Commit df268382 authored by Tejun Heo's avatar Tejun Heo
Browse files

sched: Restructure sched_class order sanity checks in sched_init() 



Currently, sched_init() checks that the sched_class'es are in the expected
order by testing each adjacency which is a bit brittle and makes it
cumbersome to add optional sched_class'es. Instead, let's verify whether
they're in the expected order using sched_class_above() which is what
matters.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Suggested-by: default avatarPeter Zijlstra <peterz@infradead.org>
Reviewed-by: default avatarDavid Vernet <dvernet@meta.com>
parent 8cce4759

kernel/sched/core.c

+4 −4
Original line number Diff line number Diff line
@@ -8164,12 +8164,12 @@ void __init sched_init(void) 
	int i;



	/* Make sure the linker didn't screw up */

	BUG_ON(&idle_sched_class != &fair_sched_class + 1 ||

	       &fair_sched_class != &rt_sched_class + 1 ||

	       &rt_sched_class   != &dl_sched_class + 1);

#ifdef CONFIG_SMP

	BUG_ON(&dl_sched_class != &stop_sched_class + 1);

	BUG_ON(!sched_class_above(&stop_sched_class, &dl_sched_class));

#endif

	BUG_ON(!sched_class_above(&dl_sched_class, &rt_sched_class));

	BUG_ON(!sched_class_above(&rt_sched_class, &fair_sched_class));

	BUG_ON(!sched_class_above(&fair_sched_class, &idle_sched_class));



	wait_bit_init();