Commit e53ada65 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'sched-urgent-2026-02-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull scheduler fix from Ingo Molnar:
 "Fix a regression in the deferrable dl_server code that can cause the
  dl_server to be stuck"

* tag 'sched-urgent-2026-02-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/deadline: Fix 'stuck' dl_server
parents 969b5726 11513542

kernel/sched/deadline.c

+12 −0
Original line number Diff line number Diff line
@@ -1034,6 +1034,12 @@ static void update_dl_entity(struct sched_dl_entity *dl_se) 
			return;

		}



		/*

		 * When [4] D->A is followed by [1] A->B, dl_defer_running

		 * needs to be cleared, otherwise it will fail to properly

		 * start the zero-laxity timer.

		 */

		dl_se->dl_defer_running = 0;

		replenish_dl_new_period(dl_se, rq);

	} else if (dl_server(dl_se) && dl_se->dl_defer) {

		/*
@@ -1655,6 +1661,12 @@ void dl_server_update(struct sched_dl_entity *dl_se, s64 delta_exec) 
 *   dl_server_active = 1;

 *   enqueue_dl_entity()

 *     update_dl_entity(WAKEUP)

 *       if (dl_time_before() || dl_entity_overflow())

 *         dl_defer_running = 0;

 *         replenish_dl_new_period();

 *           // fwd period

 *           dl_throttled = 1;

 *           dl_defer_armed = 1;

 *       if (!dl_defer_running)

 *         dl_defer_armed = 1;

 *         dl_throttled = 1;