diff options
| -rw-r--r-- | arch/x86/kernel/cpu/perf_counter.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c index 5afae13d8d59..6d30f603b62c 100644 --- a/arch/x86/kernel/cpu/perf_counter.c +++ b/arch/x86/kernel/cpu/perf_counter.c @@ -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); |