Commit 12494e5e authored by Zqiang's avatar Zqiang Committed by Tejun Heo
Browse files

sched_ext: Fix some comments in ext.c 



This commit update balance_scx() in the comments to balance_one().

Signed-off-by: default avatarZqiang <qiang.zhang@linux.dev>
Reviewed-by: default avatarAndrea Righi <arighi@nvidia.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent b0101ccb

kernel/sched/ext.c

+5 −5
Original line number Diff line number Diff line
@@ -1577,7 +1577,7 @@ static bool dequeue_task_scx(struct rq *rq, struct task_struct *p, int deq_flags 
	 *

	 * @p may go through multiple stopping <-> running transitions between

	 * here and put_prev_task_scx() if task attribute changes occur while

	 * balance_scx() leaves @rq unlocked. However, they don't contain any

	 * balance_one() leaves @rq unlocked. However, they don't contain any

	 * information meaningful to the BPF scheduler and can be suppressed by

	 * skipping the callbacks if the task is !QUEUED.

	 */
@@ -2372,7 +2372,7 @@ static void switch_class(struct rq *rq, struct task_struct *next) 
	 * preempted, and it regaining control of the CPU.

	 *

	 * ->cpu_release() complements ->cpu_acquire(), which is emitted the

	 *  next time that balance_scx() is invoked.

	 *  next time that balance_one() is invoked.

	 */

	if (!rq->scx.cpu_released) {

		if (SCX_HAS_OP(sch, cpu_release)) {
@@ -2478,7 +2478,7 @@ do_pick_task_scx(struct rq *rq, struct rq_flags *rf, bool force_scx) 
	}



	/*

	 * If balance_scx() is telling us to keep running @prev, replenish slice

	 * If balance_one() is telling us to keep running @prev, replenish slice

	 * if necessary and keep running @prev. Otherwise, pop the first one

	 * from the local DSQ.

	 */
@@ -4025,7 +4025,7 @@ static DEFINE_TIMER(scx_bypass_lb_timer, scx_bypass_lb_timerfn); 
 *

 * - ops.dispatch() is ignored.

 *

 * - balance_scx() does not set %SCX_RQ_BAL_KEEP on non-zero slice as slice

 * - balance_one() does not set %SCX_RQ_BAL_KEEP on non-zero slice as slice

 *   can't be trusted. Whenever a tick triggers, the running task is rotated to

 *   the tail of the queue with core_sched_at touched.

 *
@@ -6069,7 +6069,7 @@ __bpf_kfunc bool scx_bpf_dsq_move_to_local(u64 dsq_id) 
		/*

		 * A successfully consumed task can be dequeued before it starts

		 * running while the CPU is trying to migrate other dispatched

		 * tasks. Bump nr_tasks to tell balance_scx() to retry on empty

		 * tasks. Bump nr_tasks to tell balance_one() to retry on empty

		 * local DSQ.

		 */

		dspc->nr_tasks++;