我如何知道一个过程的最后一个sched时间

I current run into an issue that a process seems stuck somehow, it just doesn't gets scheduled, the status is always 'S'. I have monitored sched_switch_task trace by debugfs for a while, didn't see the process get scheduled. So I would like to know when is that last time scheduled of this process by kernel? I current run into an issue that a process seem