* [PATCH] sched,trace: Allow tracing the preemption decision on wakeup
@ 2013-03-14 9:48 Peter Zijlstra
2013-03-14 12:00 ` Steven Rostedt
2013-03-18 11:09 ` [tip:sched/core] sched/tracing: " tip-bot for Peter Zijlstra
0 siblings, 2 replies; 4+ messages in thread
From: Peter Zijlstra @ 2013-03-14 9:48 UTC (permalink / raw)
To: mingo, tglx, Steven Rostedt; +Cc: Mike Galbraith, Paul Turner, LKML
Thomas noted that we do the wakeup preemption check after the wakeup
trace point, this means the tracepoint cannot test/report this decision;
which is rather important for latency sensitive workloads. Therefore
move the tracepoint after doing the preemption check.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
kernel/sched/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index b36635e..849deb9 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1288,8 +1288,8 @@ static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags)
static void
ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags)
{
- trace_sched_wakeup(p, true);
check_preempt_curr(rq, p, wake_flags);
+ trace_sched_wakeup(p, true);
p->state = TASK_RUNNING;
#ifdef CONFIG_SMP
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] sched,trace: Allow tracing the preemption decision on wakeup
2013-03-14 9:48 [PATCH] sched,trace: Allow tracing the preemption decision on wakeup Peter Zijlstra
@ 2013-03-14 12:00 ` Steven Rostedt
2013-03-14 15:42 ` Paul Turner
2013-03-18 11:09 ` [tip:sched/core] sched/tracing: " tip-bot for Peter Zijlstra
1 sibling, 1 reply; 4+ messages in thread
From: Steven Rostedt @ 2013-03-14 12:00 UTC (permalink / raw)
To: Peter Zijlstra; +Cc: mingo, tglx, Mike Galbraith, Paul Turner, LKML
On Thu, 2013-03-14 at 10:48 +0100, Peter Zijlstra wrote:
> Thomas noted that we do the wakeup preemption check after the wakeup
> trace point, this means the tracepoint cannot test/report this decision;
> which is rather important for latency sensitive workloads. Therefore
> move the tracepoint after doing the preemption check.
>
> Suggested-by: Thomas Gleixner <tglx@linutronix.de>
> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
> ---
> kernel/sched/core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index b36635e..849deb9 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -1288,8 +1288,8 @@ static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags)
> static void
> ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags)
> {
> - trace_sched_wakeup(p, true);
> check_preempt_curr(rq, p, wake_flags);
> + trace_sched_wakeup(p, true);
>
> p->state = TASK_RUNNING;
> #ifdef CONFIG_SMP
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] sched,trace: Allow tracing the preemption decision on wakeup
2013-03-14 12:00 ` Steven Rostedt
@ 2013-03-14 15:42 ` Paul Turner
0 siblings, 0 replies; 4+ messages in thread
From: Paul Turner @ 2013-03-14 15:42 UTC (permalink / raw)
Cc: Peter Zijlstra, Ingo Molnar, tglx, Mike Galbraith, LKML
Yeah -- this one is a real no brainer to move; looks good :)
On Thu, Mar 14, 2013 at 5:00 AM, Steven Rostedt <rostedt@goodmis.org> wrote:
> On Thu, 2013-03-14 at 10:48 +0100, Peter Zijlstra wrote:
>> Thomas noted that we do the wakeup preemption check after the wakeup
>> trace point, this means the tracepoint cannot test/report this decision;
>> which is rather important for latency sensitive workloads. Therefore
>> move the tracepoint after doing the preemption check.
>>
>> Suggested-by: Thomas Gleixner <tglx@linutronix.de>
>> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
>
> Acked-by: Steven Rostedt <rostedt@goodmis.org>
>
>> ---
>> kernel/sched/core.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
>> index b36635e..849deb9 100644
>> --- a/kernel/sched/core.c
>> +++ b/kernel/sched/core.c
>> @@ -1288,8 +1288,8 @@ static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags)
>> static void
>> ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags)
>> {
>> - trace_sched_wakeup(p, true);
>> check_preempt_curr(rq, p, wake_flags);
>> + trace_sched_wakeup(p, true);
>>
>> p->state = TASK_RUNNING;
>> #ifdef CONFIG_SMP
>>
>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* [tip:sched/core] sched/tracing: Allow tracing the preemption decision on wakeup
2013-03-14 9:48 [PATCH] sched,trace: Allow tracing the preemption decision on wakeup Peter Zijlstra
2013-03-14 12:00 ` Steven Rostedt
@ 2013-03-18 11:09 ` tip-bot for Peter Zijlstra
1 sibling, 0 replies; 4+ messages in thread
From: tip-bot for Peter Zijlstra @ 2013-03-18 11:09 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, hpa, mingo, a.p.zijlstra, efault, pjt, peterz,
rostedt, tglx
Commit-ID: a8d7ad52a7befbde896276d05c75c90fed48b5bf
Gitweb: http://git.kernel.org/tip/a8d7ad52a7befbde896276d05c75c90fed48b5bf
Author: Peter Zijlstra <peterz@infradead.org>
AuthorDate: Thu, 14 Mar 2013 10:48:39 +0100
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Mon, 18 Mar 2013 10:18:08 +0100
sched/tracing: Allow tracing the preemption decision on wakeup
Thomas noted that we do the wakeup preemption check after the
wakeup trace point, this means the tracepoint cannot test/report
this decision; which is rather important for latency sensitive
workloads. Therefore move the tracepoint after doing the
preemption check.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Paul Turner <pjt@google.com>
Cc: Mike Galbraith <efault@gmx.de>
Link: http://lkml.kernel.org/r/1363254519.26965.9.camel@laptop
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
kernel/sched/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index b36635e..849deb9 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1288,8 +1288,8 @@ static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags)
static void
ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags)
{
- trace_sched_wakeup(p, true);
check_preempt_curr(rq, p, wake_flags);
+ trace_sched_wakeup(p, true);
p->state = TASK_RUNNING;
#ifdef CONFIG_SMP
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2013-03-18 11:10 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2013-03-14 9:48 [PATCH] sched,trace: Allow tracing the preemption decision on wakeup Peter Zijlstra
2013-03-14 12:00 ` Steven Rostedt
2013-03-14 15:42 ` Paul Turner
2013-03-18 11:09 ` [tip:sched/core] sched/tracing: " tip-bot for Peter Zijlstra
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