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perf: Pass last sampling period to perf_sample_data_init()
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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 <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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Robert Richter authored and Ingo Molnar committed May 9, 2012
1 parent c75841a commit fd0d000
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Showing 15 changed files with 25 additions and 43 deletions.
3 changes: 1 addition & 2 deletions arch/alpha/kernel/perf_event.c
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Original file line number Diff line number Diff line change
Expand Up @@ -824,7 +824,6 @@ static void alpha_perf_event_irq_handler(unsigned long la_ptr,

idx = la_ptr;

perf_sample_data_init(&data, 0);
for (j = 0; j < cpuc->n_events; j++) {
if (cpuc->current_idx[j] == idx)
break;
Expand All @@ -848,7 +847,7 @@ static void alpha_perf_event_irq_handler(unsigned long la_ptr,

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)) {
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4 changes: 1 addition & 3 deletions arch/arm/kernel/perf_event_v6.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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];
Expand All @@ -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;

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4 changes: 1 addition & 3 deletions arch/arm/kernel/perf_event_v7.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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];
Expand All @@ -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;

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8 changes: 2 additions & 6 deletions arch/arm/kernel/perf_event_xscale.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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];
Expand All @@ -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;

Expand Down Expand Up @@ -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];
Expand All @@ -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;

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2 changes: 1 addition & 1 deletion arch/mips/kernel/perf_event_mipsxx.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1325,7 +1325,7 @@ static int mipsxx_pmu_handle_shared_irq(void)

regs = get_irq_regs();

perf_sample_data_init(&data, 0);
perf_sample_data_init(&data, 0, 0);

switch (counters) {
#define HANDLE_COUNTER(n) \
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3 changes: 1 addition & 2 deletions arch/powerpc/perf/core-book3s.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1299,8 +1299,7 @@ static void record_and_restart(struct perf_event *event, unsigned long val,
if (record) {
struct perf_sample_data data;

perf_sample_data_init(&data, ~0ULL);
data.period = event->hw.last_period;
perf_sample_data_init(&data, ~0ULL, event->hw.last_period);

if (event->attr.sample_type & PERF_SAMPLE_ADDR)
perf_get_data_addr(regs, &data.addr);
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3 changes: 1 addition & 2 deletions arch/powerpc/perf/core-fsl-emb.c
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Original file line number Diff line number Diff line change
Expand Up @@ -613,8 +613,7 @@ static void record_and_restart(struct perf_event *event, unsigned long val,
if (record) {
struct perf_sample_data data;

perf_sample_data_init(&data, 0);
data.period = event->hw.last_period;
perf_sample_data_init(&data, 0, event->hw.last_period);

if (perf_event_overflow(event, &data, regs))
fsl_emb_pmu_stop(event, 0);
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4 changes: 1 addition & 3 deletions arch/sparc/kernel/perf_event.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1296,8 +1296,6 @@ static int __kprobes perf_event_nmi_handler(struct notifier_block *self,

regs = args->regs;

perf_sample_data_init(&data, 0);

cpuc = &__get_cpu_var(cpu_hw_events);

/* If the PMU has the TOE IRQ enable bits, we need to do a
Expand All @@ -1321,7 +1319,7 @@ static int __kprobes perf_event_nmi_handler(struct notifier_block *self,
if (val & (1ULL << 31))
continue;

data.period = event->hw.last_period;
perf_sample_data_init(&data, 0, hwc->last_period);
if (!sparc_perf_event_set_period(event, hwc, idx))
continue;

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4 changes: 1 addition & 3 deletions arch/x86/kernel/cpu/perf_event.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1183,8 +1183,6 @@ int x86_pmu_handle_irq(struct pt_regs *regs)
int idx, handled = 0;
u64 val;

perf_sample_data_init(&data, 0);

cpuc = &__get_cpu_var(cpu_hw_events);

/*
Expand Down Expand Up @@ -1219,7 +1217,7 @@ int x86_pmu_handle_irq(struct pt_regs *regs)
* event overflow
*/
handled++;
data.period = event->hw.last_period;
perf_sample_data_init(&data, 0, event->hw.last_period);

if (!x86_perf_event_set_period(event))
continue;
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3 changes: 1 addition & 2 deletions arch/x86/kernel/cpu/perf_event_amd_ibs.c
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Original file line number Diff line number Diff line change
Expand Up @@ -398,8 +398,7 @@ static int perf_ibs_handle_irq(struct perf_ibs *perf_ibs, struct pt_regs *iregs)
}

perf_ibs_event_update(perf_ibs, event, config);
perf_sample_data_init(&data, 0);
data.period = event->hw.last_period;
perf_sample_data_init(&data, 0, hwc->last_period);

if (event->attr.sample_type & PERF_SAMPLE_RAW) {
ibs_data.caps = ibs_caps;
Expand Down
4 changes: 1 addition & 3 deletions arch/x86/kernel/cpu/perf_event_intel.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1027,8 +1027,6 @@ static int intel_pmu_handle_irq(struct pt_regs *regs)
u64 status;
int handled;

perf_sample_data_init(&data, 0);

cpuc = &__get_cpu_var(cpu_hw_events);

/*
Expand Down Expand Up @@ -1082,7 +1080,7 @@ static int intel_pmu_handle_irq(struct pt_regs *regs)
if (!intel_pmu_save_and_restart(event))
continue;

data.period = event->hw.last_period;
perf_sample_data_init(&data, 0, event->hw.last_period);

if (has_branch_stack(event))
data.br_stack = &cpuc->lbr_stack;
Expand Down
6 changes: 2 additions & 4 deletions arch/x86/kernel/cpu/perf_event_intel_ds.c
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Original file line number Diff line number Diff line change
Expand Up @@ -316,8 +316,7 @@ int intel_pmu_drain_bts_buffer(void)

ds->bts_index = ds->bts_buffer_base;

perf_sample_data_init(&data, 0);
data.period = event->hw.last_period;
perf_sample_data_init(&data, 0, event->hw.last_period);
regs.ip = 0;

/*
Expand Down Expand Up @@ -564,8 +563,7 @@ static void __intel_pmu_pebs_event(struct perf_event *event,
if (!intel_pmu_save_and_restart(event))
return;

perf_sample_data_init(&data, 0);
data.period = event->hw.last_period;
perf_sample_data_init(&data, 0, event->hw.last_period);

/*
* We use the interrupt regs as a base because the PEBS record
Expand Down
6 changes: 3 additions & 3 deletions arch/x86/kernel/cpu/perf_event_p4.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1005,8 +1005,6 @@ static int p4_pmu_handle_irq(struct pt_regs *regs)
int idx, handled = 0;
u64 val;

perf_sample_data_init(&data, 0);

cpuc = &__get_cpu_var(cpu_hw_events);

for (idx = 0; idx < x86_pmu.num_counters; idx++) {
Expand Down Expand Up @@ -1034,10 +1032,12 @@ static int p4_pmu_handle_irq(struct pt_regs *regs)
handled += overflow;

/* event overflow for sure */
data.period = event->hw.last_period;
perf_sample_data_init(&data, 0, hwc->last_period);

if (!x86_perf_event_set_period(event))
continue;


if (perf_event_overflow(event, &data, regs))
x86_pmu_stop(event, 0);
}
Expand Down
5 changes: 4 additions & 1 deletion include/linux/perf_event.h
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Original file line number Diff line number Diff line change
Expand Up @@ -1132,11 +1132,14 @@ struct perf_sample_data {
struct perf_branch_stack *br_stack;
};

static inline void perf_sample_data_init(struct perf_sample_data *data, u64 addr)
static inline void perf_sample_data_init(struct perf_sample_data *data,
u64 addr, u64 period)
{
/* remaining struct members initialized in perf_prepare_sample() */
data->addr = addr;
data->raw = NULL;
data->br_stack = NULL;
data->period = period;
}

extern void perf_output_sample(struct perf_output_handle *handle,
Expand Down
9 changes: 4 additions & 5 deletions kernel/events/core.c
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Original file line number Diff line number Diff line change
Expand Up @@ -4957,7 +4957,7 @@ void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
if (rctx < 0)
return;

perf_sample_data_init(&data, addr);
perf_sample_data_init(&data, addr, 0);

do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs);

Expand Down Expand Up @@ -5215,7 +5215,7 @@ void perf_tp_event(u64 addr, u64 count, void *record, int entry_size,
.data = record,
};

perf_sample_data_init(&data, addr);
perf_sample_data_init(&data, addr, 0);
data.raw = &raw;

hlist_for_each_entry_rcu(event, node, head, hlist_entry) {
Expand Down Expand Up @@ -5318,7 +5318,7 @@ void perf_bp_event(struct perf_event *bp, void *data)
struct perf_sample_data sample;
struct pt_regs *regs = data;

perf_sample_data_init(&sample, bp->attr.bp_addr);
perf_sample_data_init(&sample, bp->attr.bp_addr, 0);

if (!bp->hw.state && !perf_exclude_event(bp, regs))
perf_swevent_event(bp, 1, &sample, regs);
Expand All @@ -5344,8 +5344,7 @@ static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer)

event->pmu->read(event);

perf_sample_data_init(&data, 0);
data.period = event->hw.last_period;
perf_sample_data_init(&data, 0, event->hw.last_period);
regs = get_irq_regs();

if (regs && !perf_exclude_event(event, regs)) {
Expand Down

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