[ltt-dev] Cannot destroy trace

[jerome zh]

2010/5/11 jerome zh <jeromezhr at gmail.com>

> 2010/5/11 Mathieu Desnoyers <compudj at krystal.dyndns.org>
>
>> * jerome zh (jeromezhr at gmail.com) wrote:
>> > Hi all,
>> >
>> > I have modified the original lttng kernel patch to fit my RT-linux
>> patched
>> > 2.6.30 kernel. And IMHO the kernel now works fine.
>> > Everything seems OK until I run "lttctl -D trace1", the process became
>> > "blocking like"(I am not sure if it is blocked).
>> > The last msg printed on the screen is "lttctl: Destroying trace".
>> > Then I added some debug message into the liblttctl.c file. As a result,
>> the
>> > process was "blocked" while executing
>> > *write(fd, op, strlen(op))* in function *lttctl_sendop()*.
>> >
>> > Any advice? Thanks in advance.
>>
>> Can you try with the following patch ?
>>
>>
>> lttng fix rt kernel teardown deadlock
>>
>> LTTng has a teardown bug on RT (deadlock):
>>
>> Deleting a timer (sync) while holding the traces mutex, and the handler
>> takes
>> the same mutex, which leads to a deadlock.
>>
>> Fix this by taking a RCU read lock in the timer (instead of the
>> RT-specific fix
>> using the mutex), and by doing synchronize_rcu() in addition to
>> synchronize_sched() upon updates.
>>
>> ---
>>
>
>
>>
>> --
>>
>> Mathieu Desnoyers
>> Operating System Efficiency R&D Consultant
>> EfficiOS Inc.
>> http://www.efficios.com
>>
>
>
> Thanks!
> I will try this patch and let you know if it works on my board.
>
> --
> Regards,
>
> Jerome
>

Hey Mathieu,

The problem has been solved!

Thanks!


-- 
Regards,

Jerome
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