Hi Ming On 05/02/2018 11:33 AM, Ming Lei wrote: > No, there isn't such race, the 'mod_timer' doesn't make a difference > because 'q->timeout_off' will be visible in new work func after > cancel_work_sync() returns. So even the timer is expired, work func > still returns immediately. Yes, you are right. even if timer is setup , but the timeout work will return. Thanks Jianchao