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commite895f8e291upstream. When testing softirq based hrtimers on an ARM32 board, with high resolution mode and NOHZ inactive, softirq based hrtimers fail to expire after being moved away from an offline CPU: CPU0 CPU1 hrtimer_start(..., HRTIMER_MODE_SOFT); cpu_down(CPU1) ... hrtimers_cpu_dying() // Migrate timers to CPU0 smp_call_function_single(CPU0, returgger_next_event); retrigger_next_event() if (!highres && !nohz) return; As retrigger_next_event() is a NOOP when both high resolution timers and NOHZ are inactive CPU0's hrtimer_cpu_base::softirq_expires_next is not updated and the migrated softirq timers never expire unless there is a softirq based hrtimer queued on CPU0 later. Fix this by removing the hrtimer_hres_active() and tick_nohz_active() check in retrigger_next_event(), which enforces a full update of the CPU base. As this is not a fast path the extra cost does not matter. [ tglx: Massaged change log ] Fixes:5c0930ccaa("hrtimers: Push pending hrtimers away from outgoing CPU earlier") Co-developed-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250805081025.54235-1-wangxiongfeng2@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>