[tip: sched/hrtick] sched: Default enable HRTICK when deferred rearming is enabled

[tip-bot2 for Peter Zijlstra]

The following commit has been merged into the sched/hrtick branch of tip:

Commit-ID:     9213aa4784cf4e63e6d8d30ba71fd61c3d110247
Gitweb:        https://git.kernel.org/tip/9213aa4784cf4e63e6d8d30ba71fd61c3d110247
Author:        Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate:    Tue, 24 Feb 2026 17:39:08 +01:00
Committer:     Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Fri, 27 Feb 2026 16:40:17 +01:00

sched: Default enable HRTICK when deferred rearming is enabled

The deferred rearm of the clock event device after an interrupt and and
other hrtimer optimizations allow now to enable HRTICK for generic entry
architectures.

This decouples preemption from CONFIG_HZ, leaving only the periodic
load-balancer and various accounting things relying on the tick.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://patch.msgid.link/20260224163431.937531564@xxxxxxxxxx
---
 kernel/sched/features.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index 136a658..d062284 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -63,8 +63,13 @@ SCHED_FEAT(DELAY_ZERO, true)
  */
 SCHED_FEAT(WAKEUP_PREEMPTION, true)
 
+#ifdef CONFIG_HRTIMER_REARM_DEFERRED
+SCHED_FEAT(HRTICK, true)
+SCHED_FEAT(HRTICK_DL, true)
+#else
 SCHED_FEAT(HRTICK, false)
 SCHED_FEAT(HRTICK_DL, false)
+#endif
 
 /*
  * Decrement CPU capacity based on time not spent running tasks