[PATCH v8 4/5] perf arm-spe: Don't set data source if it's not a memory operation

Ali Saidi
2022-05-04T18:49:15Z

From: Leo Yan <leo.yan@linaro.org>

Except memory load and store operations, Arm SPE records also can
support other operation types, bug when set the data source field the
current code assumes a record is a either load operation or store
operation, this leads to wrongly synthesize memory samples.

This patch strictly checks the record operation type, it only sets data
source only for the operation types ARM_SPE_LD and ARM_SPE_ST,
otherwise, returns zero for data source. Therefore, we can synthesize
memory samples only when data source is a non-zero value, the function
arm_spe__is_memory_event() is useless and removed.

Fixes: e55ed3423c1b ("perf arm-spe: Synthesize memory event")
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Ali Saidi <alisaidi@amazon.com>
Tested-by: Ali Saidi <alisaidi@amazon.com>
Reviewed-by: German Gomez <german.gomez@arm.com>
---
tools/perf/util/arm-spe.c | 22 ++++++++--------------
1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/tools/perf/util/arm-spe.c b/tools/perf/util/arm-spe.c
index d2b64e3f588b..e032efc03274 100644
--- a/tools/perf/util/arm-spe.c
+++ b/tools/perf/util/arm-spe.c
@@ -387,26 +387,16 @@ static int arm_spe__synth_instruction_sample(struct arm_spe_queue *speq,
return arm_spe_deliver_synth_event(spe, speq, event, &sample);
}

-#define SPE_MEM_TYPE (ARM_SPE_L1D_ACCESS | ARM_SPE_L1D_MISS | \
- ARM_SPE_LLC_ACCESS | ARM_SPE_LLC_MISS | \
- ARM_SPE_REMOTE_ACCESS)
-
-static bool arm_spe__is_memory_event(enum arm_spe_sample_type type)
-{
- if (type & SPE_MEM_TYPE)
- return true;
-
- return false;
-}
-
static u64 arm_spe__synth_data_source(const struct arm_spe_record *record)
{
union perf_mem_data_src data_src = { 0 };

if (record->op == ARM_SPE_LD)
data_src.mem_op = PERF_MEM_OP_LOAD;
- else
+ else if (record->op == ARM_SPE_ST)
data_src.mem_op = PERF_MEM_OP_STORE;
+ else
+ return 0;

if (record->type & (ARM_SPE_LLC_ACCESS | ARM_SPE_LLC_MISS)) {
data_src.mem_lvl = PERF_MEM_LVL_L3;
@@ -510,7 +500,11 @@ static int arm_spe_sample(struct arm_spe_queue *speq)
return err;
}

- if (spe->sample_memory && arm_spe__is_memory_event(record->type)) {
+ /*
+ * When data_src is zero it means the record is not a memory operation,
+ * skip to synthesize memory sample for this case.
+ */
+ if (spe->sample_memory && data_src) {
err = arm_spe__synth_mem_sample(speq, spe->memory_id, data_src);
if (err)
return err;
--
2.32.0