Commit-ID: 9f7ff8931e3c5ddc8535476971ec9501e9555c05 Gitweb: http://git.kernel.org/tip/9f7ff8931e3c5ddc8535476971ec9501e9555c05 Author: Stephane Eranian <eran...@google.com> AuthorDate: Wed, 23 Apr 2014 19:04:19 +0200 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Thu, 24 Apr 2014 08:12:41 +0200
perf/x86: Fix RAPL rdmsrl_safe() usage This patch fixes a bug introduced by: 24223657806a ("perf/x86/intel: Use rdmsrl_safe() when initializing RAPL PMU") The rdmsrl_safe() function returns 0 on success. The current code was failing to detect the RAPL PMU on real hardware (missing /sys/devices/power) because the return value of rdmsrl_safe() was misinterpreted. Signed-off-by: Stephane Eranian <eran...@google.com> Acked-by: Borislav Petkov <b...@suse.de> Acked-by: Venkatesh Srinivas <venkate...@google.com> Cc: pet...@infradead.org Cc: zheng.z....@intel.com Link: http://lkml.kernel.org/r/20140423170418.GA12767@quad Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/kernel/cpu/perf_event_intel_rapl.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/perf_event_intel_rapl.c b/arch/x86/kernel/cpu/perf_event_intel_rapl.c index 7c87424..619f769 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_rapl.c +++ b/arch/x86/kernel/cpu/perf_event_intel_rapl.c @@ -543,7 +543,8 @@ static int rapl_cpu_prepare(int cpu) if (phys_id < 0) return -1; - if (!rdmsrl_safe(MSR_RAPL_POWER_UNIT, &msr_rapl_power_unit_bits)) + /* protect rdmsrl() to handle virtualization */ + if (rdmsrl_safe(MSR_RAPL_POWER_UNIT, &msr_rapl_power_unit_bits)) return -1; pmu = kzalloc_node(sizeof(*pmu), GFP_KERNEL, cpu_to_node(cpu)); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/