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| author | Andrew Murray <andrew.murray@arm.com> | 2019-04-09 20:22:10 +0100 |
|---|---|---|
| committer | Marc Zyngier <marc.zyngier@arm.com> | 2019-04-24 15:34:31 +0100 |
| commit | 21bb0ebf5d78c669ed887f30889f2d28cf6bf7db (patch) | |
| tree | cead3b66ba563216de2f225829cc4401d2665b5e /arch/arm64/kernel/perf_event.c | |
| parent | a243c16d18be130b17cf1064e9115de73bfdff5a (diff) | |
| download | linux-21bb0ebf5d78c669ed887f30889f2d28cf6bf7db.tar.bz2 | |
arm64: arm_pmu: Remove unnecessary isb instruction
The armv8pmu_enable_event_counter function issues an isb instruction
after enabling a pair of counters - this doesn't provide any value
and is inconsistent with the armv8pmu_disable_event_counter.
In any case armv8pmu_enable_event_counter is always called with the
PMU stopped. Starting the PMU with armv8pmu_start results in an isb
instruction being issued prior to writing to PMCR_EL0.
Let's remove the unnecessary isb instruction.
Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch/arm64/kernel/perf_event.c')
| -rw-r--r-- | arch/arm64/kernel/perf_event.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c index 4addb38bc250..cccf4fc86d67 100644 --- a/arch/arm64/kernel/perf_event.c +++ b/arch/arm64/kernel/perf_event.c @@ -533,7 +533,6 @@ static inline void armv8pmu_enable_event_counter(struct perf_event *event) armv8pmu_enable_counter(idx); if (armv8pmu_event_is_chained(event)) armv8pmu_enable_counter(idx - 1); - isb(); } static inline int armv8pmu_disable_counter(int idx) |