From: Peter Zijlstra <peterz@infradead.org>
Date: Tue, 28 Oct 2025 14:04:17 +0000 (+0100)
Subject: Merge branch 'linus/master' into sched/core, to resolve conflict
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=977b9a00541929973fddfbc2f5e932469f7cdc81;p=thirdparty%2Flinux.git

Merge branch 'linus/master' into sched/core, to resolve conflict

Conflicts:
	kernel/sched/ext.c

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---

977b9a00541929973fddfbc2f5e932469f7cdc81
diff --cc kernel/sched/ext.c
index 49f4a9e763486,ecb251e883eab..b063444dc003f
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@@ -2298,22 -2368,41 +2332,23 @@@ static struct task_struct *first_local_
  					struct task_struct, scx.dsq_list.node);
  }
  
 -static struct task_struct *pick_task_scx(struct rq *rq)
 +static struct task_struct *pick_task_scx(struct rq *rq, struct rq_flags *rf)
  {
  	struct task_struct *prev = rq->curr;
 +	bool keep_prev, kick_idle = false;
  	struct task_struct *p;
 -	bool keep_prev = rq->scx.flags & SCX_RQ_BAL_KEEP;
 -	bool kick_idle = false;
  
 -	/*
 -	 * WORKAROUND:
 -	 *
 -	 * %SCX_RQ_BAL_KEEP should be set iff $prev is on SCX as it must just
 -	 * have gone through balance_scx(). Unfortunately, there currently is a
 -	 * bug where fair could say yes on balance() but no on pick_task(),
 -	 * which then ends up calling pick_task_scx() without preceding
 -	 * balance_scx().
 -	 *
 -	 * Keep running @prev if possible and avoid stalling from entering idle
 -	 * without balancing.
 -	 *
 -	 * Once fair is fixed, remove the workaround and trigger WARN_ON_ONCE()
 -	 * if pick_task_scx() is called without preceding balance_scx().
 -	 */
 -	if (unlikely(rq->scx.flags & SCX_RQ_BAL_PENDING)) {
 -		if (prev->scx.flags & SCX_TASK_QUEUED) {
 -			keep_prev = true;
 -		} else {
 -			keep_prev = false;
 -			kick_idle = true;
 -		}
 -	} else if (unlikely(keep_prev &&
 -			    prev->sched_class != &ext_sched_class)) {
 -		/*
 -		 * Can happen while enabling as SCX_RQ_BAL_PENDING assertion is
 -		 * conditional on scx_enabled() and may have been skipped.
 -		 */
 +	rq_modified_clear(rq);
 +	rq_unpin_lock(rq, rf);
 +	balance_one(rq, prev);
 +	rq_repin_lock(rq, rf);
++	maybe_queue_balance_callback(rq);
 +	if (rq_modified_above(rq, &ext_sched_class))
 +		return RETRY_TASK;
 +
 +	keep_prev = rq->scx.flags & SCX_RQ_BAL_KEEP;
 +	if (unlikely(keep_prev &&
 +		     prev->sched_class != &ext_sched_class)) {
  		WARN_ON_ONCE(scx_enable_state() == SCX_ENABLED);
  		keep_prev = false;
  	}