Messages in this thread | | | Date | Thu, 1 Sep 2022 08:42:05 -0400 | Subject | Re: [PATCH 3/6] perf: Use sample_flags for branch stack | From | "Liang, Kan" <> |
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On 2022-08-31 6:47 p.m., Namhyung Kim wrote: > On Wed, Aug 31, 2022 at 07:55:11AM -0700, kan.liang@linux.intel.com wrote: >> From: Kan Liang <kan.liang@linux.intel.com> >> >> Use the new sample_flags to indicate whether the branch stack is filled >> by the PMU driver. >> >> Remove the br_stack from the perf_sample_data_init() to minimize the number >> of cache lines touched. >> >> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> >> --- >> arch/powerpc/perf/core-book3s.c | 1 + >> arch/x86/events/core.c | 4 +++- >> arch/x86/events/intel/core.c | 4 +++- >> arch/x86/events/intel/ds.c | 5 ++++- >> include/linux/perf_event.h | 4 ++-- >> kernel/events/core.c | 4 ++-- >> 6 files changed, 15 insertions(+), 7 deletions(-) > > Looks like you need to update AMD LBR code in amd_pmu_v2_handle_irq().
Right, the patch is on the top of the 6.0-rc, which doesn't include the AMD LBR code yet. I will re-base on Peter's perf/core.
Thanks, Kan
> > Thanks, > Namhyung > >> >> diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c >> index 13919eb96931..1ad1efdb33f9 100644 >> --- a/arch/powerpc/perf/core-book3s.c >> +++ b/arch/powerpc/perf/core-book3s.c >> @@ -2297,6 +2297,7 @@ static void record_and_restart(struct perf_event *event, unsigned long val, >> cpuhw = this_cpu_ptr(&cpu_hw_events); >> power_pmu_bhrb_read(event, cpuhw); >> data.br_stack = &cpuhw->bhrb_stack; >> + data.sample_flags |= PERF_SAMPLE_BRANCH_STACK; >> } >> >> if (event->attr.sample_type & PERF_SAMPLE_DATA_SRC && >> diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c >> index f969410d0c90..bb34a28fa71b 100644 >> --- a/arch/x86/events/core.c >> +++ b/arch/x86/events/core.c >> @@ -1714,8 +1714,10 @@ int x86_pmu_handle_irq(struct pt_regs *regs) >> >> perf_sample_data_init(&data, 0, event->hw.last_period); >> >> - if (has_branch_stack(event)) >> + if (has_branch_stack(event)) { >> data.br_stack = &cpuc->lbr_stack; >> + data.sample_flags |= PERF_SAMPLE_BRANCH_STACK; >> + } >> >> 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 4fce2bdbbf87..36f95894dd1c 100644 >> --- a/arch/x86/events/intel/core.c >> +++ b/arch/x86/events/intel/core.c >> @@ -3004,8 +3004,10 @@ 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)) >> + if (has_branch_stack(event)) { >> data.br_stack = &cpuc->lbr_stack; >> + data.sample_flags |= PERF_SAMPLE_BRANCH_STACK; >> + } >> >> 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 3af24c4891fb..d5f3007af59d 100644 >> --- a/arch/x86/events/intel/ds.c >> +++ b/arch/x86/events/intel/ds.c >> @@ -1645,8 +1645,10 @@ static void setup_pebs_fixed_sample_data(struct perf_event *event, >> data->sample_flags |= PERF_SAMPLE_TIME; >> } >> >> - if (has_branch_stack(event)) >> + if (has_branch_stack(event)) { >> data->br_stack = &cpuc->lbr_stack; >> + data->sample_flags |= PERF_SAMPLE_BRANCH_STACK; >> + } >> } >> >> static void adaptive_pebs_save_regs(struct pt_regs *regs, >> @@ -1796,6 +1798,7 @@ static void setup_pebs_adaptive_sample_data(struct perf_event *event, >> if (has_branch_stack(event)) { >> intel_pmu_store_pebs_lbrs(lbr); >> data->br_stack = &cpuc->lbr_stack; >> + data->sample_flags |= PERF_SAMPLE_BRANCH_STACK; >> } >> } >> >> diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h >> index b0ebbb1377b9..2aec1765b3d5 100644 >> --- a/include/linux/perf_event.h >> +++ b/include/linux/perf_event.h >> @@ -1010,7 +1010,6 @@ struct perf_sample_data { >> u64 sample_flags; >> u64 addr; >> struct perf_raw_record *raw; >> - struct perf_branch_stack *br_stack; >> u64 period; >> union perf_sample_weight weight; >> u64 txn; >> @@ -1020,6 +1019,8 @@ struct perf_sample_data { >> * The other fields, optionally {set,used} by >> * perf_{prepare,output}_sample(). >> */ >> + struct perf_branch_stack *br_stack; >> + >> u64 type; >> u64 ip; >> struct { >> @@ -1060,7 +1061,6 @@ static inline void perf_sample_data_init(struct perf_sample_data *data, >> data->sample_flags = 0; >> data->addr = addr; >> data->raw = NULL; >> - data->br_stack = NULL; >> data->period = period; >> data->weight.full = 0; >> data->data_src.val = PERF_MEM_NA; >> diff --git a/kernel/events/core.c b/kernel/events/core.c >> index c9b9cb79231a..104c0c9f4e6f 100644 >> --- a/kernel/events/core.c >> +++ b/kernel/events/core.c >> @@ -7052,7 +7052,7 @@ void perf_output_sample(struct perf_output_handle *handle, >> } >> >> if (sample_type & PERF_SAMPLE_BRANCH_STACK) { >> - if (data->br_stack) { >> + if (data->sample_flags & PERF_SAMPLE_BRANCH_STACK) { >> size_t size; >> >> size = data->br_stack->nr >> @@ -7358,7 +7358,7 @@ void perf_prepare_sample(struct perf_event_header *header, >> >> if (sample_type & PERF_SAMPLE_BRANCH_STACK) { >> int size = sizeof(u64); /* nr */ >> - if (data->br_stack) { >> + if (data->sample_flags & PERF_SAMPLE_BRANCH_STACK) { >> if (perf_sample_save_hw_index(event)) >> size += sizeof(u64); >> >> -- >> 2.35.1 >> >>
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