Messages in this thread | | | Date | Wed, 31 Aug 2022 15:47:13 -0700 | From | Namhyung Kim <> | Subject | Re: [PATCH 3/6] perf: Use sample_flags for branch stack |
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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().
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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