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perfcounters: fix non-intel-perfmon CPUs 

Do not write MSR_CORE_PERF_GLOBAL_CTRL on CPUs where it does not exist.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
hifive-unleashed-5.1
Ingo Molnar 2008-12-14 18:36:30 +01:00
parent e06c61a879
commit 2b9ff0db19
1 changed files with 10 additions and 0 deletions
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10
arch/x86/kernel/cpu/perf_counter.c
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@ -157,6 +157,9 @@ static int __hw_perf_counter_init(struct perf_counter *counter)
void hw_perf_enable_all(void)
{
if (unlikely(!perf_counters_initialized))
return;
wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, perf_counter_mask, 0);
}
@ -164,14 +167,21 @@ u64 hw_perf_save_disable(void)
{
u64 ctrl;
if (unlikely(!perf_counters_initialized))
return 0;
rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, ctrl);
wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, 0, 0);
return ctrl;
}
EXPORT_SYMBOL_GPL(hw_perf_save_disable);
void hw_perf_restore(u64 ctrl)
{
if (unlikely(!perf_counters_initialized))
return;
wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, ctrl, 0);
}
EXPORT_SYMBOL_GPL(hw_perf_restore);