From: Thomas Gleixner <tglx@kernel.org>
Date: Tue, 24 Feb 2026 16:37:14 +0000 (+0100)
Subject: hrtimer: Evaluate timer expiry only once
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=8ffc9ea88136903812448a04127e1ee2c0460f24;p=thirdparty%2Fkernel%2Flinux.git

hrtimer: Evaluate timer expiry only once

No point in accessing the timer twice.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260224163430.409352042@kernel.org
---

diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index 0448ba9a4ab6a..e6f02e9803717 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -810,10 +810,11 @@ static void hrtimer_reprogram(struct hrtimer *timer, bool reprogram)
 {
 	struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
 	struct hrtimer_clock_base *base = timer->base;
-	ktime_t expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
+	ktime_t expires = hrtimer_get_expires(timer);
 
-	WARN_ON_ONCE(hrtimer_get_expires(timer) < 0);
+	WARN_ON_ONCE(expires < 0);
 
+	expires = ktime_sub(expires, base->offset);
 	/*
 	 * CLOCK_REALTIME timer might be requested with an absolute
 	 * expiry time which is less than base->offset. Set it to 0.