[PATCH 2/2] perf: Add perf sample data flag for br_stack

[Kan Liang]

Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
---
 arch/x86/events/intel/ds.c | 5 ++++-
 include/linux/perf_event.h | 5 +++--
 kernel/events/core.c       | 4 ++--
 3 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index a2c26eaeb0d9..27c440c13bfd 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -1692,8 +1692,10 @@ static void setup_pebs_fixed_sample_data(struct
perf_event *event,
 		data->flags |= PERF_SAMPLE_DATA_TIME;
 	}

-	if (has_branch_stack(event))
+	if (has_branch_stack(event)) {
 		data->br_stack = &cpuc->lbr_stack;
+		data->flags |= PERF_SAMPLE_DATA_BR_STACK;
+	}
 }

 static void adaptive_pebs_save_regs(struct pt_regs *regs,
@@ -1847,6 +1849,7 @@ 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->flags |= PERF_SAMPLE_DATA_BR_STACK;
 		}
 	}

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 33054bf31fc1..8c4a2913ec58 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1000,6 +1000,7 @@ extern u64 perf_event_read_value(struct perf_event
*event,
 				 u64 *enabled, u64 *running);

 #define PERF_SAMPLE_DATA_TIME		0x1
+#define PERF_SAMPLE_DATA_BR_STACK	0x2

 struct perf_sample_data {
 	/*
@@ -1008,7 +1009,6 @@ struct perf_sample_data {
 	 */
 	u64				addr;
 	struct perf_raw_record		*raw;
-	struct perf_branch_stack	*br_stack;
 	u64				period;
 	union perf_sample_weight	weight;
 	u64				txn;
@@ -1019,6 +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 {
@@ -1058,7 +1060,6 @@ static inline void perf_sample_data_init(struct
perf_sample_data *data,
 	/* remaining struct members initialized in perf_prepare_sample() */
 	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 057c197ae106..cd19ce85ef59 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7039,7 +7039,7 @@ void perf_output_sample(struct perf_output_handle
*handle,
 	}

 	if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
-		if (data->br_stack) {
+		if (data->flags & PERF_SAMPLE_DATA_BR_STACK) {
 			size_t size;

 			size = data->br_stack->nr
@@ -7339,7 +7339,7 @@ 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->flags & PERF_SAMPLE_DATA_BR_STACK) {
 			if (perf_sample_save_hw_index(event))
 				size += sizeof(u64);

-- 
2.35.1


Thanks,
Kan