perf: Rework the PMU methods
Replace pmu::{enable,disable,start,stop,unthrottle} with
pmu::{add,del,start,stop}, all of which take a flags argument.
The new interface extends the capability to stop a counter while
keeping it scheduled on the PMU. We replace the throttled state with
the generic stopped state.
This also allows us to efficiently stop/start counters over certain
code paths (like IRQ handlers).
It also allows scheduling a counter without it starting, allowing for
a generic frozen state (useful for rotating stopped counters).
The stopped state is implemented in two different ways, depending on
how the architecture implemented the throttled state:
1) We disable the counter:
a) the pmu has per-counter enable bits, we flip that
b) we program a NOP event, preserving the counter state
2) We store the counter state and ignore all read/overflow events
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: paulus <paulus@samba.org>
Cc: stephane eranian <eranian@googlemail.com>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Lin Ming <ming.m.lin@intel.com>
Cc: Yanmin <yanmin_zhang@linux.intel.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: David Miller <davem@davemloft.net>
Cc: Michael Cree <mcree@orcon.net.nz>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/alpha/kernel/perf_event.c b/arch/alpha/kernel/perf_event.c
index 3e26073..380ef02 100644
--- a/arch/alpha/kernel/perf_event.c
+++ b/arch/alpha/kernel/perf_event.c
@@ -307,7 +307,7 @@
new_raw_count) != prev_raw_count)
goto again;
- delta = (new_raw_count - (prev_raw_count & alpha_pmu->pmc_count_mask[idx])) + ovf;
+ delta = (new_raw_count - (prev_raw_count & alpha_pmu->pmc_count_mask[idx])) + ovf;
/* It is possible on very rare occasions that the PMC has overflowed
* but the interrupt is yet to come. Detect and fix this situation.
@@ -402,14 +402,13 @@
struct hw_perf_event *hwc = &pe->hw;
int idx = hwc->idx;
- if (cpuc->current_idx[j] != PMC_NO_INDEX) {
- cpuc->idx_mask |= (1<<cpuc->current_idx[j]);
- continue;
+ if (cpuc->current_idx[j] == PMC_NO_INDEX) {
+ alpha_perf_event_set_period(pe, hwc, idx);
+ cpuc->current_idx[j] = idx;
}
- alpha_perf_event_set_period(pe, hwc, idx);
- cpuc->current_idx[j] = idx;
- cpuc->idx_mask |= (1<<cpuc->current_idx[j]);
+ if (!(hwc->state & PERF_HES_STOPPED))
+ cpuc->idx_mask |= (1<<cpuc->current_idx[j]);
}
cpuc->config = cpuc->event[0]->hw.config_base;
}
@@ -420,7 +419,7 @@
* - this function is called from outside this module via the pmu struct
* returned from perf event initialisation.
*/
-static int alpha_pmu_enable(struct perf_event *event)
+static int alpha_pmu_add(struct perf_event *event, int flags)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
int n0;
@@ -455,6 +454,10 @@
}
}
+ hwc->state = PERF_HES_UPTODATE;
+ if (!(flags & PERF_EF_START))
+ hwc->state |= PERF_HES_STOPPED;
+
local_irq_restore(flags);
perf_pmu_enable(event->pmu);
@@ -467,7 +470,7 @@
* - this function is called from outside this module via the pmu struct
* returned from perf event initialisation.
*/
-static void alpha_pmu_disable(struct perf_event *event)
+static void alpha_pmu_del(struct perf_event *event, int flags)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
struct hw_perf_event *hwc = &event->hw;
@@ -514,13 +517,44 @@
}
-static void alpha_pmu_unthrottle(struct perf_event *event)
+static void alpha_pmu_stop(struct perf_event *event, int flags)
{
struct hw_perf_event *hwc = &event->hw;
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+ if (!(hwc->state & PERF_HES_STOPPED)) {
+ cpuc->idx_mask &= !(1UL<<hwc->idx);
+ hwc->state |= PERF_HES_STOPPED;
+ }
+
+ if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
+ alpha_perf_event_update(event, hwc, hwc->idx, 0);
+ hwc->state |= PERF_HES_UPTODATE;
+ }
+
+ if (cpuc->enabled)
+ wrperfmon(PERFMON_CMD_ENABLE, (1UL<<hwc->idx));
+}
+
+
+static void alpha_pmu_start(struct perf_event *event, int flags)
+{
+ struct hw_perf_event *hwc = &event->hw;
+ struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+
+ if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
+ return;
+
+ if (flags & PERF_EF_RELOAD) {
+ WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
+ alpha_perf_event_set_period(event, hwc, hwc->idx);
+ }
+
+ hwc->state = 0;
+
cpuc->idx_mask |= 1UL<<hwc->idx;
- wrperfmon(PERFMON_CMD_ENABLE, (1UL<<hwc->idx));
+ if (cpuc->enabled)
+ wrperfmon(PERFMON_CMD_ENABLE, (1UL<<hwc->idx));
}
@@ -671,7 +705,7 @@
/*
* Main entry point - enable HW performance counters.
*/
-static void alpha_pmu_pmu_enable(struct pmu *pmu)
+static void alpha_pmu_enable(struct pmu *pmu)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
@@ -697,7 +731,7 @@
* Main entry point - disable HW performance counters.
*/
-static void alpha_pmu_pmu_disable(struct pmu *pmu)
+static void alpha_pmu_disable(struct pmu *pmu)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
@@ -711,13 +745,14 @@
}
static struct pmu pmu = {
- .pmu_enable = alpha_pmu_pmu_enable,
- .pmu_disable = alpha_pmu_pmu_disable,
+ .pmu_enable = alpha_pmu_enable,
+ .pmu_disable = alpha_pmu_disable,
.event_init = alpha_pmu_event_init,
- .enable = alpha_pmu_enable,
- .disable = alpha_pmu_disable,
+ .add = alpha_pmu_add,
+ .del = alpha_pmu_del,
+ .start = alpha_pmu_start,
+ .stop = alpha_pmu_stop,
.read = alpha_pmu_read,
- .unthrottle = alpha_pmu_unthrottle,
};
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index 3343f3f..448cfa6 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -221,27 +221,6 @@
}
static void
-armpmu_disable(struct perf_event *event)
-{
- struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
- struct hw_perf_event *hwc = &event->hw;
- int idx = hwc->idx;
-
- WARN_ON(idx < 0);
-
- clear_bit(idx, cpuc->active_mask);
- armpmu->disable(hwc, idx);
-
- barrier();
-
- armpmu_event_update(event, hwc, idx);
- cpuc->events[idx] = NULL;
- clear_bit(idx, cpuc->used_mask);
-
- perf_event_update_userpage(event);
-}
-
-static void
armpmu_read(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
@@ -254,13 +233,44 @@
}
static void
-armpmu_unthrottle(struct perf_event *event)
+armpmu_stop(struct perf_event *event, int flags)
{
struct hw_perf_event *hwc = &event->hw;
+ if (!armpmu)
+ return;
+
+ /*
+ * ARM pmu always has to update the counter, so ignore
+ * PERF_EF_UPDATE, see comments in armpmu_start().
+ */
+ if (!(hwc->state & PERF_HES_STOPPED)) {
+ armpmu->disable(hwc, hwc->idx);
+ barrier(); /* why? */
+ armpmu_event_update(event, hwc, hwc->idx);
+ hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
+ }
+}
+
+static void
+armpmu_start(struct perf_event *event, int flags)
+{
+ struct hw_perf_event *hwc = &event->hw;
+
+ if (!armpmu)
+ return;
+
+ /*
+ * ARM pmu always has to reprogram the period, so ignore
+ * PERF_EF_RELOAD, see the comment below.
+ */
+ if (flags & PERF_EF_RELOAD)
+ WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
+
+ hwc->state = 0;
/*
* Set the period again. Some counters can't be stopped, so when we
- * were throttled we simply disabled the IRQ source and the counter
+ * were stopped we simply disabled the IRQ source and the counter
* may have been left counting. If we don't do this step then we may
* get an interrupt too soon or *way* too late if the overflow has
* happened since disabling.
@@ -269,8 +279,25 @@
armpmu->enable(hwc, hwc->idx);
}
+static void
+armpmu_del(struct perf_event *event, int flags)
+{
+ struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+ struct hw_perf_event *hwc = &event->hw;
+ int idx = hwc->idx;
+
+ WARN_ON(idx < 0);
+
+ clear_bit(idx, cpuc->active_mask);
+ armpmu_stop(event, PERF_EF_UPDATE);
+ cpuc->events[idx] = NULL;
+ clear_bit(idx, cpuc->used_mask);
+
+ perf_event_update_userpage(event);
+}
+
static int
-armpmu_enable(struct perf_event *event)
+armpmu_add(struct perf_event *event, int flags)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
struct hw_perf_event *hwc = &event->hw;
@@ -295,11 +322,9 @@
cpuc->events[idx] = event;
set_bit(idx, cpuc->active_mask);
- /* Set the period for the event. */
- armpmu_event_set_period(event, hwc, idx);
-
- /* Enable the event. */
- armpmu->enable(hwc, idx);
+ hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
+ if (flags & PERF_EF_START)
+ armpmu_start(event, PERF_EF_RELOAD);
/* Propagate our changes to the userspace mapping. */
perf_event_update_userpage(event);
@@ -534,7 +559,7 @@
return err;
}
-static void armpmu_pmu_enable(struct pmu *pmu)
+static void armpmu_enable(struct pmu *pmu)
{
/* Enable all of the perf events on hardware. */
int idx;
@@ -555,20 +580,21 @@
armpmu->start();
}
-static void armpmu_pmu_disable(struct pmu *pmu)
+static void armpmu_disable(struct pmu *pmu)
{
if (armpmu)
armpmu->stop();
}
static struct pmu pmu = {
- .pmu_enable = armpmu_pmu_enable,
- .pmu_disable= armpmu_pmu_disable,
- .event_init = armpmu_event_init,
- .enable = armpmu_enable,
- .disable = armpmu_disable,
- .unthrottle = armpmu_unthrottle,
- .read = armpmu_read,
+ .pmu_enable = armpmu_enable,
+ .pmu_disable = armpmu_disable,
+ .event_init = armpmu_event_init,
+ .add = armpmu_add,
+ .del = armpmu_del,
+ .start = armpmu_start,
+ .stop = armpmu_stop,
+ .read = armpmu_read,
};
/*
diff --git a/arch/powerpc/kernel/perf_event.c b/arch/powerpc/kernel/perf_event.c
index deb84bb..9cb4924 100644
--- a/arch/powerpc/kernel/perf_event.c
+++ b/arch/powerpc/kernel/perf_event.c
@@ -402,6 +402,9 @@
{
s64 val, delta, prev;
+ if (event->hw.state & PERF_HES_STOPPED)
+ return;
+
if (!event->hw.idx)
return;
/*
@@ -517,7 +520,7 @@
* Disable all events to prevent PMU interrupts and to allow
* events to be added or removed.
*/
-static void power_pmu_pmu_disable(struct pmu *pmu)
+static void power_pmu_disable(struct pmu *pmu)
{
struct cpu_hw_events *cpuhw;
unsigned long flags;
@@ -565,7 +568,7 @@
* If we were previously disabled and events were added, then
* put the new config on the PMU.
*/
-static void power_pmu_pmu_enable(struct pmu *pmu)
+static void power_pmu_enable(struct pmu *pmu)
{
struct perf_event *event;
struct cpu_hw_events *cpuhw;
@@ -672,6 +675,8 @@
}
local64_set(&event->hw.prev_count, val);
event->hw.idx = idx;
+ if (event->hw.state & PERF_HES_STOPPED)
+ val = 0;
write_pmc(idx, val);
perf_event_update_userpage(event);
}
@@ -727,7 +732,7 @@
* re-enable the PMU in order to get hw_perf_enable to do the
* actual work of reconfiguring the PMU.
*/
-static int power_pmu_enable(struct perf_event *event)
+static int power_pmu_add(struct perf_event *event, int ef_flags)
{
struct cpu_hw_events *cpuhw;
unsigned long flags;
@@ -749,6 +754,9 @@
cpuhw->events[n0] = event->hw.config;
cpuhw->flags[n0] = event->hw.event_base;
+ if (!(ef_flags & PERF_EF_START))
+ event->hw.state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
+
/*
* If group events scheduling transaction was started,
* skip the schedulability test here, it will be peformed
@@ -777,7 +785,7 @@
/*
* Remove a event from the PMU.
*/
-static void power_pmu_disable(struct perf_event *event)
+static void power_pmu_del(struct perf_event *event, int ef_flags)
{
struct cpu_hw_events *cpuhw;
long i;
@@ -826,27 +834,53 @@
}
/*
- * Re-enable interrupts on a event after they were throttled
- * because they were coming too fast.
+ * POWER-PMU does not support disabling individual counters, hence
+ * program their cycle counter to their max value and ignore the interrupts.
*/
-static void power_pmu_unthrottle(struct perf_event *event)
+
+static void power_pmu_start(struct perf_event *event, int ef_flags)
{
- s64 val, left;
+ unsigned long flags;
+ s64 left;
+
+ if (!event->hw.idx || !event->hw.sample_period)
+ return;
+
+ if (!(event->hw.state & PERF_HES_STOPPED))
+ return;
+
+ if (ef_flags & PERF_EF_RELOAD)
+ WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
+
+ local_irq_save(flags);
+ perf_pmu_disable(event->pmu);
+
+ event->hw.state = 0;
+ left = local64_read(&event->hw.period_left);
+ write_pmc(event->hw.idx, left);
+
+ perf_event_update_userpage(event);
+ perf_pmu_enable(event->pmu);
+ local_irq_restore(flags);
+}
+
+static void power_pmu_stop(struct perf_event *event, int ef_flags)
+{
unsigned long flags;
if (!event->hw.idx || !event->hw.sample_period)
return;
+
+ if (event->hw.state & PERF_HES_STOPPED)
+ return;
+
local_irq_save(flags);
perf_pmu_disable(event->pmu);
+
power_pmu_read(event);
- left = event->hw.sample_period;
- event->hw.last_period = left;
- val = 0;
- if (left < 0x80000000L)
- val = 0x80000000L - left;
- write_pmc(event->hw.idx, val);
- local64_set(&event->hw.prev_count, val);
- local64_set(&event->hw.period_left, left);
+ event->hw.state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
+ write_pmc(event->hw.idx, 0);
+
perf_event_update_userpage(event);
perf_pmu_enable(event->pmu);
local_irq_restore(flags);
@@ -1131,13 +1165,14 @@
}
struct pmu power_pmu = {
- .pmu_enable = power_pmu_pmu_enable,
- .pmu_disable = power_pmu_pmu_disable,
+ .pmu_enable = power_pmu_enable,
+ .pmu_disable = power_pmu_disable,
.event_init = power_pmu_event_init,
- .enable = power_pmu_enable,
- .disable = power_pmu_disable,
+ .add = power_pmu_add,
+ .del = power_pmu_del,
+ .start = power_pmu_start,
+ .stop = power_pmu_stop,
.read = power_pmu_read,
- .unthrottle = power_pmu_unthrottle,
.start_txn = power_pmu_start_txn,
.cancel_txn = power_pmu_cancel_txn,
.commit_txn = power_pmu_commit_txn,
@@ -1155,6 +1190,11 @@
s64 prev, delta, left;
int record = 0;
+ if (event->hw.state & PERF_HES_STOPPED) {
+ write_pmc(event->hw.idx, 0);
+ return;
+ }
+
/* we don't have to worry about interrupts here */
prev = local64_read(&event->hw.prev_count);
delta = (val - prev) & 0xfffffffful;
@@ -1177,6 +1217,11 @@
val = 0x80000000LL - left;
}
+ write_pmc(event->hw.idx, val);
+ local64_set(&event->hw.prev_count, val);
+ local64_set(&event->hw.period_left, left);
+ perf_event_update_userpage(event);
+
/*
* Finally record data if requested.
*/
@@ -1189,23 +1234,9 @@
if (event->attr.sample_type & PERF_SAMPLE_ADDR)
perf_get_data_addr(regs, &data.addr);
- if (perf_event_overflow(event, nmi, &data, regs)) {
- /*
- * Interrupts are coming too fast - throttle them
- * by setting the event to 0, so it will be
- * at least 2^30 cycles until the next interrupt
- * (assuming each event counts at most 2 counts
- * per cycle).
- */
- val = 0;
- left = ~0ULL >> 1;
- }
+ if (perf_event_overflow(event, nmi, &data, regs))
+ power_pmu_stop(event, 0);
}
-
- write_pmc(event->hw.idx, val);
- local64_set(&event->hw.prev_count, val);
- local64_set(&event->hw.period_left, left);
- perf_event_update_userpage(event);
}
/*
diff --git a/arch/powerpc/kernel/perf_event_fsl_emb.c b/arch/powerpc/kernel/perf_event_fsl_emb.c
index 84b1974..7ecca59 100644
--- a/arch/powerpc/kernel/perf_event_fsl_emb.c
+++ b/arch/powerpc/kernel/perf_event_fsl_emb.c
@@ -156,6 +156,9 @@
{
s64 val, delta, prev;
+ if (event->hw.state & PERF_HES_STOPPED)
+ return;
+
/*
* Performance monitor interrupts come even when interrupts
* are soft-disabled, as long as interrupts are hard-enabled.
@@ -177,7 +180,7 @@
* Disable all events to prevent PMU interrupts and to allow
* events to be added or removed.
*/
-static void fsl_emb_pmu_pmu_disable(struct pmu *pmu)
+static void fsl_emb_pmu_disable(struct pmu *pmu)
{
struct cpu_hw_events *cpuhw;
unsigned long flags;
@@ -216,7 +219,7 @@
* If we were previously disabled and events were added, then
* put the new config on the PMU.
*/
-static void fsl_emb_pmu_pmu_enable(struct pmu *pmu)
+static void fsl_emb_pmu_enable(struct pmu *pmu)
{
struct cpu_hw_events *cpuhw;
unsigned long flags;
@@ -263,7 +266,7 @@
}
/* context locked on entry */
-static int fsl_emb_pmu_enable(struct perf_event *event)
+static int fsl_emb_pmu_add(struct perf_event *event, int flags)
{
struct cpu_hw_events *cpuhw;
int ret = -EAGAIN;
@@ -302,6 +305,12 @@
val = 0x80000000L - left;
}
local64_set(&event->hw.prev_count, val);
+
+ if (!(flags & PERF_EF_START)) {
+ event->hw.state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
+ val = 0;
+ }
+
write_pmc(i, val);
perf_event_update_userpage(event);
@@ -316,7 +325,7 @@
}
/* context locked on entry */
-static void fsl_emb_pmu_disable(struct perf_event *event)
+static void fsl_emb_pmu_del(struct perf_event *event, int flags)
{
struct cpu_hw_events *cpuhw;
int i = event->hw.idx;
@@ -353,30 +362,49 @@
put_cpu_var(cpu_hw_events);
}
-/*
- * Re-enable interrupts on a event after they were throttled
- * because they were coming too fast.
- *
- * Context is locked on entry, but perf is not disabled.
- */
-static void fsl_emb_pmu_unthrottle(struct perf_event *event)
+static void fsl_emb_pmu_start(struct perf_event *event, int ef_flags)
{
- s64 val, left;
+ unsigned long flags;
+ s64 left;
+
+ if (event->hw.idx < 0 || !event->hw.sample_period)
+ return;
+
+ if (!(event->hw.state & PERF_HES_STOPPED))
+ return;
+
+ if (ef_flags & PERF_EF_RELOAD)
+ WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
+
+ local_irq_save(flags);
+ perf_pmu_disable(event->pmu);
+
+ event->hw.state = 0;
+ left = local64_read(&event->hw.period_left);
+ write_pmc(event->hw.idx, left);
+
+ perf_event_update_userpage(event);
+ perf_pmu_enable(event->pmu);
+ local_irq_restore(flags);
+}
+
+static void fsl_emb_pmu_stop(struct perf_event *event, int ef_flags)
+{
unsigned long flags;
if (event->hw.idx < 0 || !event->hw.sample_period)
return;
+
+ if (event->hw.state & PERF_HES_STOPPED)
+ return;
+
local_irq_save(flags);
perf_pmu_disable(event->pmu);
+
fsl_emb_pmu_read(event);
- left = event->hw.sample_period;
- event->hw.last_period = left;
- val = 0;
- if (left < 0x80000000L)
- val = 0x80000000L - left;
- write_pmc(event->hw.idx, val);
- local64_set(&event->hw.prev_count, val);
- local64_set(&event->hw.period_left, left);
+ event->hw.state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
+ write_pmc(event->hw.idx, 0);
+
perf_event_update_userpage(event);
perf_pmu_enable(event->pmu);
local_irq_restore(flags);
@@ -524,13 +552,14 @@
}
static struct pmu fsl_emb_pmu = {
- .pmu_enable = fsl_emb_pmu_pmu_enable,
- .pmu_disable = fsl_emb_pmu_pmu_disable,
+ .pmu_enable = fsl_emb_pmu_enable,
+ .pmu_disable = fsl_emb_pmu_disable,
.event_init = fsl_emb_pmu_event_init,
- .enable = fsl_emb_pmu_enable,
- .disable = fsl_emb_pmu_disable,
+ .add = fsl_emb_pmu_add,
+ .del = fsl_emb_pmu_del,
+ .start = fsl_emb_pmu_start,
+ .stop = fsl_emb_pmu_stop,
.read = fsl_emb_pmu_read,
- .unthrottle = fsl_emb_pmu_unthrottle,
};
/*
@@ -545,6 +574,11 @@
s64 prev, delta, left;
int record = 0;
+ if (event->hw.state & PERF_HES_STOPPED) {
+ write_pmc(event->hw.idx, 0);
+ return;
+ }
+
/* we don't have to worry about interrupts here */
prev = local64_read(&event->hw.prev_count);
delta = (val - prev) & 0xfffffffful;
@@ -567,6 +601,11 @@
val = 0x80000000LL - left;
}
+ write_pmc(event->hw.idx, val);
+ local64_set(&event->hw.prev_count, val);
+ local64_set(&event->hw.period_left, left);
+ perf_event_update_userpage(event);
+
/*
* Finally record data if requested.
*/
@@ -576,23 +615,9 @@
perf_sample_data_init(&data, 0);
data.period = event->hw.last_period;
- if (perf_event_overflow(event, nmi, &data, regs)) {
- /*
- * Interrupts are coming too fast - throttle them
- * by setting the event to 0, so it will be
- * at least 2^30 cycles until the next interrupt
- * (assuming each event counts at most 2 counts
- * per cycle).
- */
- val = 0;
- left = ~0ULL >> 1;
- }
+ if (perf_event_overflow(event, nmi, &data, regs))
+ fsl_emb_pmu_stop(event, 0);
}
-
- write_pmc(event->hw.idx, val);
- local64_set(&event->hw.prev_count, val);
- local64_set(&event->hw.period_left, left);
- perf_event_update_userpage(event);
}
static void perf_event_interrupt(struct pt_regs *regs)
diff --git a/arch/sh/kernel/perf_event.c b/arch/sh/kernel/perf_event.c
index 4bbe190..cf39c48 100644
--- a/arch/sh/kernel/perf_event.c
+++ b/arch/sh/kernel/perf_event.c
@@ -206,26 +206,52 @@
local64_add(delta, &event->count);
}
-static void sh_pmu_disable(struct perf_event *event)
+static void sh_pmu_stop(struct perf_event *event, int flags)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
struct hw_perf_event *hwc = &event->hw;
int idx = hwc->idx;
- clear_bit(idx, cpuc->active_mask);
- sh_pmu->disable(hwc, idx);
+ if (!(event->hw.state & PERF_HES_STOPPED)) {
+ sh_pmu->disable(hwc, idx);
+ cpuc->events[idx] = NULL;
+ event->hw.state |= PERF_HES_STOPPED;
+ }
- barrier();
+ if ((flags & PERF_EF_UPDATE) && !(event->hw.state & PERF_HES_UPTODATE)) {
+ sh_perf_event_update(event, &event->hw, idx);
+ event->hw.state |= PERF_HES_UPTODATE;
+ }
+}
- sh_perf_event_update(event, &event->hw, idx);
+static void sh_pmu_start(struct perf_event *event, int flags)
+{
+ struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+ struct hw_perf_event *hwc = &event->hw;
+ int idx = hwc->idx;
- cpuc->events[idx] = NULL;
- clear_bit(idx, cpuc->used_mask);
+ if (WARN_ON_ONCE(idx == -1))
+ return;
+
+ if (flags & PERF_EF_RELOAD)
+ WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
+
+ cpuc->events[idx] = event;
+ event->hw.state = 0;
+ sh_pmu->enable(hwc, idx);
+}
+
+static void sh_pmu_del(struct perf_event *event, int flags)
+{
+ struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+
+ sh_pmu_stop(event, PERF_EF_UPDATE);
+ __clear_bit(event->hw.idx, cpuc->used_mask);
perf_event_update_userpage(event);
}
-static int sh_pmu_enable(struct perf_event *event)
+static int sh_pmu_add(struct perf_event *event, int flags)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
struct hw_perf_event *hwc = &event->hw;
@@ -234,21 +260,20 @@
perf_pmu_disable(event->pmu);
- if (test_and_set_bit(idx, cpuc->used_mask)) {
+ if (__test_and_set_bit(idx, cpuc->used_mask)) {
idx = find_first_zero_bit(cpuc->used_mask, sh_pmu->num_events);
if (idx == sh_pmu->num_events)
goto out;
- set_bit(idx, cpuc->used_mask);
+ __set_bit(idx, cpuc->used_mask);
hwc->idx = idx;
}
sh_pmu->disable(hwc, idx);
- cpuc->events[idx] = event;
- set_bit(idx, cpuc->active_mask);
-
- sh_pmu->enable(hwc, idx);
+ event->hw.state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
+ if (flags & PERF_EF_START)
+ sh_pmu_start(event, PERF_EF_RELOAD);
perf_event_update_userpage(event);
ret = 0;
@@ -285,7 +310,7 @@
return err;
}
-static void sh_pmu_pmu_enable(struct pmu *pmu)
+static void sh_pmu_enable(struct pmu *pmu)
{
if (!sh_pmu_initialized())
return;
@@ -293,7 +318,7 @@
sh_pmu->enable_all();
}
-static void sh_pmu_pmu_disable(struct pmu *pmu)
+static void sh_pmu_disable(struct pmu *pmu)
{
if (!sh_pmu_initialized())
return;
@@ -302,11 +327,13 @@
}
static struct pmu pmu = {
- .pmu_enable = sh_pmu_pmu_enable,
- .pmu_disable = sh_pmu_pmu_disable,
+ .pmu_enable = sh_pmu_enable,
+ .pmu_disable = sh_pmu_disable,
.event_init = sh_pmu_event_init,
- .enable = sh_pmu_enable,
- .disable = sh_pmu_disable,
+ .add = sh_pmu_add,
+ .del = sh_pmu_del,
+ .start = sh_pmu_start,
+ .stop = sh_pmu_stop,
.read = sh_pmu_read,
};
@@ -334,15 +361,15 @@
return NOTIFY_OK;
}
-int __cpuinit register_sh_pmu(struct sh_pmu *pmu)
+int __cpuinit register_sh_pmu(struct sh_pmu *_pmu)
{
if (sh_pmu)
return -EBUSY;
- sh_pmu = pmu;
+ sh_pmu = _pmu;
- pr_info("Performance Events: %s support registered\n", pmu->name);
+ pr_info("Performance Events: %s support registered\n", _pmu->name);
- WARN_ON(pmu->num_events > MAX_HWEVENTS);
+ WARN_ON(_pmu->num_events > MAX_HWEVENTS);
perf_pmu_register(&pmu);
perf_cpu_notifier(sh_pmu_notifier);
diff --git a/arch/sparc/kernel/perf_event.c b/arch/sparc/kernel/perf_event.c
index 37cae67..516be23 100644
--- a/arch/sparc/kernel/perf_event.c
+++ b/arch/sparc/kernel/perf_event.c
@@ -658,13 +658,16 @@
enc = perf_event_get_enc(cpuc->events[i]);
pcr &= ~mask_for_index(idx);
- pcr |= event_encoding(enc, idx);
+ if (hwc->state & PERF_HES_STOPPED)
+ pcr |= nop_for_index(idx);
+ else
+ pcr |= event_encoding(enc, idx);
}
out:
return pcr;
}
-static void sparc_pmu_pmu_enable(struct pmu *pmu)
+static void sparc_pmu_enable(struct pmu *pmu)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
u64 pcr;
@@ -691,7 +694,7 @@
pcr_ops->write(cpuc->pcr);
}
-static void sparc_pmu_pmu_disable(struct pmu *pmu)
+static void sparc_pmu_disable(struct pmu *pmu)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
u64 val;
@@ -710,48 +713,6 @@
pcr_ops->write(cpuc->pcr);
}
-static void sparc_pmu_disable(struct perf_event *event)
-{
- struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
- struct hw_perf_event *hwc = &event->hw;
- unsigned long flags;
- int i;
-
- local_irq_save(flags);
- perf_pmu_disable(event->pmu);
-
- for (i = 0; i < cpuc->n_events; i++) {
- if (event == cpuc->event[i]) {
- int idx = cpuc->current_idx[i];
-
- /* Shift remaining entries down into
- * the existing slot.
- */
- while (++i < cpuc->n_events) {
- cpuc->event[i - 1] = cpuc->event[i];
- cpuc->events[i - 1] = cpuc->events[i];
- cpuc->current_idx[i - 1] =
- cpuc->current_idx[i];
- }
-
- /* Absorb the final count and turn off the
- * event.
- */
- sparc_pmu_disable_event(cpuc, hwc, idx);
- barrier();
- sparc_perf_event_update(event, hwc, idx);
-
- perf_event_update_userpage(event);
-
- cpuc->n_events--;
- break;
- }
- }
-
- perf_pmu_enable(event->pmu);
- local_irq_restore(flags);
-}
-
static int active_event_index(struct cpu_hw_events *cpuc,
struct perf_event *event)
{
@@ -765,6 +726,74 @@
return cpuc->current_idx[i];
}
+static void sparc_pmu_start(struct perf_event *event, int flags)
+{
+ struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+ int idx = active_event_index(cpuc, event);
+
+ if (flags & PERF_EF_RELOAD) {
+ WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
+ sparc_perf_event_set_period(event, &event->hw, idx);
+ }
+
+ event->hw.state = 0;
+
+ sparc_pmu_enable_event(cpuc, &event->hw, idx);
+}
+
+static void sparc_pmu_stop(struct perf_event *event, int flags)
+{
+ struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+ int idx = active_event_index(cpuc, event);
+
+ if (!(event->hw.state & PERF_HES_STOPPED)) {
+ sparc_pmu_disable_event(cpuc, &event->hw, idx);
+ event->hw.state |= PERF_HES_STOPPED;
+ }
+
+ if (!(event->hw.state & PERF_HES_UPTODATE) && (flags & PERF_EF_UPDATE)) {
+ sparc_perf_event_update(event, &event->hw, idx);
+ event->hw.state |= PERF_HES_UPTODATE;
+ }
+}
+
+static void sparc_pmu_del(struct perf_event *event, int _flags)
+{
+ struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+ unsigned long flags;
+ int i;
+
+ local_irq_save(flags);
+ perf_pmu_disable(event->pmu);
+
+ for (i = 0; i < cpuc->n_events; i++) {
+ if (event == cpuc->event[i]) {
+ /* Absorb the final count and turn off the
+ * event.
+ */
+ sparc_pmu_stop(event, PERF_EF_UPDATE);
+
+ /* Shift remaining entries down into
+ * the existing slot.
+ */
+ while (++i < cpuc->n_events) {
+ cpuc->event[i - 1] = cpuc->event[i];
+ cpuc->events[i - 1] = cpuc->events[i];
+ cpuc->current_idx[i - 1] =
+ cpuc->current_idx[i];
+ }
+
+ perf_event_update_userpage(event);
+
+ cpuc->n_events--;
+ break;
+ }
+ }
+
+ perf_pmu_enable(event->pmu);
+ local_irq_restore(flags);
+}
+
static void sparc_pmu_read(struct perf_event *event)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
@@ -774,15 +803,6 @@
sparc_perf_event_update(event, hwc, idx);
}
-static void sparc_pmu_unthrottle(struct perf_event *event)
-{
- struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
- int idx = active_event_index(cpuc, event);
- struct hw_perf_event *hwc = &event->hw;
-
- sparc_pmu_enable_event(cpuc, hwc, idx);
-}
-
static atomic_t active_events = ATOMIC_INIT(0);
static DEFINE_MUTEX(pmc_grab_mutex);
@@ -984,7 +1004,7 @@
return n;
}
-static int sparc_pmu_enable(struct perf_event *event)
+static int sparc_pmu_add(struct perf_event *event, int ef_flags)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
int n0, ret = -EAGAIN;
@@ -1001,6 +1021,10 @@
cpuc->events[n0] = event->hw.event_base;
cpuc->current_idx[n0] = PIC_NO_INDEX;
+ event->hw.state = PERF_HES_UPTODATE;
+ if (!(ef_flags & PERF_EF_START))
+ event->hw.state |= PERF_HES_STOPPED;
+
/*
* If group events scheduling transaction was started,
* skip the schedulability test here, it will be peformed
@@ -1156,13 +1180,14 @@
}
static struct pmu pmu = {
- .pmu_enable = sparc_pmu_pmu_enable,
- .pmu_disable = sparc_pmu_pmu_disable,
+ .pmu_enable = sparc_pmu_enable,
+ .pmu_disable = sparc_pmu_disable,
.event_init = sparc_pmu_event_init,
- .enable = sparc_pmu_enable,
- .disable = sparc_pmu_disable,
+ .add = sparc_pmu_add,
+ .del = sparc_pmu_del,
+ .start = sparc_pmu_start,
+ .stop = sparc_pmu_stop,
.read = sparc_pmu_read,
- .unthrottle = sparc_pmu_unthrottle,
.start_txn = sparc_pmu_start_txn,
.cancel_txn = sparc_pmu_cancel_txn,
.commit_txn = sparc_pmu_commit_txn,
@@ -1243,7 +1268,7 @@
continue;
if (perf_event_overflow(event, 1, &data, regs))
- sparc_pmu_disable_event(cpuc, hwc, idx);
+ sparc_pmu_stop(event, 0);
}
return NOTIFY_STOP;
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 79705ac..dd6fec7 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -583,7 +583,7 @@
}
}
-static void x86_pmu_pmu_disable(struct pmu *pmu)
+static void x86_pmu_disable(struct pmu *pmu)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
@@ -800,10 +800,10 @@
hwc->last_tag == cpuc->tags[i];
}
-static int x86_pmu_start(struct perf_event *event);
-static void x86_pmu_stop(struct perf_event *event);
+static void x86_pmu_start(struct perf_event *event, int flags);
+static void x86_pmu_stop(struct perf_event *event, int flags);
-static void x86_pmu_pmu_enable(struct pmu *pmu)
+static void x86_pmu_enable(struct pmu *pmu)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
struct perf_event *event;
@@ -839,7 +839,14 @@
match_prev_assignment(hwc, cpuc, i))
continue;
- x86_pmu_stop(event);
+ /*
+ * Ensure we don't accidentally enable a stopped
+ * counter simply because we rescheduled.
+ */
+ if (hwc->state & PERF_HES_STOPPED)
+ hwc->state |= PERF_HES_ARCH;
+
+ x86_pmu_stop(event, PERF_EF_UPDATE);
}
for (i = 0; i < cpuc->n_events; i++) {
@@ -851,7 +858,10 @@
else if (i < n_running)
continue;
- x86_pmu_start(event);
+ if (hwc->state & PERF_HES_ARCH)
+ continue;
+
+ x86_pmu_start(event, PERF_EF_RELOAD);
}
cpuc->n_added = 0;
perf_events_lapic_init();
@@ -952,15 +962,12 @@
}
/*
- * activate a single event
+ * Add a single event to the PMU.
*
* The event is added to the group of enabled events
* but only if it can be scehduled with existing events.
- *
- * Called with PMU disabled. If successful and return value 1,
- * then guaranteed to call perf_enable() and hw_perf_enable()
*/
-static int x86_pmu_enable(struct perf_event *event)
+static int x86_pmu_add(struct perf_event *event, int flags)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
struct hw_perf_event *hwc;
@@ -975,10 +982,14 @@
if (ret < 0)
goto out;
+ hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
+ if (!(flags & PERF_EF_START))
+ hwc->state |= PERF_HES_ARCH;
+
/*
* If group events scheduling transaction was started,
* skip the schedulability test here, it will be peformed
- * at commit time(->commit_txn) as a whole
+ * at commit time (->commit_txn) as a whole
*/
if (cpuc->group_flag & PERF_EVENT_TXN)
goto done_collect;
@@ -1003,27 +1014,28 @@
return ret;
}
-static int x86_pmu_start(struct perf_event *event)
+static void x86_pmu_start(struct perf_event *event, int flags)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
int idx = event->hw.idx;
- if (idx == -1)
- return -EAGAIN;
+ if (WARN_ON_ONCE(!(event->hw.state & PERF_HES_STOPPED)))
+ return;
- x86_perf_event_set_period(event);
+ if (WARN_ON_ONCE(idx == -1))
+ return;
+
+ if (flags & PERF_EF_RELOAD) {
+ WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
+ x86_perf_event_set_period(event);
+ }
+
+ event->hw.state = 0;
+
cpuc->events[idx] = event;
__set_bit(idx, cpuc->active_mask);
x86_pmu.enable(event);
perf_event_update_userpage(event);
-
- return 0;
-}
-
-static void x86_pmu_unthrottle(struct perf_event *event)
-{
- int ret = x86_pmu_start(event);
- WARN_ON_ONCE(ret);
}
void perf_event_print_debug(void)
@@ -1080,27 +1092,29 @@
local_irq_restore(flags);
}
-static void x86_pmu_stop(struct perf_event *event)
+static void x86_pmu_stop(struct perf_event *event, int flags)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
struct hw_perf_event *hwc = &event->hw;
- int idx = hwc->idx;
- if (!__test_and_clear_bit(idx, cpuc->active_mask))
- return;
+ if (__test_and_clear_bit(hwc->idx, cpuc->active_mask)) {
+ x86_pmu.disable(event);
+ cpuc->events[hwc->idx] = NULL;
+ WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
+ hwc->state |= PERF_HES_STOPPED;
+ }
- x86_pmu.disable(event);
-
- /*
- * Drain the remaining delta count out of a event
- * that we are disabling:
- */
- x86_perf_event_update(event);
-
- cpuc->events[idx] = NULL;
+ if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
+ /*
+ * Drain the remaining delta count out of a event
+ * that we are disabling:
+ */
+ x86_perf_event_update(event);
+ hwc->state |= PERF_HES_UPTODATE;
+ }
}
-static void x86_pmu_disable(struct perf_event *event)
+static void x86_pmu_del(struct perf_event *event, int flags)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
int i;
@@ -1113,7 +1127,7 @@
if (cpuc->group_flag & PERF_EVENT_TXN)
return;
- x86_pmu_stop(event);
+ x86_pmu_stop(event, PERF_EF_UPDATE);
for (i = 0; i < cpuc->n_events; i++) {
if (event == cpuc->event_list[i]) {
@@ -1165,7 +1179,7 @@
continue;
if (perf_event_overflow(event, 1, &data, regs))
- x86_pmu_stop(event);
+ x86_pmu_stop(event, 0);
}
if (handled)
@@ -1605,15 +1619,17 @@
}
static struct pmu pmu = {
- .pmu_enable = x86_pmu_pmu_enable,
- .pmu_disable = x86_pmu_pmu_disable,
+ .pmu_enable = x86_pmu_enable,
+ .pmu_disable = x86_pmu_disable,
+
.event_init = x86_pmu_event_init,
- .enable = x86_pmu_enable,
- .disable = x86_pmu_disable,
+
+ .add = x86_pmu_add,
+ .del = x86_pmu_del,
.start = x86_pmu_start,
.stop = x86_pmu_stop,
.read = x86_pmu_read,
- .unthrottle = x86_pmu_unthrottle,
+
.start_txn = x86_pmu_start_txn,
.cancel_txn = x86_pmu_cancel_txn,
.commit_txn = x86_pmu_commit_txn,
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index ee05c90..82395f2 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -763,7 +763,7 @@
data.period = event->hw.last_period;
if (perf_event_overflow(event, 1, &data, regs))
- x86_pmu_stop(event);
+ x86_pmu_stop(event, 0);
}
/*
diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index 18018d1..9893a2f 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -491,7 +491,7 @@
regs.flags &= ~PERF_EFLAGS_EXACT;
if (perf_event_overflow(event, 1, &data, ®s))
- x86_pmu_stop(event);
+ x86_pmu_stop(event, 0);
}
static void intel_pmu_drain_pebs_core(struct pt_regs *iregs)