Messages in this thread | | | Date | Tue, 6 May 2014 10:29:56 +0900 | From | Dongsheng Yang <> | Subject | Re: [PATCH] sched: Move the wakeup tracepoint from ttwu_do_wakeup() to ttwu_activate(). |
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On 05/06/2014 11:06 AM, Steven Rostedt wrote: > On Tue, 6 May 2014 09:19:51 +0900 > Dongsheng Yang <yangds.fnst@cn.fujitsu.com> wrote: > > I wonder if we should have the event, or way to distinguish the > difference. Hmm, there's that "success" parameter in the tracepoint. > Could we possible be able to trace events where the success is true > only if it was actually waking the event, and false otherwise? > > Having the sched_wakeup trace event show you when something woke the > task up may still be useful information. For example, you add yourself > to a wait queue and want to see the "wakeup". If we only show it for > tasks that really woke up then we wont see it for those that added > itself to a waitqueue but was "woken" before it could schedule out. > > The original sched_wakeup did this, but with the ttwu rewrite, it was > lost.
Ha, got what you mean. Yes, we can take the use of success in sched_wakeup event. > > Something like below? > > -- Steve > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index 268a45e..e583989 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -1404,6 +1404,7 @@ static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags) > { > activate_task(rq, p, en_flags); > p->on_rq = 1; > + trace_sched_wakeup(p, true); > > /* if a worker is waking up, notify workqueue */ > if (p->flags & PF_WQ_WORKER) > @@ -1417,7 +1418,6 @@ static void > ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) > { > check_preempt_curr(rq, p, wake_flags); > - trace_sched_wakeup(p, true); > > p->state = TASK_RUNNING; > #ifdef CONFIG_SMP > @@ -1662,6 +1662,8 @@ static void try_to_wake_up_local(struct task_struct *p) > > if (!p->on_rq) > ttwu_activate(rq, p, ENQUEUE_WAKEUP); > + else > + trace_sched_wakeup(p, false);
Also we should add a false trace point in ttwu_remote(). > > ttwu_do_wakeup(rq, p, 0); > ttwu_stat(p, smp_processor_id(), 0);
Thanx steven, I will send a new patch as you suggested here. > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > . >
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