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| author | Yunhui Cui <cuiyunhui@bytedance.com> | 2025-08-04 10:51:10 +0800 |
|---|---|---|
| committer | Paul Walmsley <pjw@kernel.org> | 2025-09-18 19:28:13 -0600 |
| commit | 568a2fa10dd06bbd8160e3f8cce9483fabcb7121 (patch) | |
| tree | 3e72decc86753b40e9e40446eb4effeee53934f4 /drivers | |
| parent | selftests: riscv: Add README for RISC-V KSelfTest (diff) | |
| download | linux-568a2fa10dd06bbd8160e3f8cce9483fabcb7121.tar.gz linux-568a2fa10dd06bbd8160e3f8cce9483fabcb7121.zip | |
perf: riscv: skip empty batches in counter start
Avoid unnecessary SBI calls when starting non-overflowed counters
in pmu_sbi_start_ovf_ctrs_sbi() by checking ctr_start_mask.
Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20250804025110.11088-1-cuiyunhui@bytedance.com
Signed-off-by: Paul Walmsley <pjw@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/perf/riscv_pmu_sbi.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c index c18dbffa9834..3fc16bbab025 100644 --- a/drivers/perf/riscv_pmu_sbi.c +++ b/drivers/perf/riscv_pmu_sbi.c @@ -877,8 +877,10 @@ static inline void pmu_sbi_start_ovf_ctrs_sbi(struct cpu_hw_events *cpu_hw_evt, for (i = 0; i < BITS_TO_LONGS(RISCV_MAX_COUNTERS); i++) { ctr_start_mask = cpu_hw_evt->used_hw_ctrs[i] & ~ctr_ovf_mask; /* Start all the counters that did not overflow in a single shot */ - sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, i * BITS_PER_LONG, ctr_start_mask, - 0, 0, 0, 0); + if (ctr_start_mask) { + sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, i * BITS_PER_LONG, + ctr_start_mask, 0, 0, 0, 0); + } } /* Reinitialize and start all the counter that overflowed */ |