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authorStephane Eranian <eranian@google.com>2014-04-23 19:04:19 +0200
committerIngo Molnar <mingo@kernel.org>2014-04-24 08:12:41 +0200
commit9f7ff8931e3c5ddc8535476971ec9501e9555c05 (patch)
tree9d92eb11e72942ff41a3e603548041c7f3033c89 /arch/x86
parent89b90ee37a76a2bb05cc8ced30364b0de001f523 (diff)
downloadop-kernel-dev-9f7ff8931e3c5ddc8535476971ec9501e9555c05.zip
op-kernel-dev-9f7ff8931e3c5ddc8535476971ec9501e9555c05.tar.gz
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 <eranian@google.com> Acked-by: Borislav Petkov <bp@suse.de> Acked-by: Venkatesh Srinivas <venkateshs@google.com> Cc: peterz@infradead.org Cc: zheng.z.yan@intel.com Link: http://lkml.kernel.org/r/20140423170418.GA12767@quad Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/cpu/perf_event_intel_rapl.c3
1 files changed, 2 insertions, 1 deletions
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));
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