lkml.org 
[lkml]   [2022]   [Aug]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 3/6] perf: Use sample_flags for branch stack
Date
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(-)

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
\
 
 \ /
  Last update: 2022-08-31 16:56    [W:0.147 / U:0.952 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site