[PATCH 3/3] perf/arm_dsu: Allow standard cycles events
Robin Murphy
robin.murphy at arm.com
Mon Dec 15 05:05:00 PST 2025
Since we do not use the divide-by-64 option, there should be no
significant difference between the dedicated cycle counter and the
standard cycles event. Since using the latter on DSU-120 now has
the side-effect of allowing multiple cycles events to be scheduled
simultaneously (beneficial for multiple cycle-based metrics), there
seems little reason not to allow the same on older DSUs as well.
Signed-off-by: Robin Murphy <robin.murphy at arm.com>
---
drivers/perf/arm_dsu_pmu.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/perf/arm_dsu_pmu.c b/drivers/perf/arm_dsu_pmu.c
index 56c592f0dae3..32b0dd7c693b 100644
--- a/drivers/perf/arm_dsu_pmu.c
+++ b/drivers/perf/arm_dsu_pmu.c
@@ -284,9 +284,8 @@ static int dsu_pmu_get_event_idx(struct dsu_hw_events *hw_events,
unsigned long *used_mask = hw_events->used_mask;
if (evtype == DSU_PMU_EVT_CYCLES && dsu_pmu->has_pmccntr) {
- if (test_and_set_bit(DSU_PMU_IDX_CYCLE_COUNTER, used_mask))
- return -EAGAIN;
- return DSU_PMU_IDX_CYCLE_COUNTER;
+ if (!test_and_set_bit(DSU_PMU_IDX_CYCLE_COUNTER, used_mask))
+ return DSU_PMU_IDX_CYCLE_COUNTER;
}
idx = find_first_zero_bit(used_mask, dsu_pmu->num_counters);
--
2.39.2.101.g768bb238c484.dirty
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