Re: [PATCH 07/24] locking: Switch to _irq_{disable,enable}() variants in cleanup guards

[Peter Zijlstra <peterz@infradead.org>]

On Mon, Aug 03, 2026 at 06:46:19AM -0700, Boqun Feng wrote:

> > What about the _irqsave() guards?
> > 
> > Is the goal to replace _irqsave guard usage with _irq and then remove
> > the _irqsave guards?
> > 
> 
> Yes, that's the goal. I had that in previous version. However in
> 1abbecd1d2d2 ("sched/fair: Convert cfs bandwidth throttling to use
> guards"), we have a user that explicitly plays with the .flags in guard. 
> Lyude also spotted that too. We could adjust that user to the new API
> (Lyude already has the diff for that) but I decided to simply drop that
> part for now given the current size of the changes. But if you think
> it's a must for merge this, I will add it.

Well, but this new stuff should be able to clean that up, no?

---
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7248,7 +7248,7 @@ static bool distribute_cfs_runtime(struc
  * period the timer is deactivated until scheduling resumes; cfs_b->idle is
  * used to track this state.
  */
-static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun, unsigned long flags)
+static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun)
 	__must_hold(&cfs_b->lock)
 {
 	int throttled;
@@ -7283,10 +7283,10 @@ static int do_sched_cfs_period_timer(str
 	 * This check is repeated as we release cfs_b->lock while we unthrottle.
 	 */
 	while (throttled && cfs_b->runtime > 0) {
-		raw_spin_unlock_irqrestore(&cfs_b->lock, flags);
+		raw_spin_unlock_irq_enable(&cfs_b->lock);
 		/* we can't nest cfs_b->lock while distributing bandwidth */
 		throttled = distribute_cfs_runtime(cfs_b);
-		raw_spin_lock_irqsave(&cfs_b->lock, flags);
+		raw_spin_lock_irq_disable(&cfs_b->lock);
 	}
 
 	/*
@@ -7394,7 +7394,7 @@ static __always_inline void return_cfs_r
 static void do_sched_cfs_slack_timer(struct cfs_bandwidth *cfs_b)
 {
 	/* confirm we're still not at a refresh boundary */
-	scoped_guard(raw_spinlock_irqsave, &cfs_b->lock) {
+	scoped_guard(raw_spinlock_irq, &cfs_b->lock) {
 		u64 runtime = 0, slice = sched_cfs_bandwidth_slice();
 
 		cfs_b->slack_started = false;
@@ -7479,14 +7479,14 @@ static enum hrtimer_restart sched_cfs_pe
 	int idle = 0;
 	int count = 0;
 
-	CLASS(raw_spinlock_irqsave, cfsb_guard)(&cfs_b->lock);
+	guard(raw_spinlock_irq)(&cfs_b->lock);
 
 	for (;;) {
 		overrun = hrtimer_forward_now(timer, cfs_b->period);
 		if (!overrun)
 			break;
 
-		idle = do_sched_cfs_period_timer(cfs_b, overrun, cfsb_guard.flags);
+		idle = do_sched_cfs_period_timer(cfs_b, overrun);
 
 		if (++count > 3) {
 			u64 new, old = ktime_to_ns(cfs_b->period);