The following commit has been merged into the sched/hrtick branch of tip:
Commit-ID: 3601a1d85028d7d479e1571419174fc3334f58f5
Gitweb: https://git.kernel.org/tip/3601a1d85028d7d479e1571419174fc3334f58f5
Author: Thomas Gleixner <tglx@kernel.org>
AuthorDate: Tue, 24 Feb 2026 17:38:42 +01:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Fri, 27 Feb 2026 16:40:15 +01:00
hrtimer: Optimize for_each_active_base()
Give the compiler some help to emit way better code.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260224163431.599804894@kernel.org
---
kernel/time/hrtimer.c | 20 ++++----------------
1 file changed, 4 insertions(+), 16 deletions(-)
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index b0e7e29..d1e5848 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -529,22 +529,10 @@ static inline void debug_activate(struct hrtimer *timer, enum hrtimer_mode mode,
trace_hrtimer_start(timer, mode, was_armed);
}
-static struct hrtimer_clock_base *
-__next_base(struct hrtimer_cpu_base *cpu_base, unsigned int *active)
-{
- unsigned int idx;
-
- if (!*active)
- return NULL;
-
- idx = __ffs(*active);
- *active &= ~(1U << idx);
-
- return &cpu_base->clock_base[idx];
-}
-
-#define for_each_active_base(base, cpu_base, active) \
- while ((base = __next_base((cpu_base), &(active))))
+#define for_each_active_base(base, cpu_base, active) \
+ for (unsigned int idx = ffs(active); idx--; idx = ffs((active))) \
+ for (bool done = false; !done; active &= ~(1U << idx)) \
+ for (base = &cpu_base->clock_base[idx]; !done; done = true)
#if defined(CONFIG_NO_HZ_COMMON)
/*