Re: Ftrace: can trace kthread?

Figo.zhang
2010-10-21T08:48:47Z

> > i try by set_ftrace_pid, it also can't ftrace the kswapd.
>
> Are you sure kswapd got chance to run on your system?
>
> BTW, I can successfully trace bdi_writeback_thread,
> # tracer: function
> #
> # TASK-PID CPU# TIMESTAMP FUNCTION
> # | | | | |
> flush-8:0-374 [000] 600743.828496: finish_task_switch <-schedule
> flush-8:0-374 [000] 600743.828498: perf_event_task_sched_in
> <-finish_task_switch
> flush-8:0-374 [000] 600743.828498: del_timer_sync <-schedule_timeout
> flush-8:0-374 [000] 600743.828499: try_to_del_timer_sync
> <-del_timer_sync
> flush-8:0-374 [000] 600743.828499: lock_timer_base
> <-try_to_del_timer_sync
> flush-8:0-374 [000] 600743.828499: _spin_lock_irqsave <-lock_timer_base
> flush-8:0-374 [000] 600743.828500: _spin_unlock_irqrestore
> <-try_to_del_timer_sync
> flush-8:0-374 [000] 600743.828500: kthread_should_stop
> <-bdi_writeback_task

are you use my scprit to trace the bdi_writeback_thread ?