Commit 2c8d046d authored by Tejun Heo's avatar Tejun Heo
Browse files

sched: Add normal_policy() 



A new BPF extensible sched_class will need to dynamically change how a task
picks its sched_class. For example, if the loaded BPF scheduler progs fail,
the tasks will be forced back on CFS even if the task's policy is set to the
new sched_class. To support such mapping, add normal_policy() which wraps
testing for %SCHED_NORMAL. This doesn't cause any behavior changes.

v2: Update the description with more details on the expected use.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Reviewed-by: default avatarDavid Vernet <dvernet@meta.com>
Acked-by: default avatarJosh Don <joshdon@google.com>
Acked-by: default avatarHao Luo <haoluo@google.com>
Acked-by: default avatarBarret Rhoden <brho@google.com>
parent 96fd6c65

kernel/sched/fair.c

+1 −1
Original line number Diff line number Diff line
@@ -8391,7 +8391,7 @@ static void check_preempt_wakeup_fair(struct rq *rq, struct task_struct *p, int 
	 * Batch and idle tasks do not preempt non-idle tasks (their preemption

	 * is driven by the tick):

	 */

	if (unlikely(p->policy != SCHED_NORMAL) || !sched_feat(WAKEUP_PREEMPTION))

	if (unlikely(!normal_policy(p->policy)) || !sched_feat(WAKEUP_PREEMPTION))

		return;



	find_matching_se(&se, &pse);

kernel/sched/sched.h

+6 −1
Original line number Diff line number Diff line
@@ -192,9 +192,14 @@ static inline int idle_policy(int policy) 
	return policy == SCHED_IDLE;

}



static inline int normal_policy(int policy)

{

	return policy == SCHED_NORMAL;

}



static inline int fair_policy(int policy)

{

	return policy == SCHED_NORMAL || policy == SCHED_BATCH;

	return normal_policy(policy) || policy == SCHED_BATCH;

}



static inline int rt_policy(int policy)