perfcounters: consolidate global-disable codepaths

Impact: cleanup

Simplify global disable handling.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 6 insertions, 17 deletions

diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c
index 919ec46679b2..6a93d1f04d97 100644
--- a/arch/x86/kernel/cpu/perf_counter.c
+++ b/arch/x86/kernel/cpu/perf_counter.c
@@ -33,7 +33,6 @@ static u32 perf_counter_mask __read_mostly;
 struct cpu_hw_counters {
         struct perf_counter     *counters[MAX_HW_COUNTERS];
         unsigned long           used[BITS_TO_LONGS(MAX_HW_COUNTERS)];
-        int                     enable_all;
 };
 
 /*
@@ -115,24 +114,13 @@ int hw_perf_counter_init(struct perf_counter *counter, s32 hw_event_type)
         return 0;
 }
 
-static void __hw_perf_enable_all(void)
-{
-        wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, perf_counter_mask, 0);
-}
-
 void hw_perf_enable_all(void)
 {
-        struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters);
-
-        cpuc->enable_all = 1;
-        __hw_perf_enable_all();
+        wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, perf_counter_mask, 0);
 }
 
 void hw_perf_disable_all(void)
 {
-        struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters);
-
-        cpuc->enable_all = 0;
         wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, 0, 0);
 }
 
@@ -385,8 +373,10 @@ perf_handle_group(struct perf_counter *leader, u64 *status, u64 *overflown)
 static void __smp_perf_counter_interrupt(struct pt_regs *regs, int nmi)
 {
         int bit, cpu = smp_processor_id();
+        u64 ack, status, saved_global;
         struct cpu_hw_counters *cpuc;
-        u64 ack, status;
+
+        rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, saved_global);
 
         /* Disable counters globally */
         wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, 0, 0);
@@ -445,10 +435,9 @@ again:
                 goto again;
 out:
         /*
-         * Do not reenable when global enable is off:
+         * Restore - do not reenable when global enable is off:
          */
-        if (cpuc->enable_all)
-                __hw_perf_enable_all();
+        wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, saved_global, 0);
 }
 
 void smp_perf_counter_interrupt(struct pt_regs *regs)