perf: export perf_event_refresh() to modules

KVM needs one-shot samples, since a PMC programmed to -X will fire after X
events and then again after 2^40 events (i.e. variable period).

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1309362157-6596-4-git-send-email-avi@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 7 insertions, 1 deletions

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 2a08cacb1628..3f2711ccf910 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -955,6 +955,7 @@ extern void perf_pmu_disable(struct pmu *pmu);
 extern void perf_pmu_enable(struct pmu *pmu);
 extern int perf_event_task_disable(void);
 extern int perf_event_task_enable(void);
+extern int perf_event_refresh(struct perf_event *event, int refresh);
 extern void perf_event_update_userpage(struct perf_event *event);
 extern int perf_event_release_kernel(struct perf_event *event);
 extern struct perf_event *
@@ -1149,6 +1150,10 @@ static inline void perf_event_delayed_put(struct task_struct *task)	{ }
 static inline void perf_event_print_debug(void)                         { }
 static inline int perf_event_task_disable(void)                         { return -EINVAL; }
 static inline int perf_event_task_enable(void)                          { return -EINVAL; }
+static inline int perf_event_refresh(struct perf_event *event, int refresh)
+{
+        return -EINVAL;
+}
 
 static inline void
 perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)     { }
diff --git a/kernel/events/core.c b/kernel/events/core.c
index ba8e0f4a20e6..0567e32d71aa 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1764,7 +1764,7 @@ out:
         raw_spin_unlock_irq(&ctx->lock);
 }
 
-static int perf_event_refresh(struct perf_event *event, int refresh)
+int perf_event_refresh(struct perf_event *event, int refresh)
 {
         /*
          * not supported on inherited events
@@ -1777,6 +1777,7 @@ static int perf_event_refresh(struct perf_event *event, int refresh)
 
         return 0;
 }
+EXPORT_SYMBOL_GPL(perf_event_refresh);
 
 static void ctx_sched_out(struct perf_event_context *ctx,
                           struct perf_cpu_context *cpuctx,