[v3 2/5] RISC-V: Update user page mapping only once during start
Atish Patra
atishp at rivosinc.com
Mon Jul 11 10:46:29 PDT 2022
Currently, riscv_pmu_event_set_period updates the userpage mapping.
However, the caller of riscv_pmu_event_set_period should update
the userpage mapping because the counter can not be updated/started
from set_period function in counter overflow path.
Invoke the perf_event_update_userpage at the caller so that it
doesn't get invoked twice during counter start path.
Fixes: f5bfa23f576f ("RISC-V: Add a perf core library for pmu drivers")
Reviewed-by: Anup Patel <anup at brainfault.org>
Signed-off-by: Atish Patra <atishp at rivosinc.com>
---
drivers/perf/riscv_pmu.c | 1 -
drivers/perf/riscv_pmu_sbi.c | 1 +
2 files changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/perf/riscv_pmu.c b/drivers/perf/riscv_pmu.c
index b2b8d2074ed0..130b9f1a40e0 100644
--- a/drivers/perf/riscv_pmu.c
+++ b/drivers/perf/riscv_pmu.c
@@ -170,7 +170,6 @@ int riscv_pmu_event_set_period(struct perf_event *event)
left = (max_period >> 1);
local64_set(&hwc->prev_count, (u64)-left);
- perf_event_update_userpage(event);
return overflow;
}
diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c
index 0cb694b794ae..3735337a4cfb 100644
--- a/drivers/perf/riscv_pmu_sbi.c
+++ b/drivers/perf/riscv_pmu_sbi.c
@@ -532,6 +532,7 @@ static inline void pmu_sbi_start_overflow_mask(struct riscv_pmu *pmu,
sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, idx, 1,
flag, init_val, 0, 0);
#endif
+ perf_event_update_userpage(event);
}
ctr_ovf_mask = ctr_ovf_mask >> 1;
idx++;
--
2.25.1
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