kthread: Add __kthread_should_park()

kthread_should_park() is used to check if the calling kthread ('current')
should park, but there is no function to check whether an arbitrary kthread
should be parked. The latter is required to plug a CPU hotplug race vs. a
parking ksoftirqd thread.

The new __kthread_should_park() receives a task_struct as parameter to
check if the corresponding kernel thread should be parked.

Call __kthread_should_park() from kthread_should_park() to avoid code
duplication.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Stephen Boyd <swboyd@chromium.org>
Link: https://lkml.kernel.org/r/20190128234625.78241-2-mka@chromium.org
This commit is contained in:
Matthias Kaehlcke 2019-01-28 15:46:24 -08:00 committed by Thomas Gleixner
parent c2da3f1b71
commit 0121805d9d
2 changed files with 8 additions and 1 deletions

View File

@ -56,6 +56,7 @@ void kthread_bind_mask(struct task_struct *k, const struct cpumask *mask);
int kthread_stop(struct task_struct *k);
bool kthread_should_stop(void);
bool kthread_should_park(void);
bool __kthread_should_park(struct task_struct *k);
bool kthread_freezable_should_stop(bool *was_frozen);
void *kthread_data(struct task_struct *k);
void *kthread_probe_data(struct task_struct *k);

View File

@ -101,6 +101,12 @@ bool kthread_should_stop(void)
}
EXPORT_SYMBOL(kthread_should_stop);
bool __kthread_should_park(struct task_struct *k)
{
return test_bit(KTHREAD_SHOULD_PARK, &to_kthread(k)->flags);
}
EXPORT_SYMBOL_GPL(__kthread_should_park);
/**
* kthread_should_park - should this kthread park now?
*
@ -114,7 +120,7 @@ EXPORT_SYMBOL(kthread_should_stop);
*/
bool kthread_should_park(void)
{
return test_bit(KTHREAD_SHOULD_PARK, &to_kthread(current)->flags);
return __kthread_should_park(current);
}
EXPORT_SYMBOL_GPL(kthread_should_park);