x86, perf: P4 PMU -- protect sensible procedures from preemption

[safe/jmp/linux-2.6] / arch / x86 / kernel / cpu / perf_event_p4.c

diff --git a/arch/x86/kernel/cpu/perf_event_p4.c b/arch/x86/kernel/cpu/perf_event_p4.c
index b1f532d..ca40180 100644 (file)
--- a/arch/x86/kernel/cpu/perf_event_p4.c
+++ b/arch/x86/kernel/cpu/perf_event_p4.c
@@ -421,7 +421,8 @@ static u64 p4_pmu_event_map(int hw_event)
 
 static int p4_hw_config(struct perf_event *event)
 {
-       int cpu = raw_smp_processor_id();
+       int cpu = get_cpu();
+       int rc = 0;
        u32 escr, cccr;
 
        /*
@@ -454,7 +455,10 @@ static int p4_hw_config(struct perf_event *event)
                         p4_config_pack_cccr(P4_CCCR_MASK_HT));
        }
 
-       return x86_setup_perfctr(event);
+       rc = x86_setup_perfctr(event);
+       put_cpu();
+
+       return rc;
 }
 
 static inline void p4_pmu_clear_cccr_ovf(struct hw_perf_event *hwc)