sched: fix 2.6.27-rc5 couldn't boot on tulsa machine randomly
On my tulsa x86-64 machine, kernel 2.6.25-rc5 couldn't boot randomly. Basically, function __enable_runtime forgets to reset rt_rq->rt_throttled to 0. When every cpu is up, per-cpu migration_thread is created and it runs very fast, sometimes to mark the corresponding rt_rq->rt_throttled to 1 very quickly. After all cpus are up, with below calling chain: sched_init_smp => arch_init_sched_domains => build_sched_domains => ... => cpu_attach_domain => rq_attach_root => set_rq_online => ... => _enable_runtime _enable_runtime is called against every rt_rq again, so rt_rq->rt_time is reset to 0, but rt_rq->rt_throttled might be still 1. Later on function do_sched_rt_period_timer couldn't reset it, and all RT tasks couldn't be scheduled to run on that cpu. here is RT task migration_thread which is woken up when a task is migrated to another cpu. Below patch fixes it against 2.6.27-rc5. Signed-off-by: Zhang Yanmin <yanmin_zhang@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
parent
291c54ff76
commit
baf25731e5
|
@ -350,6 +350,7 @@ static void __enable_runtime(struct rq *rq)
|
|||
spin_lock(&rt_rq->rt_runtime_lock);
|
||||
rt_rq->rt_runtime = rt_b->rt_runtime;
|
||||
rt_rq->rt_time = 0;
|
||||
rt_rq->rt_throttled = 0;
|
||||
spin_unlock(&rt_rq->rt_runtime_lock);
|
||||
spin_unlock(&rt_b->rt_runtime_lock);
|
||||
}
|
||||
|
|
Loading…
Reference in a new issue