Messages in this thread | | | Date | Thu, 2 Dec 2004 14:10:02 +0100 | From | Ingo Molnar <> | Subject | Re: [patch] Real-Time Preemption, -RT-2.6.10-rc2-mm3-V0.7.31-19 |
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* Florian Schmidt <mista.tapas@gmx.net> wrote:
> Hmm, i wonder if there's a way to detect non RT behaviour in jackd > clients. I mean AFAIK the only thing allowed for the process callback > of on is the FIFO it waits on to be woken, right? Every other sleeping > is to be considered a bug.
there's such a feature in -RT kernels. If a user process calls:
gettimeofday(1,1);
then the kernel turns 'atomic mode' on. To turn it off, call:
gettimeofday(1,0);
while in atomic-mode, any non-atomic activity (scheduling) will produce a kernel message and a SIGUSR2 sent to the offending process (once, atomic mode has to be re-enabled again for the next message). Preemption by a higher-prio task does not trigger a message/signal.
If you run the client under gdb you should be able to catch the SIGUSR2 signal and then you can see the offending code's backtrace via 'bt'.
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