433C7; Mon, 6 Nov 2023 21:12:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699305148; bh=4FfF6FSoLzUKkH7FfpBirtFkvFkbBq8zo79wC88C5tM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HWPW6jofDuVjfYHlUYRkdq5N9sLOcuHq9uXkomd2dlACnm0/4PcS9lKTIEvU+OiBW 13uaKqEK2ntMsmrHSK1PN+94wYJW8OfHXxHtU6iPpftCU3Nh3ati3LpOCUUsMQIj1E uLmah2vdP6Ou5yPIzI71EzKmN06c2MncNt+ickiUaC6AOsXjHeVqmNAKShQNbH6Mtc O5c1R2mvYd8YmyymL1Anlmau1sDTjq/X8eEpK4EIk1Z6+lDRAN6555Ab1TF87ffYsW nsEJXeZmatCgEDpK5hAVAiOmD+uylQnc3+UqM4GFOPNd6msg76PlD6/Knq3ryeB1tw 20ClMg7aC/p5w== Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id 6B8084035D; Mon, 6 Nov 2023 18:12:25 -0300 (-03) Date: Mon, 6 Nov 2023 18:12:25 -0300 From: Arnaldo Carvalho de Melo To: kan.liang@linux.intel.com Cc: peterz@infradead.org, mingo@redhat.com, linux-kernel@vger.kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, namhyung@kernel.org, irogers@google.com, adrian.hunter@intel.com, ak@linux.intel.com, eranian@google.com, alexey.v.bayduraev@linux.intel.com, tinghao.zhang@intel.com Subject: Re: [PATCH V5 2/8] perf/x86: Add PERF_X86_EVENT_NEEDS_BRANCH_STACK flag Message-ID: References: <20231025201626.3000228-1-kan.liang@linux.intel.com> <20231025201626.3000228-2-kan.liang@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231025201626.3000228-2-kan.liang@linux.intel.com> X-Url: http://acmel.wordpress.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Wed, Oct 25, 2023 at 01:16:20PM -0700, kan.liang@linux.intel.com escreveu: > From: Kan Liang > > Currently, branch_sample_type !=0 is used to check whether a branch > stack setup is required. But it doesn't check the sample type, > unnecessary branch stack setup may be done for a counting event. E.g., > perf record -e "{branch-instructions,branch-misses}:S" -j any > Also, the event only with the new PERF_SAMPLE_BRANCH_COUNTERS branch > sample type may not require a branch stack setup either. > > Add a new flag NEEDS_BRANCH_STACK to indicate whether the event requires > a branch stack setup. Replace the needs_branch_stack() by checking the > new flag. > > The counting event check is implemented here. The later patch will take > the new PERF_SAMPLE_BRANCH_COUNTERS into account. > > Signed-off-by: Kan Liang > --- > > No changes since V4 So I saw this on tip/perf/urgent, I'm picking the tools bits then. - Arnaldo > arch/x86/events/intel/core.c | 14 +++++++++++--- > arch/x86/events/perf_event_flags.h | 1 + > 2 files changed, 12 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c > index 41a164764a84..a99449c0d77c 100644 > --- a/arch/x86/events/intel/core.c > +++ b/arch/x86/events/intel/core.c > @@ -2527,9 +2527,14 @@ static void intel_pmu_assign_event(struct perf_event *event, int idx) > perf_report_aux_output_id(event, idx); > } > > +static __always_inline bool intel_pmu_needs_branch_stack(struct perf_event *event) > +{ > + return event->hw.flags & PERF_X86_EVENT_NEEDS_BRANCH_STACK; > +} > + > static void intel_pmu_del_event(struct perf_event *event) > { > - if (needs_branch_stack(event)) > + if (intel_pmu_needs_branch_stack(event)) > intel_pmu_lbr_del(event); > if (event->attr.precise_ip) > intel_pmu_pebs_del(event); > @@ -2820,7 +2825,7 @@ static void intel_pmu_add_event(struct perf_event *event) > { > if (event->attr.precise_ip) > intel_pmu_pebs_add(event); > - if (needs_branch_stack(event)) > + if (intel_pmu_needs_branch_stack(event)) > intel_pmu_lbr_add(event); > } > > @@ -3897,7 +3902,10 @@ static int intel_pmu_hw_config(struct perf_event *event) > x86_pmu.pebs_aliases(event); > } > > - if (needs_branch_stack(event)) { > + if (needs_branch_stack(event) && is_sampling_event(event)) > + event->hw.flags |= PERF_X86_EVENT_NEEDS_BRANCH_STACK; > + > + if (intel_pmu_needs_branch_stack(event)) { > ret = intel_pmu_setup_lbr_filter(event); > if (ret) > return ret; > diff --git a/arch/x86/events/perf_event_flags.h b/arch/x86/events/perf_event_flags.h > index 1dc19b9b4426..a1685981c520 100644 > --- a/arch/x86/events/perf_event_flags.h > +++ b/arch/x86/events/perf_event_flags.h > @@ -20,3 +20,4 @@ PERF_ARCH(TOPDOWN, 0x04000) /* Count Topdown slots/metrics events */ > PERF_ARCH(PEBS_STLAT, 0x08000) /* st+stlat data address sampling */ > PERF_ARCH(AMD_BRS, 0x10000) /* AMD Branch Sampling */ > PERF_ARCH(PEBS_LAT_HYBRID, 0x20000) /* ld and st lat for hybrid */ > +PERF_ARCH(NEEDS_BRANCH_STACK, 0x40000) /* require branch stack setup */ > -- > 2.35.1 > -- - Arnaldo