[PATCH] drivers/perf: riscv: Disable PERF_SAMPLE_BRANCH_* while not supported

Pu Lehui pulehui at huaweicloud.com
Tue Mar 5 07:52:23 PST 2024


From: Pu Lehui <pulehui at huawei.com>

RISC-V perf does not yet support branch sampling. Two riscv bpf
testcases get_branch_snapshot and perf_branches/perf_branches_hw failed
due to not disabling such sampling.

Signed-off-by: Pu Lehui <pulehui at huawei.com>
---
 drivers/perf/riscv_pmu.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/perf/riscv_pmu.c b/drivers/perf/riscv_pmu.c
index c78a6fd6c57f..bc42cb95a97c 100644
--- a/drivers/perf/riscv_pmu.c
+++ b/drivers/perf/riscv_pmu.c
@@ -313,6 +313,10 @@ static int riscv_pmu_event_init(struct perf_event *event)
 	u64 event_config = 0;
 	uint64_t cmask;
 
+	/* does not support taken branch sampling */
+	if (has_branch_stack(event))
+		return -EOPNOTSUPP;
+
 	hwc->flags = 0;
 	mapped_event = rvpmu->event_map(event, &event_config);
 	if (mapped_event < 0) {
-- 
2.34.1




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