When arch level event init is called, the event is not yet connected to
the PMU, thereby causing validate_group() to always do dummy work. On MIPS,
this is due to the following lines in validate_event() called by
validate_group():
if (event->pmu != &pmu || event->state <= PERF_EVENT_STATE_OFF)
return 1;
This patch fixes it.
Signed-off-by: Deng-Cheng Zhu <dczhu@xxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxxxxxxx>
Cc: David Daney <david.daney@xxxxxxxxxx>
---
arch/mips/kernel/perf_event_mipsxx.c | 17 +++++++++++++----
1 files changed, 13 insertions(+), 4 deletions(-)
diff --git a/arch/mips/kernel/perf_event_mipsxx.c b/arch/mips/kernel/perf_event_mipsxx.c
index 1f654ca..c804fdd 100644
--- a/arch/mips/kernel/perf_event_mipsxx.c
+++ b/arch/mips/kernel/perf_event_mipsxx.c
@@ -548,6 +548,7 @@ static int __hw_perf_event_init(struct perf_event *event)
struct perf_event_attr *attr = &event->attr;
struct hw_perf_event *hwc = &event->hw;
const struct mips_perf_event *pev;
+ struct pmu *tmp;
int err;
/* Returning MIPS event descriptor for generic perf event. */
@@ -611,11 +612,19 @@ static int __hw_perf_event_init(struct perf_event *event)
}
err = 0;
- if (event->group_leader != event) {
+
+ /*
+ * we temporarily connect event to its pmu such that
+ * validate_event() in validate_group() can classify
+ * it as a MIPS event by passing (event->pmu == &pmu).
+ */
+ tmp = event->pmu;
+ event->pmu = &pmu;
+
+ if (event->group_leader != event)
err = validate_group(event);
- if (err)
- return -EINVAL;
- }
+
+ event->pmu = tmp;
event->destroy = hw_perf_event_destroy;
--
1.7.1
