From mboxrd@z Thu Jan  1 00:00:00 1970
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Date: Thu, 30 Oct 2008 10:38:00 +0100
From: Jan Kiszka <jan.kiszka@domain.hid>
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Subject: Re: [Xenomai-help] sock_sendmsg() causes crash
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To: Alphan Ulusoy <alphan@domain.hid>
Cc: xenomai@xenomai.org

Alphan Ulusoy wrote:
> Hi all,
>=20
> I' am trying to send small UDP datagrams in a real-time system. I can't
> get a satisfactory performance when I send these packets from a
> userspace Xenomai task using sendto() call.
>=20
> That's why I tried to code a small kernel module to make some
> measurements. However; whenever
>     =95 A xenomai task
>     =95 An alarm function
>     =95 A thread created with kthread_run() form a xenomai task
> that includes the sock_sendmsg() call runs, system crashes. However, if
> a write a regular kernel module, the it works just fine...
>=20
> Below you can find the code and the crash dump.
>=20
> Does anyone have any suggestions? Is there any other way that I can sen=
d
> a UDP packet from a kernel Xenomai task?

I think Philippe already suggested that you should start reading a bit
about the co-kernel model and its implications.

Also, you may want to look at RTnet if you have to send UDP packets
under RT constraints.

Jan

--=20
Siemens AG, Corporate Technology, CT SE 2
Corporate Competence Center Embedded Linux