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>

3 files changed, 4 insertions, 12 deletions

diff --git a/arch/arm/kernel/perf_event_v6.c b/arch/arm/kernel/perf_event_v6.c
index b78af0cc6ef3..ab627a740fa3 100644
--- a/arch/arm/kernel/perf_event_v6.c
+++ b/arch/arm/kernel/perf_event_v6.c
@@ -489,8 +489,6 @@ armv6pmu_handle_irq(int irq_num,
          */
         armv6_pmcr_write(pmcr);
 
-        perf_sample_data_init(&data, 0);
-
         cpuc = &__get_cpu_var(cpu_hw_events);
         for (idx = 0; idx < cpu_pmu->num_events; ++idx) {
                 struct perf_event *event = cpuc->events[idx];
@@ -509,7 +507,7 @@ armv6pmu_handle_irq(int irq_num,
 
                 hwc = &event->hw;
                 armpmu_event_update(event, hwc, idx);
-                data.period = event->hw.last_period;
+                perf_sample_data_init(&data, 0, hwc->last_period);
                 if (!armpmu_event_set_period(event, hwc, idx))
                         continue;
 
diff --git a/arch/arm/kernel/perf_event_v7.c b/arch/arm/kernel/perf_event_v7.c
index 00755d82e2f2..d3c536068162 100644
--- a/arch/arm/kernel/perf_event_v7.c
+++ b/arch/arm/kernel/perf_event_v7.c
@@ -1077,8 +1077,6 @@ static irqreturn_t armv7pmu_handle_irq(int irq_num, void *dev)
          */
         regs = get_irq_regs();
 
-        perf_sample_data_init(&data, 0);
-
         cpuc = &__get_cpu_var(cpu_hw_events);
         for (idx = 0; idx < cpu_pmu->num_events; ++idx) {
                 struct perf_event *event = cpuc->events[idx];
@@ -1097,7 +1095,7 @@ static irqreturn_t armv7pmu_handle_irq(int irq_num, void *dev)
 
                 hwc = &event->hw;
                 armpmu_event_update(event, hwc, idx);
-                data.period = event->hw.last_period;
+                perf_sample_data_init(&data, 0, hwc->last_period);
                 if (!armpmu_event_set_period(event, hwc, idx))
                         continue;
 
diff --git a/arch/arm/kernel/perf_event_xscale.c b/arch/arm/kernel/perf_event_xscale.c
index 71a21e6712f5..e34e7254e652 100644
--- a/arch/arm/kernel/perf_event_xscale.c
+++ b/arch/arm/kernel/perf_event_xscale.c
@@ -248,8 +248,6 @@ xscale1pmu_handle_irq(int irq_num, void *dev)
 
         regs = get_irq_regs();
 
-        perf_sample_data_init(&data, 0);
-
         cpuc = &__get_cpu_var(cpu_hw_events);
         for (idx = 0; idx < cpu_pmu->num_events; ++idx) {
                 struct perf_event *event = cpuc->events[idx];
@@ -263,7 +261,7 @@ xscale1pmu_handle_irq(int irq_num, void *dev)
 
                 hwc = &event->hw;
                 armpmu_event_update(event, hwc, idx);
-                data.period = event->hw.last_period;
+                perf_sample_data_init(&data, 0, hwc->last_period);
                 if (!armpmu_event_set_period(event, hwc, idx))
                         continue;
 
@@ -588,8 +586,6 @@ xscale2pmu_handle_irq(int irq_num, void *dev)
 
         regs = get_irq_regs();
 
-        perf_sample_data_init(&data, 0);
-
         cpuc = &__get_cpu_var(cpu_hw_events);
         for (idx = 0; idx < cpu_pmu->num_events; ++idx) {
                 struct perf_event *event = cpuc->events[idx];
@@ -603,7 +599,7 @@ xscale2pmu_handle_irq(int irq_num, void *dev)
 
                 hwc = &event->hw;
                 armpmu_event_update(event, hwc, idx);
-                data.period = event->hw.last_period;
+                perf_sample_data_init(&data, 0, hwc->last_period);
                 if (!armpmu_event_set_period(event, hwc, idx))
                         continue;