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perf: Use sample_flags for branch stack

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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>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220901130959.1285717-4-kan.liang@linux.intel.com
This commit is contained in:
Kan Liang 2022-09-01 06:09:56 -07:00 committed by Peter Zijlstra
parent 47a3aeb39e
commit a9a931e266
7 changed files with 18 additions and 8 deletions
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1
arch/powerpc/perf/core-book3s.c
View File

@ -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 &&

4
arch/x86/events/amd/core.c
View File

@ -929,8 +929,10 @@ static int amd_pmu_v2_handle_irq(struct pt_regs *regs)
if (!x86_perf_event_set_period(event))
continue;
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);

4
arch/x86/events/core.c
View File

@ -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);

4
arch/x86/events/intel/core.c
View File

@ -2995,8 +2995,10 @@ 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);

5
arch/x86/events/intel/ds.c
View File

@ -1640,8 +1640,10 @@ 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,
@ -1791,6 +1793,7 @@ 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;
}
}

4
include/linux/perf_event.h
View File

@ -1011,7 +1011,6 @@ 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;
@ -1021,6 +1020,8 @@ 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 {
@ -1061,7 +1062,6 @@ 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;

4
kernel/events/core.c
View File

@ -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);