diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2014-09-21 21:33:38 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2014-09-24 14:47:03 +0200 |
| commit | 3472eaa1f12e217e2b8b0ef658ff861b2308cbbd (patch) | |
| tree | c231d968cc0a6a696ae8f3e008f979899bf52b45 /kernel/sched | |
| parent | 8651c65844e93af44554272b7e0d2b142837b244 (diff) | |
sched: normalize_rt_tasks(): Don't use _irqsave for tasklist_lock, use task_rq_lock()
1. read_lock(tasklist_lock) does not need to disable irqs.
2. ->mm != NULL is a common mistake, use PF_KTHREAD.
3. The second ->mm check can be simply removed.
4. task_rq_lock() looks better than raw_spin_lock(&p->pi_lock) +
__task_rq_lock().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140921193338.GA28621@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/core.c | 16 |
1 files changed, 6 insertions, 10 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 0abfb7ec9e62..d65566d07fcf 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7220,12 +7220,12 @@ void normalize_rt_tasks(void) unsigned long flags; struct rq *rq; - read_lock_irqsave(&tasklist_lock, flags); + read_lock(&tasklist_lock); for_each_process_thread(g, p) { /* * Only normalize user tasks: */ - if (!p->mm) + if (p->flags & PF_KTHREAD) continue; p->se.exec_start = 0; @@ -7240,20 +7240,16 @@ void normalize_rt_tasks(void) * Renice negative nice level userspace * tasks back to 0: */ - if (task_nice(p) < 0 && p->mm) + if (task_nice(p) < 0) set_user_nice(p, 0); continue; } - raw_spin_lock(&p->pi_lock); - rq = __task_rq_lock(p); - + rq = task_rq_lock(p, &flags); normalize_task(rq, p); - - __task_rq_unlock(rq); - raw_spin_unlock(&p->pi_lock); + task_rq_unlock(rq, p, &flags); } - read_unlock_irqrestore(&tasklist_lock, flags); + read_unlock(&tasklist_lock); } #endif /* CONFIG_MAGIC_SYSRQ */ |