diff options
| author | Robert Richter <robert.richter@amd.com> | 2012-06-20 20:46:36 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2012-07-05 21:19:42 +0200 |
| commit | f285f92f7e4c9af20149130c8fd5027131b39b0e (patch) | |
| tree | 6b8f63bb0fab1898ca46859d8706a158288d3e2c /arch/x86/kernel/cpu/perf_event.c | |
| parent | b1dc3c4820428ac6216537416b2fcd140fdc52e5 (diff) | |
perf/x86: Improve debug output in check_hw_exists()
It might be of interest which perfctr msr failed.
Signed-off-by: Robert Richter <robert.richter@amd.com>
[ added hunk to avoid GCC warn ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1340217996-2254-5-git-send-email-robert.richter@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/cpu/perf_event.c')
| -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 7b4f1e871f7c..3eb88ebcec5a 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; } |