diff options
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 7b4f1e871f7..3eb88ebcec5 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -178,7 +178,7 @@ static void release_pmc_hardware(void) {} static bool check_hw_exists(void) { - u64 val, val_new = 0; + u64 val, val_new = ~0; int i, reg, ret = 0; /* @@ -211,8 +211,9 @@ static bool check_hw_exists(void) * that don't trap on the MSR access and always return 0s. */ val = 0xabcdUL; - ret = wrmsrl_safe(x86_pmu_event_addr(0), val); - ret |= rdmsrl_safe(x86_pmu_event_addr(0), &val_new); + reg = x86_pmu_event_addr(0); + ret = wrmsrl_safe(reg, val); + ret |= rdmsrl_safe(reg, &val_new); if (ret || val != val_new) goto msr_fail; @@ -229,6 +230,7 @@ bios_fail: msr_fail: printk(KERN_CONT "Broken PMU hardware detected, using software events only.\n"); + printk(KERN_ERR "Failed to access perfctr msr (MSR %x is %Lx)\n", reg, val_new); return false; } |