* [PATCH 1/2] perf, cpu hotplug: Run CPU_STARTING notifiers with irqs disabled
@ 2012-09-13 14:42 Srivatsa S. Bhat
2012-09-13 14:42 ` [PATCH 2/2] perf, cpu hotplug: Use cached value of smp_processor_id() Srivatsa S. Bhat
2012-10-05 10:43 ` [PATCH 1/2] perf, cpu hotplug: Run CPU_STARTING notifiers with irqs disabled Srivatsa S. Bhat
0 siblings, 2 replies; 3+ messages in thread
From: Srivatsa S. Bhat @ 2012-09-13 14:42 UTC (permalink / raw)
To: a.p.zijlstra, acme; +Cc: mingo, paulus, linux-kernel, Srivatsa S. Bhat
The CPU_STARTING notifiers are supposed to be run with irqs disabled. But the
perf_cpu_notifier() macro invokes them without doing that. Fix it.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
---
include/linux/perf_event.h | 3 +++
1 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 7602ccb..cc4574d 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1346,10 +1346,13 @@ static inline void perf_event_task_tick(void) { }
do { \
static struct notifier_block fn##_nb __cpuinitdata = \
{ .notifier_call = fn, .priority = CPU_PRI_PERF }; \
+ unsigned long flags; \
fn(&fn##_nb, (unsigned long)CPU_UP_PREPARE, \
(void *)(unsigned long)smp_processor_id()); \
+ local_irq_save(flags); \
fn(&fn##_nb, (unsigned long)CPU_STARTING, \
(void *)(unsigned long)smp_processor_id()); \
+ local_irq_restore(flags); \
fn(&fn##_nb, (unsigned long)CPU_ONLINE, \
(void *)(unsigned long)smp_processor_id()); \
register_cpu_notifier(&fn##_nb); \
^ permalink raw reply related [flat|nested] 3+ messages in thread* [PATCH 2/2] perf, cpu hotplug: Use cached value of smp_processor_id()
2012-09-13 14:42 [PATCH 1/2] perf, cpu hotplug: Run CPU_STARTING notifiers with irqs disabled Srivatsa S. Bhat
@ 2012-09-13 14:42 ` Srivatsa S. Bhat
2012-10-05 10:43 ` [PATCH 1/2] perf, cpu hotplug: Run CPU_STARTING notifiers with irqs disabled Srivatsa S. Bhat
1 sibling, 0 replies; 3+ messages in thread
From: Srivatsa S. Bhat @ 2012-09-13 14:42 UTC (permalink / raw)
To: a.p.zijlstra, acme; +Cc: mingo, paulus, linux-kernel, Srivatsa S. Bhat
The perf_cpu_notifier() macro invokes smp_processor_id() multiple
times. Optimize it by using a local variable.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
---
include/linux/perf_event.h | 7 ++++---
1 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index cc4574d..5b5b017 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1346,15 +1346,16 @@ static inline void perf_event_task_tick(void) { }
do { \
static struct notifier_block fn##_nb __cpuinitdata = \
{ .notifier_call = fn, .priority = CPU_PRI_PERF }; \
+ unsigned long cpu = smp_processor_id(); \
unsigned long flags; \
fn(&fn##_nb, (unsigned long)CPU_UP_PREPARE, \
- (void *)(unsigned long)smp_processor_id()); \
+ (void *)(unsigned long)cpu); \
local_irq_save(flags); \
fn(&fn##_nb, (unsigned long)CPU_STARTING, \
- (void *)(unsigned long)smp_processor_id()); \
+ (void *)(unsigned long)cpu); \
local_irq_restore(flags); \
fn(&fn##_nb, (unsigned long)CPU_ONLINE, \
- (void *)(unsigned long)smp_processor_id()); \
+ (void *)(unsigned long)cpu); \
register_cpu_notifier(&fn##_nb); \
} while (0)
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH 1/2] perf, cpu hotplug: Run CPU_STARTING notifiers with irqs disabled
2012-09-13 14:42 [PATCH 1/2] perf, cpu hotplug: Run CPU_STARTING notifiers with irqs disabled Srivatsa S. Bhat
2012-09-13 14:42 ` [PATCH 2/2] perf, cpu hotplug: Use cached value of smp_processor_id() Srivatsa S. Bhat
@ 2012-10-05 10:43 ` Srivatsa S. Bhat
1 sibling, 0 replies; 3+ messages in thread
From: Srivatsa S. Bhat @ 2012-10-05 10:43 UTC (permalink / raw)
To: a.p.zijlstra, mingo; +Cc: acme, paulus, linux-kernel
On 09/13/2012 08:12 PM, Srivatsa S. Bhat wrote:
> The CPU_STARTING notifiers are supposed to be run with irqs disabled. But the
> perf_cpu_notifier() macro invokes them without doing that. Fix it.
>
> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
> ---
Any thoughts on this?
Regards,
Srivatsa S. Bhat
>
> include/linux/perf_event.h | 3 +++
> 1 files changed, 3 insertions(+), 0 deletions(-)
>
> diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
> index 7602ccb..cc4574d 100644
> --- a/include/linux/perf_event.h
> +++ b/include/linux/perf_event.h
> @@ -1346,10 +1346,13 @@ static inline void perf_event_task_tick(void) { }
> do { \
> static struct notifier_block fn##_nb __cpuinitdata = \
> { .notifier_call = fn, .priority = CPU_PRI_PERF }; \
> + unsigned long flags; \
> fn(&fn##_nb, (unsigned long)CPU_UP_PREPARE, \
> (void *)(unsigned long)smp_processor_id()); \
> + local_irq_save(flags); \
> fn(&fn##_nb, (unsigned long)CPU_STARTING, \
> (void *)(unsigned long)smp_processor_id()); \
> + local_irq_restore(flags); \
> fn(&fn##_nb, (unsigned long)CPU_ONLINE, \
> (void *)(unsigned long)smp_processor_id()); \
> register_cpu_notifier(&fn##_nb); \
>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2012-10-05 10:44 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2012-09-13 14:42 [PATCH 1/2] perf, cpu hotplug: Run CPU_STARTING notifiers with irqs disabled Srivatsa S. Bhat
2012-09-13 14:42 ` [PATCH 2/2] perf, cpu hotplug: Use cached value of smp_processor_id() Srivatsa S. Bhat
2012-10-05 10:43 ` [PATCH 1/2] perf, cpu hotplug: Run CPU_STARTING notifiers with irqs disabled Srivatsa S. Bhat
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