Messages in this thread | | | Date | Thu, 19 Apr 2012 15:44:16 +0200 | From | Juri Lelli <> | Subject | Re: [PATCH 06/16] sched: SCHED_DEADLINE push and pull logic |
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On 04/11/2012 06:14 PM, Steven Rostedt wrote: > On Fri, 2012-04-06 at 09:14 +0200, Juri Lelli wrote: > >> +static int latest_cpu_find(struct cpumask *span, >> + struct task_struct *task, >> + struct cpumask *later_mask) >> { >> + const struct sched_dl_entity *dl_se =&task->dl; >> + int cpu, found = -1, best = 0; >> + u64 max_dl = 0; >> + >> + for_each_cpu(cpu, span) { >> + struct rq *rq = cpu_rq(cpu); >> + struct dl_rq *dl_rq =&rq->dl; >> + >> + if (cpumask_test_cpu(cpu,&task->cpus_allowed)&& >> + (!dl_rq->dl_nr_running || dl_time_before(dl_se->deadline, >> + dl_rq->earliest_dl.curr))) { >> + if (later_mask) >> + cpumask_set_cpu(cpu, later_mask); >> + if (!best&& !dl_rq->dl_nr_running) { > > I hate to say this (and I also have yet to look at the patches after > this) but we should really take into account the RT tasks. It would suck > to preempt a normal RT task when a non RT task is running on another > CPU.
Well, this changes in 15/16, but your point remains, and I see it :-). We are currently reworking the push/pull mechanism (15/16 will most probably change as well) to speed it up. I agree that it would be nice to take into accont RT tasks as well, so we'll surely think about it.
>> + best = 1; >> + found = cpu; >> + } else if (!best&& >> + dl_time_before(max_dl, >> + dl_rq->earliest_dl.curr)) { >> + max_dl = dl_rq->earliest_dl.curr; >> + found = cpu; >> + } >> + } else if (later_mask) >> + cpumask_clear_cpu(cpu, later_mask); >> + } >> + >> + return found; >> +} > >
Thanks,
- Juri
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