Messages in this thread Patch in this message | | | Subject | Re: RFC [patch] sched,cgroup_sched: convince RT_GROUP_SCHED throttle to work | From | Mike Galbraith <> | Date | Tue, 10 Apr 2012 11:08:45 +0200 |
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On Sat, 2012-04-07 at 11:54 +0200, Mike Galbraith wrote:
> With this patch, the thing appears to work perfectly, but it doesn't > look correct, since I'm futzing with ->rt_time where I should not.
s/doesn't look/definitely isn't. This failed the "definitely works so may live on despite horrific appearance" test anyway, so how about just stop pretending root isn't global instead?
sched,rt: fix isolated CPUs leaving root_task_group indefinitely throttled
Root task group bandwidth replenishment must service all CPUs regardless of where it was last started.
Signed-off-by: Mike Galbraith <efault@gmx.de> --- kernel/sched/rt.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
--- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -782,6 +782,19 @@ static int do_sched_rt_period_timer(stru const struct cpumask *span; span = sched_rt_period_mask(); +#ifdef CONFIG_RT_GROUP_SCHED + /* + * FIXME: isolated CPUs should really leave the root task group, + * whether they are isolcpus or were isolated via cpusets, lest + * the timer run on a CPU which does not service all runqueues, + * potentially leaving other CPUs indefinitely throttled. If + * isolation is really required, the user will turn the throttle + * off to kill the perturbations it causes anyway. Meanwhile, + * this maintains functionality for boot and/or troubleshooting. + */ + if (rt_b == &root_task_group.rt_bandwidth) + span = cpu_online_mask; +#endif for_each_cpu(i, span) { int enqueue = 0; struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i);
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