Commit 7d2180d9 authored Aug 14, 2024 by Peter Zijlstra

sched: Use set_next_task(.first) where required



Turns out the core_sched bits forgot to use the
set_next_task(.first=true) variant. Notably:

  pick_next_task() := pick_task() + set_next_task(.first = true)

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240813224015.614146342@infradead.org

parent 75b64990

kernel/sched/core.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -6010,7 +6010,7 @@ pick_next_task(struct rq rq, struct task_struct prev, struct rq_flags *rf)
		next = rq->core_pick;
		if (next != prev) {
		put_prev_task(rq, prev);
		set_next_task(rq, next);
		set_next_task_first(rq, next);
		}

		rq->core_pick = NULL;
		@@ -6184,7 +6184,7 @@ pick_next_task(struct rq rq, struct task_struct prev, struct rq_flags *rf)
		}

		out_set_next:
		set_next_task(rq, next);
		set_next_task_first(rq, next);
		out:
		if (rq->core->core_forceidle_count && next == rq->idle)
		queue_core_balance(rq);

kernel/sched/sched.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -2363,6 +2363,10 @@ static inline void set_next_task(struct rq rq, struct task_struct next)
		next->sched_class->set_next_task(rq, next, false);
		}

		static inline void set_next_task_first(struct rq rq, struct task_struct next)
		{
		next->sched_class->set_next_task(rq, next, true);
		}

		/*
		* Helper to define a sched_class instance; each one is placed in a separate