sched: Create more preempt_count accessors
We need a few special preempt_count accessors:
- task_preempt_count() for when we're interested in the preemption
count of another (non-running) task.
- init_task_preempt_count() for properly initializing the preemption
count.
- init_idle_preempt_count() a special case of the above for the idle
threads.
With these no generic code ever touches thread_info::preempt_count
anymore and architectures could choose to remove it.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-jf5swrio8l78j37d06fzmo4r@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index ee61f5a..0ba4e41 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -983,7 +983,7 @@
* ttwu() will sort out the placement.
*/
WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING &&
- !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE));
+ !(task_preempt_count(p) & PREEMPT_ACTIVE));
#ifdef CONFIG_LOCKDEP
/*
@@ -1723,8 +1723,7 @@
p->on_cpu = 0;
#endif
#ifdef CONFIG_PREEMPT_COUNT
- /* Want to start with kernel preemption disabled. */
- task_thread_info(p)->preempt_count = PREEMPT_DISABLED;
+ init_task_preempt_count(p);
#endif
#ifdef CONFIG_SMP
plist_node_init(&p->pushable_tasks, MAX_PRIO);
@@ -4217,7 +4216,7 @@
raw_spin_unlock_irqrestore(&rq->lock, flags);
/* Set the preempt count _outside_ the spinlocks! */
- task_thread_info(idle)->preempt_count = PREEMPT_ENABLED;
+ init_idle_preempt_count(idle, cpu);
/*
* The idle tasks have their own, simple scheduling class: