Commit-ID: 15fde1101a1aed11958e0d86bc360f01866a74b1 Gitweb: http://git.kernel.org/tip/15fde1101a1aed11958e0d86bc360f01866a74b1 Author: Andi Kleen <[email protected]> AuthorDate: Fri, 27 Feb 2015 09:48:32 -0800 Committer: Ingo Molnar <[email protected]> CommitDate: Thu, 2 Apr 2015 17:33:17 +0200
perf/x86: Only dump PEBS register when PEBS has been detected Technically PEBS_ENABLED is only guaranteed to exist when we detected PEBS. So add a check for this to the PMU dump function. I don't think it can happen on a real CPU, but could in a VM. Signed-off-by: Andi Kleen <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/kernel/cpu/perf_event.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 9947372..689e357 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -1189,14 +1189,16 @@ void perf_event_print_debug(void) rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, status); rdmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, overflow); rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR_CTRL, fixed); - rdmsrl(MSR_IA32_PEBS_ENABLE, pebs); pr_info("\n"); pr_info("CPU#%d: ctrl: %016llx\n", cpu, ctrl); pr_info("CPU#%d: status: %016llx\n", cpu, status); pr_info("CPU#%d: overflow: %016llx\n", cpu, overflow); pr_info("CPU#%d: fixed: %016llx\n", cpu, fixed); - pr_info("CPU#%d: pebs: %016llx\n", cpu, pebs); + if (x86_pmu.pebs_constraints) { + rdmsrl(MSR_IA32_PEBS_ENABLE, pebs); + pr_info("CPU#%d: pebs: %016llx\n", cpu, pebs); + } if (x86_pmu.lbr_nr) { rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl); pr_info("CPU#%d: debugctl: %016llx\n", cpu, debugctl); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
