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-rw-r--r--arch/x86/kernel/cpu/aperfmperf.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/arch/x86/kernel/cpu/aperfmperf.c b/arch/x86/kernel/cpu/aperfmperf.c
index 0ee83321a313..957813e0180d 100644
--- a/arch/x86/kernel/cpu/aperfmperf.c
+++ b/arch/x86/kernel/cpu/aperfmperf.c
@@ -42,10 +42,6 @@ static void aperfmperf_snapshot_khz(void *dummy)
s64 time_delta = ktime_ms_delta(now, s->time);
unsigned long flags;
- /* Don't bother re-computing within the cache threshold time. */
- if (time_delta < APERFMPERF_CACHE_THRESHOLD_MS)
- return;
-
local_irq_save(flags);
rdmsrl(MSR_IA32_APERF, aperf);
rdmsrl(MSR_IA32_MPERF, mperf);
@@ -74,6 +70,7 @@ static void aperfmperf_snapshot_khz(void *dummy)
unsigned int arch_freq_get_on_cpu(int cpu)
{
+ s64 time_delta;
unsigned int khz;
if (!cpu_khz)
@@ -82,6 +79,12 @@ unsigned int arch_freq_get_on_cpu(int cpu)
if (!static_cpu_has(X86_FEATURE_APERFMPERF))
return 0;
+ /* Don't bother re-computing within the cache threshold time. */
+ time_delta = ktime_ms_delta(ktime_get(), per_cpu(samples.time, cpu));
+ khz = per_cpu(samples.khz, cpu);
+ if (khz && time_delta < APERFMPERF_CACHE_THRESHOLD_MS)
+ return khz;
+
smp_call_function_single(cpu, aperfmperf_snapshot_khz, NULL, 1);
khz = per_cpu(samples.khz, cpu);
if (khz)
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