Messages in this thread Patch in this message | | | Subject | Re: [PATCH 11/16] sched: add latency tracing for -deadline tasks. | From | Steven Rostedt <> | Date | Wed, 11 Apr 2012 17:03:42 -0400 |
| |
On Fri, 2012-04-06 at 09:14 +0200, Juri Lelli wrote: > From: Dario Faggioli <raistlin@linux.it> > > It is very likely that systems that wants/needs to use the new > SCHED_DEADLINE policy also want to have the scheduling latency of > the -deadline tasks under control. > > For this reason a new version of the scheduling wakeup latency, > called "wakeup_dl", is introduced. > > As a consequence of applying this patch there will be three wakeup > latency tracer: > * "wakeup", that deals with all tasks in the system; > * "wakeup_rt", that deals with -rt and -deadline tasks only; > * "wakeup_dl", that deals with -deadline tasks only. > > Signed-off-by: Dario Faggioli <raistlin@linux.it> > Signed-off-by: Juri Lelli <juri.lelli@gmail.com> > --- > kernel/trace/trace_sched_wakeup.c | 41 ++++++++++++++++++++++++++++++++++++- > kernel/trace/trace_selftest.c | 30 ++++++++++++++++---------- > 2 files changed, 58 insertions(+), 13 deletions(-) > > diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c > index e4a70c0..9c9b1be 100644 > --- a/kernel/trace/trace_sched_wakeup.c > +++ b/kernel/trace/trace_sched_wakeup.c > @@ -27,6 +27,7 @@ static int wakeup_cpu; > static int wakeup_current_cpu; > static unsigned wakeup_prio = -1; > static int wakeup_rt; > +static int wakeup_dl; > > static arch_spinlock_t wakeup_lock = > (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; > @@ -420,6 +421,17 @@ probe_wakeup(void *ignore, struct task_struct *p, int success) > if ((wakeup_rt && !rt_task(p)) || > p->prio >= wakeup_prio || > p->prio >= current->prio)
I don't think you meant to keep both if statements. Look above and below ;-)
> + /* > + * Semantic is like this: > + * - wakeup tracer handles all tasks in the system, independently > + * from their scheduling class; > + * - wakeup_rt tracer handles tasks belonging to sched_dl and > + * sched_rt class; > + * - wakeup_dl handles tasks belonging to sched_dl class only. > + */ > + if ((wakeup_dl && !dl_task(p)) || > + (wakeup_rt && !dl_task(p) && !rt_task(p)) || > + (p->prio >= wakeup_prio || p->prio >= current->prio)) > return;
Anyway, perhaps this should be broken up, as we don't want the double test, that is, wakeup_rt and wakeup_dl are both checked. Perhaps do:
if (wakeup_dl && !dl_task(p)) return; else if (wakeup_rt && !dl_task(p) && !rt_task(p)) return;
if (p->prio >= wakeup_prio || p->prio >= current->prio) return;
-- Steve
> > pc = preempt_count(); > @@ -431,7 +443,7 @@ probe_wakeup(void *ignore, struct task_struct *p, int success) > arch_spin_lock(&wakeup_lock); > > /* check for races. */ > - if (!tracer_enabled || p->prio >= wakeup_prio) > + if (!tracer_enabled || (!dl_task(p) && p->prio >= wakeup_prio)) > goto out_locked; > > /* reset the trace */ > @@ -539,16 +551,25 @@ static int __wakeup_tracer_init(struct trace_array *tr) >
| |