[tip:perf/core] perf: Per PMU disable

tip-bot for Peter Zijlstra
2010-09-09T19:49:53Z

Commit-ID: 33696fc0d141bbbcb12f75b69608ea83282e3117
Gitweb: http://git.kernel.org/tip/33696fc0d141bbbcb12f75b69608ea83282e3117
Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Mon, 14 Jun 2010 08:49:00 +0200
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Thu, 9 Sep 2010 20:46:29 +0200

perf: Per PMU disable

Changes perf_disable() into perf_pmu_disable().

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>
---
arch/alpha/kernel/perf_event.c | 30 ++++++++++++-----------
arch/arm/kernel/perf_event.c | 28 +++++++++++-----------
arch/powerpc/kernel/perf_event.c | 24 ++++++++++--------
arch/powerpc/kernel/perf_event_fsl_emb.c | 18 ++++++++------
arch/sh/kernel/perf_event.c | 38 +++++++++++++++--------------
arch/sparc/kernel/perf_event.c | 20 ++++++++-------
arch/x86/kernel/cpu/perf_event.c | 16 +++++++-----
include/linux/perf_event.h | 13 +++++----
kernel/perf_event.c | 31 +++++++++++++++---------
9 files changed, 119 insertions(+), 99 deletions(-)

diff --git a/arch/alpha/kernel/perf_event.c b/arch/alpha/kernel/perf_event.c
index 19660b5..3e26073 100644
--- a/arch/alpha/kernel/perf_event.c
+++ b/arch/alpha/kernel/perf_event.c
@@ -435,7 +435,7 @@ static int alpha_pmu_enable(struct perf_event *event)
* nevertheless we disable the PMCs first to enable a potential
* final PMI to occur before we disable interrupts.
*/
- perf_disable();
+ perf_pmu_disable(event->pmu);
local_irq_save(flags);

/* Default to error to be returned */
@@ -456,7 +456,7 @@ static int alpha_pmu_enable(struct perf_event *event)
}

local_irq_restore(flags);
- perf_enable();
+ perf_pmu_enable(event->pmu);

return ret;
}
@@ -474,7 +474,7 @@ static void alpha_pmu_disable(struct perf_event *event)
unsigned long flags;
int j;

- perf_disable();
+ perf_pmu_disable(event->pmu);
local_irq_save(flags);

for (j = 0; j < cpuc->n_events; j++) {
@@ -502,7 +502,7 @@ static void alpha_pmu_disable(struct perf_event *event)
}

local_irq_restore(flags);
- perf_enable();
+ perf_pmu_enable(event->pmu);
}

@@ -668,18 +668,10 @@ static int alpha_pmu_event_init(struct perf_event *event)
return err;
}

-static struct pmu pmu = {
- .event_init = alpha_pmu_event_init,
- .enable = alpha_pmu_enable,
- .disable = alpha_pmu_disable,
- .read = alpha_pmu_read,
- .unthrottle = alpha_pmu_unthrottle,
-};
-
/*
* Main entry point - enable HW performance counters.
*/
-void hw_perf_enable(void)
+static void alpha_pmu_pmu_enable(struct pmu *pmu)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);

@@ -705,7 +697,7 @@ void hw_perf_enable(void)
* Main entry point - disable HW performance counters.
*/

-void hw_perf_disable(void)
+static void alpha_pmu_pmu_disable(struct pmu *pmu)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);

@@ -718,6 +710,16 @@ void hw_perf_disable(void)
wrperfmon(PERFMON_CMD_DISABLE, cpuc->idx_mask);
}

+static struct pmu pmu = {
+ .pmu_enable = alpha_pmu_pmu_enable,
+ .pmu_disable = alpha_pmu_pmu_disable,
+ .event_init = alpha_pmu_event_init,
+ .enable = alpha_pmu_enable,
+ .disable = alpha_pmu_disable,
+ .read = alpha_pmu_read,
+ .unthrottle = alpha_pmu_unthrottle,
+};
+

/*
* Main entry point - don't know when this is called but it
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index afc92c5..3343f3f 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -277,7 +277,7 @@ armpmu_enable(struct perf_event *event)
int idx;
int err = 0;

- perf_disable();
+ perf_pmu_disable(event->pmu);

/* If we don't have a space for the counter then finish early. */
idx = armpmu->get_event_idx(cpuc, hwc);
@@ -305,7 +305,7 @@ armpmu_enable(struct perf_event *event)
perf_event_update_userpage(event);

out:
- perf_enable();
+ perf_pmu_enable(event->pmu);
return err;
}

@@ -534,16 +534,7 @@ static int armpmu_event_init(struct perf_event *event)
return err;
}

-static struct pmu pmu = {
- .event_init = armpmu_event_init,
- .enable = armpmu_enable,
- .disable = armpmu_disable,
- .unthrottle = armpmu_unthrottle,
- .read = armpmu_read,
-};
-
-void
-hw_perf_enable(void)
+static void armpmu_pmu_enable(struct pmu *pmu)
{
/* Enable all of the perf events on hardware. */
int idx;
@@ -564,13 +555,22 @@ hw_perf_enable(void)
armpmu->start();
}

-void
-hw_perf_disable(void)
+static void armpmu_pmu_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,
+};
+
/*
* ARMv6 Performance counter handling code.
*
diff --git a/arch/powerpc/kernel/perf_event.c b/arch/powerpc/kernel/perf_event.c
index c140882..deb84bb 100644
--- a/arch/powerpc/kernel/perf_event.c
+++ b/arch/powerpc/kernel/perf_event.c
@@ -517,7 +517,7 @@ static void write_mmcr0(struct cpu_hw_events *cpuhw, unsigned long mmcr0)
* Disable all events to prevent PMU interrupts and to allow
* events to be added or removed.
*/
-void hw_perf_disable(void)
+static void power_pmu_pmu_disable(struct pmu *pmu)
{
struct cpu_hw_events *cpuhw;
unsigned long flags;
@@ -565,7 +565,7 @@ void hw_perf_disable(void)
* If we were previously disabled and events were added, then
* put the new config on the PMU.
*/
-void hw_perf_enable(void)
+static void power_pmu_pmu_enable(struct pmu *pmu)
{
struct perf_event *event;
struct cpu_hw_events *cpuhw;
@@ -735,7 +735,7 @@ static int power_pmu_enable(struct perf_event *event)
int ret = -EAGAIN;

local_irq_save(flags);
- perf_disable();
+ perf_pmu_disable(event->pmu);

/*
* Add the event to the list (if there is room)
@@ -769,7 +769,7 @@ nocheck:

ret = 0;
out:
- perf_enable();
+ perf_pmu_enable(event->pmu);
local_irq_restore(flags);
return ret;
}
@@ -784,7 +784,7 @@ static void power_pmu_disable(struct perf_event *event)
unsigned long flags;

local_irq_save(flags);
- perf_disable();
+ perf_pmu_disable(event->pmu);

power_pmu_read(event);

@@ -821,7 +821,7 @@ static void power_pmu_disable(struct perf_event *event)
cpuhw->mmcr[0] &= ~(MMCR0_PMXE | MMCR0_FCECE);
}

- perf_enable();
+ perf_pmu_enable(event->pmu);
local_irq_restore(flags);
}

@@ -837,7 +837,7 @@ static void power_pmu_unthrottle(struct perf_event *event)
if (!event->hw.idx || !event->hw.sample_period)
return;
local_irq_save(flags);
- perf_disable();
+ perf_pmu_disable(event->pmu);
power_pmu_read(event);
left = event->hw.sample_period;
event->hw.last_period = left;
@@ -848,7 +848,7 @@ static void power_pmu_unthrottle(struct perf_event *event)
local64_set(&event->hw.prev_count, val);
local64_set(&event->hw.period_left, left);
perf_event_update_userpage(event);
- perf_enable();
+ perf_pmu_enable(event->pmu);
local_irq_restore(flags);
}

@@ -861,7 +861,7 @@ void power_pmu_start_txn(struct pmu *pmu)
{
struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);

- perf_disable();
+ perf_pmu_disable(pmu);
cpuhw->group_flag |= PERF_EVENT_TXN;
cpuhw->n_txn_start = cpuhw->n_events;
}
@@ -876,7 +876,7 @@ void power_pmu_cancel_txn(struct pmu *pmu)
struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);

cpuhw->group_flag &= ~PERF_EVENT_TXN;
- perf_enable();
+ perf_pmu_enable(pmu);
}

/*
@@ -903,7 +903,7 @@ int power_pmu_commit_txn(struct pmu *pmu)
cpuhw->event[i]->hw.config = cpuhw->events[i];

cpuhw->group_flag &= ~PERF_EVENT_TXN;
- perf_enable();
+ perf_pmu_enable(pmu);
return 0;
}

@@ -1131,6 +1131,8 @@ static int power_pmu_event_init(struct perf_event *event)
}

struct pmu power_pmu = {
+ .pmu_enable = power_pmu_pmu_enable,
+ .pmu_disable = power_pmu_pmu_disable,
.event_init = power_pmu_event_init,
.enable = power_pmu_enable,
.disable = power_pmu_disable,
diff --git a/arch/powerpc/kernel/perf_event_fsl_emb.c b/arch/powerpc/kernel/perf_event_fsl_emb.c
index 9bc84a7..84b1974 100644
--- a/arch/powerpc/kernel/perf_event_fsl_emb.c
+++ b/arch/powerpc/kernel/perf_event_fsl_emb.c
@@ -177,7 +177,7 @@ static void fsl_emb_pmu_read(struct perf_event *event)
* Disable all events to prevent PMU interrupts and to allow
* events to be added or removed.
*/
-void hw_perf_disable(void)
+static void fsl_emb_pmu_pmu_disable(struct pmu *pmu)
{
struct cpu_hw_events *cpuhw;
unsigned long flags;
@@ -216,7 +216,7 @@ void hw_perf_disable(void)
* If we were previously disabled and events were added, then
* put the new config on the PMU.
*/
-void hw_perf_enable(void)
+static void fsl_emb_pmu_pmu_enable(struct pmu *pmu)
{
struct cpu_hw_events *cpuhw;
unsigned long flags;
@@ -271,7 +271,7 @@ static int fsl_emb_pmu_enable(struct perf_event *event)
u64 val;
int i;

- perf_disable();
+ perf_pmu_disable(event->pmu);
cpuhw = &get_cpu_var(cpu_hw_events);

if (event->hw.config & FSL_EMB_EVENT_RESTRICTED)
@@ -311,7 +311,7 @@ static int fsl_emb_pmu_enable(struct perf_event *event)
ret = 0;
out:
put_cpu_var(cpu_hw_events);
- perf_enable();
+ perf_pmu_enable(event->pmu);
return ret;
}

@@ -321,7 +321,7 @@ static void fsl_emb_pmu_disable(struct perf_event *event)
struct cpu_hw_events *cpuhw;
int i = event->hw.idx;

- perf_disable();
+ perf_pmu_disable(event->pmu);
if (i < 0)
goto out;

@@ -349,7 +349,7 @@ static void fsl_emb_pmu_disable(struct perf_event *event)
cpuhw->n_events--;

out:
- perf_enable();
+ perf_pmu_enable(event->pmu);
put_cpu_var(cpu_hw_events);
}

@@ -367,7 +367,7 @@ static void fsl_emb_pmu_unthrottle(struct perf_event *event)
if (event->hw.idx < 0 || !event->hw.sample_period)
return;
local_irq_save(flags);
- perf_disable();
+ perf_pmu_disable(event->pmu);
fsl_emb_pmu_read(event);
left = event->hw.sample_period;
event->hw.last_period = left;
@@ -378,7 +378,7 @@ static void fsl_emb_pmu_unthrottle(struct perf_event *event)
local64_set(&event->hw.prev_count, val);
local64_set(&event->hw.period_left, left);
perf_event_update_userpage(event);
- perf_enable();
+ perf_pmu_enable(event->pmu);
local_irq_restore(flags);
}

@@ -524,6 +524,8 @@ static int fsl_emb_pmu_event_init(struct perf_event *event)
}

static struct pmu fsl_emb_pmu = {
+ .pmu_enable = fsl_emb_pmu_pmu_enable,
+ .pmu_disable = fsl_emb_pmu_pmu_disable,
.event_init = fsl_emb_pmu_event_init,
.enable = fsl_emb_pmu_enable,
.disable = fsl_emb_pmu_disable,
diff --git a/arch/sh/kernel/perf_event.c b/arch/sh/kernel/perf_event.c
index d042989..4bbe190 100644
--- a/arch/sh/kernel/perf_event.c
+++ b/arch/sh/kernel/perf_event.c
@@ -232,7 +232,7 @@ static int sh_pmu_enable(struct perf_event *event)
int idx = hwc->idx;
int ret = -EAGAIN;

- perf_disable();
+ perf_pmu_disable(event->pmu);

if (test_and_set_bit(idx, cpuc->used_mask)) {
idx = find_first_zero_bit(cpuc->used_mask, sh_pmu->num_events);
@@ -253,7 +253,7 @@ static int sh_pmu_enable(struct perf_event *event)
perf_event_update_userpage(event);
ret = 0;
out:
- perf_enable();
+ perf_pmu_enable(event->pmu);
return ret;
}

@@ -285,7 +285,25 @@ static int sh_pmu_event_init(struct perf_event *event)
return err;
}

+static void sh_pmu_pmu_enable(struct pmu *pmu)
+{
+ if (!sh_pmu_initialized())
+ return;
+
+ sh_pmu->enable_all();
+}
+
+static void sh_pmu_pmu_disable(struct pmu *pmu)
+{
+ if (!sh_pmu_initialized())
+ return;
+
+ sh_pmu->disable_all();
+}
+
static struct pmu pmu = {
+ .pmu_enable = sh_pmu_pmu_enable,
+ .pmu_disable = sh_pmu_pmu_disable,
.event_init = sh_pmu_event_init,
.enable = sh_pmu_enable,
.disable = sh_pmu_disable,
@@ -316,22 +334,6 @@ sh_pmu_notifier(struct notifier_block *self, unsigned long action, void *hcpu)
return NOTIFY_OK;
}

-void hw_perf_enable(void)
-{
- if (!sh_pmu_initialized())
- return;
-
- sh_pmu->enable_all();
-}
-
-void hw_perf_disable(void)
-{
- if (!sh_pmu_initialized())
- return;
-
- sh_pmu->disable_all();
-}
-
int __cpuinit register_sh_pmu(struct sh_pmu *pmu)
{
if (sh_pmu)
diff --git a/arch/sparc/kernel/perf_event.c b/arch/sparc/kernel/perf_event.c
index d0131de..37cae67 100644
--- a/arch/sparc/kernel/perf_event.c
+++ b/arch/sparc/kernel/perf_event.c
@@ -664,7 +664,7 @@ out:
return pcr;
}

-void hw_perf_enable(void)
+static void sparc_pmu_pmu_enable(struct pmu *pmu)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
u64 pcr;
@@ -691,7 +691,7 @@ void hw_perf_enable(void)
pcr_ops->write(cpuc->pcr);
}

-void hw_perf_disable(void)
+static void sparc_pmu_pmu_disable(struct pmu *pmu)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
u64 val;
@@ -718,7 +718,7 @@ static void sparc_pmu_disable(struct perf_event *event)
int i;

local_irq_save(flags);
- perf_disable();
+ perf_pmu_disable(event->pmu);

for (i = 0; i < cpuc->n_events; i++) {
if (event == cpuc->event[i]) {
@@ -748,7 +748,7 @@ static void sparc_pmu_disable(struct perf_event *event)
}
}

- perf_enable();
+ perf_pmu_enable(event->pmu);
local_irq_restore(flags);
}

@@ -991,7 +991,7 @@ static int sparc_pmu_enable(struct perf_event *event)
unsigned long flags;

local_irq_save(flags);
- perf_disable();
+ perf_pmu_disable(event->pmu);

n0 = cpuc->n_events;
if (n0 >= perf_max_events)
@@ -1020,7 +1020,7 @@ nocheck:

ret = 0;
out:
- perf_enable();
+ perf_pmu_enable(event->pmu);
local_irq_restore(flags);
return ret;
}
@@ -1113,7 +1113,7 @@ static void sparc_pmu_start_txn(struct pmu *pmu)
{
struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);

- perf_disable();
+ perf_pmu_disable(pmu);
cpuhw->group_flag |= PERF_EVENT_TXN;
}

@@ -1127,7 +1127,7 @@ static void sparc_pmu_cancel_txn(struct pmu *pmu)
struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);

cpuhw->group_flag &= ~PERF_EVENT_TXN;
- perf_enable();
+ perf_pmu_enable(pmu);
}

/*
@@ -1151,11 +1151,13 @@ static int sparc_pmu_commit_txn(struct pmu *pmu)
return -EAGAIN;

cpuc->group_flag &= ~PERF_EVENT_TXN;
- perf_enable();
+ perf_pmu_enable(pmu);
return 0;
}

static struct pmu pmu = {
+ .pmu_enable = sparc_pmu_pmu_enable,
+ .pmu_disable = sparc_pmu_pmu_disable,
.event_init = sparc_pmu_event_init,
.enable = sparc_pmu_enable,
.disable = sparc_pmu_disable,
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 846070c..79705ac 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_disable_all(void)
}
}

-void hw_perf_disable(void)
+static void x86_pmu_pmu_disable(struct pmu *pmu)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);

@@ -803,7 +803,7 @@ static inline int match_prev_assignment(struct hw_perf_event *hwc,
static int x86_pmu_start(struct perf_event *event);
static void x86_pmu_stop(struct perf_event *event);

-void hw_perf_enable(void)
+static void x86_pmu_pmu_enable(struct pmu *pmu)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
struct perf_event *event;
@@ -969,7 +969,7 @@ static int x86_pmu_enable(struct perf_event *event)

hwc = &event->hw;

- perf_disable();
+ perf_pmu_disable(event->pmu);
n0 = cpuc->n_events;
ret = n = collect_events(cpuc, event, false);
if (ret < 0)
@@ -999,7 +999,7 @@ done_collect:

ret = 0;
out:
- perf_enable();
+ perf_pmu_enable(event->pmu);
return ret;
}

@@ -1436,7 +1436,7 @@ static void x86_pmu_start_txn(struct pmu *pmu)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);

- perf_disable();
+ perf_pmu_disable(pmu);
cpuc->group_flag |= PERF_EVENT_TXN;
cpuc->n_txn = 0;
}
@@ -1456,7 +1456,7 @@ static void x86_pmu_cancel_txn(struct pmu *pmu)
*/
cpuc->n_added -= cpuc->n_txn;
cpuc->n_events -= cpuc->n_txn;
- perf_enable();
+ perf_pmu_enable(pmu);
}

/*
@@ -1486,7 +1486,7 @@ static int x86_pmu_commit_txn(struct pmu *pmu)
memcpy(cpuc->assign, assign, n*sizeof(int));

cpuc->group_flag &= ~PERF_EVENT_TXN;
- perf_enable();
+ perf_pmu_enable(pmu);
return 0;
}

@@ -1605,6 +1605,8 @@ int x86_pmu_event_init(struct perf_event *event)
}

static struct pmu pmu = {
+ .pmu_enable = x86_pmu_pmu_enable,
+ .pmu_disable = x86_pmu_pmu_disable,
.event_init = x86_pmu_event_init,
.enable = x86_pmu_enable,
.disable = x86_pmu_disable,
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 243286a..6abf103 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -563,6 +563,11 @@ struct perf_event;
struct pmu {
struct list_head entry;

+ int *pmu_disable_count;
+
+ void (*pmu_enable) (struct pmu *pmu);
+ void (*pmu_disable) (struct pmu *pmu);
+
/*
* Should return -ENOENT when the @event doesn't match this PMU.
*/
@@ -868,10 +873,8 @@ extern void perf_event_free_task(struct task_struct *task);
extern void set_perf_event_pending(void);
extern void perf_event_do_pending(void);
extern void perf_event_print_debug(void);
-extern void __perf_disable(void);
-extern bool __perf_enable(void);
-extern void perf_disable(void);
-extern void perf_enable(void);
+extern void perf_pmu_disable(struct pmu *pmu);
+extern void perf_pmu_enable(struct pmu *pmu);
extern int perf_event_task_disable(void);
extern int perf_event_task_enable(void);
extern void perf_event_update_userpage(struct perf_event *event);
@@ -1056,8 +1059,6 @@ static inline void perf_event_exit_task(struct task_struct *child) { }
static inline void perf_event_free_task(struct task_struct *task) { }
static inline void perf_event_do_pending(void) { }
static inline void perf_event_print_debug(void) { }
-static inline void perf_disable(void) { }
-static inline void perf_enable(void) { }
static inline int perf_event_task_disable(void) { return -EINVAL; }
static inline int perf_event_task_enable(void) { return -EINVAL; }

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 9a98ce9..5ed0c06 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -71,23 +71,20 @@ static atomic64_t perf_event_id;
*/
static DEFINE_SPINLOCK(perf_resource_lock);

-void __weak hw_perf_disable(void) { barrier(); }
-void __weak hw_perf_enable(void) { barrier(); }
-
void __weak perf_event_print_debug(void) { }

-static DEFINE_PER_CPU(int, perf_disable_count);
-
-void perf_disable(void)
+void perf_pmu_disable(struct pmu *pmu)
{
- if (!__get_cpu_var(perf_disable_count)++)
- hw_perf_disable();
+ int *count = this_cpu_ptr(pmu->pmu_disable_count);
+ if (!(*count)++)
+ pmu->pmu_disable(pmu);
}

-void perf_enable(void)
+void perf_pmu_enable(struct pmu *pmu)
{
- if (!--__get_cpu_var(perf_disable_count))
- hw_perf_enable();
+ int *count = this_cpu_ptr(pmu->pmu_disable_count);
+ if (!--(*count))
+ pmu->pmu_enable(pmu);
}

static void get_ctx(struct perf_event_context *ctx)
@@ -4970,11 +4967,19 @@ static struct srcu_struct pmus_srcu;

int perf_pmu_register(struct pmu *pmu)
{
+ int ret;
+
mutex_lock(&pmus_lock);
+ ret = -ENOMEM;
+ pmu->pmu_disable_count = alloc_percpu(int);
+ if (!pmu->pmu_disable_count)
+ goto unlock;
list_add_rcu(&pmu->entry, &pmus);
+ ret = 0;
+unlock:
mutex_unlock(&pmus_lock);

- return 0;
+ return ret;
}

void perf_pmu_unregister(struct pmu *pmu)
@@ -4984,6 +4989,8 @@ void perf_pmu_unregister(struct pmu *pmu)
mutex_unlock(&pmus_lock);

synchronize_srcu(&pmus_srcu);
+
+ free_percpu(pmu->pmu_disable_count);
}

struct pmu *perf_init_event(struct perf_event *event)