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 9F4A0C0032E for ; Wed, 25 Oct 2023 20:16:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229873AbjJYUQe (ORCPT ); Wed, 25 Oct 2023 16:16:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36572 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230062AbjJYUQ0 (ORCPT ); Wed, 25 Oct 2023 16:16:26 -0400 Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 798BE111 for ; Wed, 25 Oct 2023 13:16:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1698264984; x=1729800984; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=07Jlx1uQnb2mL/pNnjp+b/N9PsxbdweuVibmsH2J5a8=; b=Ia5qm27oIl+BI/qDnlvo/FXzhp/mHiWMnff0SP4gqguou4VwaZcwL+JT Xqp1YR12z0zxNX9kCF1vTVFRTNAr+z4txRJZ/zWHpnLACApvF9dnhMgOt OhPd8fGi7ezI67ZqaylEqHu5nSlTp92QPwfYYOgRSWcve0IYcfZhpZ6F3 bGcHtLjdS2QZE+DUjZzSPn2a9WUr3qybZ6ATzD0FEm5Xs8JbklkVrIc9a 1LMKCgO3yiHbY8czq5Wg9mD25swi7gaJLzwwJhphIMjVWl5yq+cJsvLPT JSIuFJCY1Sn564NbsI/H9+NXzF16Qu+ce6/CkfsNyB6WPBAjyh2RTu6cc g==; X-IronPort-AV: E=McAfee;i="6600,9927,10874"; a="377758194" X-IronPort-AV: E=Sophos;i="6.03,250,1694761200"; d="scan'208";a="377758194" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Oct 2023 13:16:22 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10874"; a="752459061" X-IronPort-AV: E=Sophos;i="6.03,250,1694761200"; d="scan'208";a="752459061" Received: from kanliang-dev.jf.intel.com ([10.165.154.102]) by orsmga007.jf.intel.com with ESMTP; 25 Oct 2023 13:16:22 -0700 From: kan.liang@linux.intel.com To: peterz@infradead.org, mingo@redhat.com, acme@kernel.org, linux-kernel@vger.kernel.org Cc: 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, Kan Liang , Sandipan Das , Ravi Bangoria , Athira Rajeev Subject: [PATCH V5 1/8] perf: Add branch stack counters Date: Wed, 25 Oct 2023 13:16:19 -0700 Message-Id: <20231025201626.3000228-1-kan.liang@linux.intel.com> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kan Liang Currently, the additional information of a branch entry is stored in a u64 space. With more and more information added, the space is running out. For example, the information of occurrences of events will be added for each branch. Two places were suggested to append the counters. https://lore.kernel.org/lkml/20230802215814.GH231007@hirez.programming.kicks-ass.net/ One place is right after the flags of each branch entry. It changes the existing struct perf_branch_entry. The later ARCH specific implementation has to be really careful to consistently pick the right struct. The other place is right after the entire struct perf_branch_stack. The disadvantage is that the pointer of the extra space has to be recorded. The common interface perf_sample_save_brstack() has to be updated. The latter is much straightforward, and should be easily understood and maintained. It is implemented in the patch. Add a new branch sample type, PERF_SAMPLE_BRANCH_COUNTERS, to indicate the event which is recorded in the branch info. The "u64 counters" may store the occurrences of several events. The information regarding the number of events/counters and the width of each counter should be exposed via sysfs as a reference for the perf tool. Define the branch_counter_nr and branch_counter_width ABI here. The support will be implemented later in the Intel-specific patch. Suggested-by: Peter Zijlstra (Intel) Signed-off-by: Kan Liang Cc: Sandipan Das Cc: Ravi Bangoria Cc: Athira Rajeev --- No changes since V4 .../testing/sysfs-bus-event_source-devices-caps | 6 ++++++ arch/powerpc/perf/core-book3s.c | 2 +- arch/x86/events/amd/core.c | 2 +- arch/x86/events/core.c | 2 +- arch/x86/events/intel/core.c | 2 +- arch/x86/events/intel/ds.c | 4 ++-- include/linux/perf_event.h | 17 ++++++++++++++++- include/uapi/linux/perf_event.h | 10 ++++++++++ kernel/events/core.c | 8 ++++++++ 9 files changed, 46 insertions(+), 7 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-bus-event_source-devices-caps b/Documentation/ABI/testing/sysfs-bus-event_source-devices-caps index 8757dcf41c08..a5f506f7d481 100644 --- a/Documentation/ABI/testing/sysfs-bus-event_source-devices-caps +++ b/Documentation/ABI/testing/sysfs-bus-event_source-devices-caps @@ -16,3 +16,9 @@ Description: Example output in powerpc: grep . /sys/bus/event_source/devices/cpu/caps/* /sys/bus/event_source/devices/cpu/caps/pmu_name:POWER9 + + The "branch_counter_nr" in the supported platform exposes the + maximum number of counters which can be shown in the u64 counters + of PERF_SAMPLE_BRANCH_COUNTERS, while the "branch_counter_width" + exposes the width of each counter. Both of them can be used by + the perf tool to parse the logged counters in each branch. diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index 8c1f7def596e..3c14596bbfaf 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -2313,7 +2313,7 @@ static void record_and_restart(struct perf_event *event, unsigned long val, struct cpu_hw_events *cpuhw; cpuhw = this_cpu_ptr(&cpu_hw_events); power_pmu_bhrb_read(event, cpuhw); - perf_sample_save_brstack(&data, event, &cpuhw->bhrb_stack); + perf_sample_save_brstack(&data, event, &cpuhw->bhrb_stack, NULL); } if (event->attr.sample_type & PERF_SAMPLE_DATA_SRC && diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c index e24976593a29..4ee6390b45c9 100644 --- a/arch/x86/events/amd/core.c +++ b/arch/x86/events/amd/core.c @@ -940,7 +940,7 @@ static int amd_pmu_v2_handle_irq(struct pt_regs *regs) continue; if (has_branch_stack(event)) - perf_sample_save_brstack(&data, event, &cpuc->lbr_stack); + perf_sample_save_brstack(&data, event, &cpuc->lbr_stack, NULL); if (perf_event_overflow(event, &data, regs)) x86_pmu_stop(event, 0); diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c index 40ad1425ffa2..40c9af124128 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -1702,7 +1702,7 @@ int x86_pmu_handle_irq(struct pt_regs *regs) perf_sample_data_init(&data, 0, event->hw.last_period); if (has_branch_stack(event)) - perf_sample_save_brstack(&data, event, &cpuc->lbr_stack); + perf_sample_save_brstack(&data, event, &cpuc->lbr_stack, NULL); if (perf_event_overflow(event, &data, regs)) x86_pmu_stop(event, 0); diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index a08f794a0e79..41a164764a84 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -3047,7 +3047,7 @@ static int handle_pmi_common(struct pt_regs *regs, u64 status) perf_sample_data_init(&data, 0, event->hw.last_period); if (has_branch_stack(event)) - perf_sample_save_brstack(&data, event, &cpuc->lbr_stack); + perf_sample_save_brstack(&data, event, &cpuc->lbr_stack, NULL); if (perf_event_overflow(event, &data, regs)) x86_pmu_stop(event, 0); diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c index dc8204afec76..1d309e97a629 100644 --- a/arch/x86/events/intel/ds.c +++ b/arch/x86/events/intel/ds.c @@ -1755,7 +1755,7 @@ static void setup_pebs_fixed_sample_data(struct perf_event *event, setup_pebs_time(event, data, pebs->tsc); if (has_branch_stack(event)) - perf_sample_save_brstack(data, event, &cpuc->lbr_stack); + perf_sample_save_brstack(data, event, &cpuc->lbr_stack, NULL); } static void adaptive_pebs_save_regs(struct pt_regs *regs, @@ -1912,7 +1912,7 @@ static void setup_pebs_adaptive_sample_data(struct perf_event *event, if (has_branch_stack(event)) { intel_pmu_store_pebs_lbrs(lbr); - perf_sample_save_brstack(data, event, &cpuc->lbr_stack); + perf_sample_save_brstack(data, event, &cpuc->lbr_stack, NULL); } } diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 0367d748fae0..7897ef066027 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1139,6 +1139,10 @@ static inline bool branch_sample_priv(const struct perf_event *event) return event->attr.branch_sample_type & PERF_SAMPLE_BRANCH_PRIV_SAVE; } +static inline bool branch_sample_counters(const struct perf_event *event) +{ + return event->attr.branch_sample_type & PERF_SAMPLE_BRANCH_COUNTERS; +} struct perf_sample_data { /* @@ -1173,6 +1177,7 @@ struct perf_sample_data { struct perf_callchain_entry *callchain; struct perf_raw_record *raw; struct perf_branch_stack *br_stack; + u64 *br_stack_cntr; union perf_sample_weight weight; union perf_mem_data_src data_src; u64 txn; @@ -1250,7 +1255,8 @@ static inline void perf_sample_save_raw_data(struct perf_sample_data *data, static inline void perf_sample_save_brstack(struct perf_sample_data *data, struct perf_event *event, - struct perf_branch_stack *brs) + struct perf_branch_stack *brs, + u64 *brs_cntr) { int size = sizeof(u64); /* nr */ @@ -1258,7 +1264,16 @@ static inline void perf_sample_save_brstack(struct perf_sample_data *data, size += sizeof(u64); size += brs->nr * sizeof(struct perf_branch_entry); + /* + * The extension space for counters is appended after the + * struct perf_branch_stack. It is used to store the occurrences + * of events of each branch. + */ + if (brs_cntr) + size += brs->nr * sizeof(u64); + data->br_stack = brs; + data->br_stack_cntr = brs_cntr; data->dyn_size += size; data->sample_flags |= PERF_SAMPLE_BRANCH_STACK; } diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index 39c6a250dd1b..4461f380425b 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -204,6 +204,8 @@ enum perf_branch_sample_type_shift { PERF_SAMPLE_BRANCH_PRIV_SAVE_SHIFT = 18, /* save privilege mode */ + PERF_SAMPLE_BRANCH_COUNTERS_SHIFT = 19, /* save occurrences of events on a branch */ + PERF_SAMPLE_BRANCH_MAX_SHIFT /* non-ABI */ }; @@ -235,6 +237,8 @@ enum perf_branch_sample_type { PERF_SAMPLE_BRANCH_PRIV_SAVE = 1U << PERF_SAMPLE_BRANCH_PRIV_SAVE_SHIFT, + PERF_SAMPLE_BRANCH_COUNTERS = 1U << PERF_SAMPLE_BRANCH_COUNTERS_SHIFT, + PERF_SAMPLE_BRANCH_MAX = 1U << PERF_SAMPLE_BRANCH_MAX_SHIFT, }; @@ -982,6 +986,12 @@ enum perf_event_type { * { u64 nr; * { u64 hw_idx; } && PERF_SAMPLE_BRANCH_HW_INDEX * { u64 from, to, flags } lbr[nr]; + * # + * # The format of the counters is decided by the + * # "branch_counter_nr" and "branch_counter_width", + * # which are defined in the ABI. + * # + * { u64 counters; } cntr[nr] && PERF_SAMPLE_BRANCH_COUNTERS * } && PERF_SAMPLE_BRANCH_STACK * * { u64 abi; # enum perf_sample_regs_abi diff --git a/kernel/events/core.c b/kernel/events/core.c index 3eb26c2c6e65..d27ffd80ed67 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7341,6 +7341,14 @@ void perf_output_sample(struct perf_output_handle *handle, if (branch_sample_hw_index(event)) perf_output_put(handle, data->br_stack->hw_idx); perf_output_copy(handle, data->br_stack->entries, size); + /* + * Add the extension space which is appended + * right after the struct perf_branch_stack. + */ + if (data->br_stack_cntr) { + size = data->br_stack->nr * sizeof(u64); + perf_output_copy(handle, data->br_stack_cntr, size); + } } else { /* * we always store at least the value of nr -- 2.35.1