Commit edf005fa authored by Tejun Heo's avatar Tejun Heo
Browse files

sched_ext: Improve SCX_KF_DISPATCH comment 



The comment for SCX_KF_DISPATCH was incomplete and didn't explain that
ops.dispatch() may temporarily release the rq lock, allowing ENQUEUE and
SELECT_CPU operations to be nested inside DISPATCH contexts.

Update the comment to clarify this nesting behavior and provide better
context for when these operations can occur within dispatch.

Acked-by: default avatarAndrea Righi <arighi@nvidia.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent c8191ee8

include/linux/sched/ext.h

+5 −1
Original line number Diff line number Diff line
@@ -108,7 +108,11 @@ enum scx_kf_mask { 
	SCX_KF_UNLOCKED		= 0,	  /* sleepable and not rq locked */

	/* ENQUEUE and DISPATCH may be nested inside CPU_RELEASE */

	SCX_KF_CPU_RELEASE	= 1 << 0, /* ops.cpu_release() */

	/* ops.dequeue (in REST) may be nested inside DISPATCH */

	/*

	 * ops.dispatch() may release rq lock temporarily and thus ENQUEUE and

	 * SELECT_CPU may be nested inside. ops.dequeue (in REST) may also be

	 * nested inside DISPATCH.

	 */

	SCX_KF_DISPATCH		= 1 << 1, /* ops.dispatch() */

	SCX_KF_ENQUEUE		= 1 << 2, /* ops.enqueue() and ops.select_cpu() */

	SCX_KF_SELECT_CPU	= 1 << 3, /* ops.select_cpu() */