From: Peter Zijlstra <peterz@infradead.org>
Date: Tue, 24 Feb 2026 16:39:08 +0000 (+0100)
Subject: sched: Default enable HRTICK when deferred rearming is enabled
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9213aa4784cf4e63e6d8d30ba71fd61c3d110247;p=thirdparty%2Fkernel%2Flinux.git

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@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260224163431.937531564@kernel.org
---

diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index 136a6584be797..d062284626070 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