Commit e221d028 authored by Mike Galbraith's avatar Mike Galbraith Committed by Thomas Gleixner
Browse files

sched,rt: fix isolated CPUs leaving root_task_group indefinitely throttled

Root task group bandwidth replenishment must service all CPUs, regardless of
where the timer was last started, and regardless of the isolation mechanism,
lest 'Quoth the Raven, "Nevermore"' become rt scheduling policy.
Signed-off-by: default avatarMike Galbraith <>
Signed-off-by: default avatarPeter Zijlstra <>

Signed-off-by: default avatarThomas Gleixner <>
parent 35cf4e50
......@@ -788,6 +788,19 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
const struct cpumask *span;
span = sched_rt_period_mask();
* 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;
for_each_cpu(i, span) {
int enqueue = 0;
struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i);
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment