Messages in this thread | | | Date | Thu, 21 Oct 2010 16:54:25 +0800 | Subject | Re: Ftrace: can trace kthread? | From | Yong Zhang <> |
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On Thu, Oct 21, 2010 at 4:44 PM, Figo.zhang <zhangtianfei@leadcoretech.com> wrote: > >> > 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 ?
No.
I just echo 0 > tracing_enabled echo function > current_tracer echo 374(pid of flush) > set_ftrace_pid echo 1 > tracing_enabled wait some time echo 0 > tracing_enabled cat trace
So I think this answer your question "could kthread be traced?"
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