| Subject | Re: process 'stuck' at exit. | From | Darren Hart <> | Date | Tue, 10 Dec 2013 13:25:34 -0800 |
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On Tue, 2013-12-10 at 15:55 -0500, Dave Jones wrote: > On Tue, Dec 10, 2013 at 09:34:24PM +0100, Thomas Gleixner wrote: > > > > > PS: Oleg - the whole thread is on lkml. Ping me if you need more context. > > > > > > btw, I've left the machine in that state, and will for as long as necesary > > > in case someone has any ideas for further tracing experiments. > > > > Can you gather a trace with the function tracer? That will tell us > > what the thing is actually doing. > > Feed me command lines, and I'll see what I can do. > > Dave >
So let's see if we can determine the call chain inside futex_requeue, if there is one. We want to see if we are calling the following functions:
futex.c: free_pi_state futex.c: get_futex_value_locked futex.c: futex_proxy_trylock_atomic futex.c: lookup_pi_state futex.c: fault_in_user_writeable
I'm hoping we can make use of ftrace here?
Consider:
$ trace-cmd record -P <PID> -p function -l '*futex*'
And to try outside of futex:
$ trace-cmd record -P <PID> -p function
Then ^C after a few seconds. The trace will be in trace.dat
-- Darren Hart Intel Open Source Technology Center Yocto Project - Linux Kernel
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