sched: Simplify sched_info_on()

The situation around sched_info is somewhat complicated, it is used by
sched_stats and delayacct and, indirectly, kvm.

If SCHEDSTATS=Y (but disabled by default) sched_info_on() is
unconditionally true -- this is the case for all distro kernel configs
I checked.

If for some reason SCHEDSTATS=N, but TASK_DELAY_ACCT=Y, then
sched_info_on() can return false when delayacct is disabled,
presumably because there would be no other users left; except kvm is.

Instead of complicating matters further by accurately accounting
sched_stat and kvm state, simply unconditionally enable when
SCHED_INFO=Y, matching the common distro case.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Link: https://lkml.kernel.org/r/20210505111525.121458839@infradead.org

This commit is contained in:

Peter Zijlstra

2021-05-04 22:43:42 +02:00

parent 4e29fb7098

commit c5895d3f06

3 changed files with 12 additions and 36 deletions

									
										kernel/delayacct.c
									
		-1
	
												View File
												
				@@ -15,7 +15,6 @@

				#include <linux/module.h>

				int delayacct_on __read_mostly = 1;	/* Delay accounting turned on/off */

				EXPORT_SYMBOL_GPL(delayacct_on);

				struct kmem_cache *delayacct_cache;

				static int __init delayacct_setup_disable(char *str)