Messages in this thread | | | Date | Thu, 12 Apr 2012 09:16:38 +0200 | From | Juri Lelli <> | Subject | Re: [PATCH 11/16] sched: add latency tracing for -deadline tasks. |
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On 04/11/2012 11:03 PM, Steven Rostedt wrote: > 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 ;-) >
Ouch! Forgot to cut something! :-(
>> + /* >> + * 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;
Yes, way better.
Thanks!
- Juri
>> >> 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) >> > >
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