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 <a...@redhat.com>
---
include/linux/perf_event.h | 5 +++++
kernel/events/core.c | 3 ++-
2 files changed, 7 insertions(+), 1 deletions(-)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 40264b5..91342ac 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -973,6 +973,7 @@ 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 *
@@ -1168,6 +1169,10 @@ 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, int nmi,
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 6dd4819..f69cc9f 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1739,7 +1739,7 @@ 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
@@ -1752,6 +1752,7 @@ 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,
--
1.7.5.3
--
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