perf: Pass last sampling period to perf_sample_data_init()
We always need to pass the last sample period to
perf_sample_data_init(), otherwise the event distribution will be
wrong. Thus, modifiyng the function interface with the required period
as argument. So basically a pattern like this:
perf_sample_data_init(&data, ~0ULL);
data.period = event->hw.last_period;
will now be like that:
perf_sample_data_init(&data, ~0ULL, event->hw.last_period);
Avoids unininitialized data.period and simplifies code.
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1333390758-10893-3-git-send-email-robert.richter@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/alpha/kernel/perf_event.c b/arch/alpha/kernel/perf_event.c
index 0dae252..d821b17 100644
--- a/arch/alpha/kernel/perf_event.c
+++ b/arch/alpha/kernel/perf_event.c
@@ -824,7 +824,6 @@
idx = la_ptr;
- perf_sample_data_init(&data, 0);
for (j = 0; j < cpuc->n_events; j++) {
if (cpuc->current_idx[j] == idx)
break;
@@ -848,7 +847,7 @@
hwc = &event->hw;
alpha_perf_event_update(event, hwc, idx, alpha_pmu->pmc_max_period[idx]+1);
- data.period = event->hw.last_period;
+ perf_sample_data_init(&data, 0, hwc->last_period);
if (alpha_perf_event_set_period(event, hwc, idx)) {
if (perf_event_overflow(event, &data, regs)) {