sched: do not normalize kernel threads via SysRq-N

do not normalize kernel threads via SysRq-N: the migration threads,
softlockup threads, etc. might be essential for the system to
function properly. So only zap user tasks.

pointed out by Andi Kleen.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Ingo Molnar 2007-10-15 17:00:18 +02:00
parent 1666703af9
commit 178be79348

View File

@ -365,15 +365,6 @@ static inline int cpu_of(struct rq *rq)
#endif
}
static inline int is_migration_thread(struct task_struct *p, struct rq *rq)
{
#ifdef CONFIG_SMP
return p == rq->migration_thread;
#else
return 0;
#endif
}
/*
* Update the per-runqueue clock, as finegrained as the platform can give
* us, but without assuming monotonicity, etc.:
@ -6563,6 +6554,12 @@ void normalize_rt_tasks(void)
read_lock_irq(&tasklist_lock);
do_each_thread(g, p) {
/*
* Only normalize user tasks:
*/
if (!p->mm)
continue;
p->se.exec_start = 0;
#ifdef CONFIG_SCHEDSTATS
p->se.wait_start = 0;
@ -6584,8 +6581,7 @@ void normalize_rt_tasks(void)
spin_lock_irqsave(&p->pi_lock, flags);
rq = __task_rq_lock(p);
if (!is_migration_thread(p, rq))
normalize_task(rq, p);
normalize_task(rq, p);
__task_rq_unlock(rq);
spin_unlock_irqrestore(&p->pi_lock, flags);