Commit a5a25b32 authored by Michal Koutný's avatar Michal Koutný Committed by Peter Zijlstra
Browse files

sched: Always initialize rt_rq's task_group 



rt_rq->tg may be NULL which denotes the root task_group.
Store the pointer to root_task_group directly so that callers may use
rt_rq->tg homogenously.

root_task_group exists always with CONFIG_CGROUPS_SCHED,
CONFIG_RT_GROUP_SCHED depends on that.

This changes root level rt_rq's default limit from infinity to the
value of (originally) global RT throttling.

Signed-off-by: default avatarMichal Koutný <mkoutny@suse.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250310170442.504716-4-mkoutny@suse.com
parent e285313f

kernel/sched/rt.c

+2 −5
Original line number Diff line number Diff line
@@ -89,6 +89,7 @@ void init_rt_rq(struct rt_rq *rt_rq) 
	rt_rq->rt_throttled = 0;

	rt_rq->rt_runtime = 0;

	raw_spin_lock_init(&rt_rq->rt_runtime_lock);

	rt_rq->tg = &root_task_group;

#endif

}
@@ -482,9 +483,6 @@ static inline bool rt_task_fits_capacity(struct task_struct *p, int cpu) 


static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)

{

	if (!rt_rq->tg)

		return RUNTIME_INF;



	return rt_rq->rt_runtime;

}
@@ -1154,7 +1152,6 @@ inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) 
	if (rt_se_boosted(rt_se))

		rt_rq->rt_nr_boosted++;



	if (rt_rq->tg)

	start_rt_bandwidth(&rt_rq->tg->rt_bandwidth);

}

kernel/sched/sched.h

+2 −0
Original line number Diff line number Diff line
@@ -821,6 +821,8 @@ struct rt_rq { 
	unsigned int		rt_nr_boosted;



	struct rq		*rq;

#endif

#ifdef CONFIG_CGROUP_SCHED

	struct task_group	*tg;

#endif

};