[EMSCB] L4Linux + IPC

Adam Lackorzynski adam at os.inf.tu-dresden.de
Wed May 3 00:29:05 CEST 2006

On Tue May 02, 2006 at 18:51:39 +0200, Oskar Senft wrote:
> We are using different Deamons running in L4Linux providing IPC services
> to other L4 task. With the most current DROPS CVS checkout, the L4Linux
> user processes freeze completely, as soon as an IPC call is executed
> which causes the process to sleep (eg. DICE IPC server loop).
> The L4Linux kernel seems to run, as it answers Ethernet/IP "ping"
> requests. A connection to a running SSH daemon no longer is possible and
> active SSH connection freeze, too.
> => Only L4Linux userland processes are frozen ?!?

Sounds like scheduling is blocked.

> This did not happen with other version of L4Linux (eg. from January) and
> does not depend on the program we run in L4Linux - it happens with
> different applications that provide IPC services.
> Is this a problem with our settings for L4Env / L4Linux? Or could it be
> a bug in L4Linux?
> Do you have a test program that should run?

Something as simple as

#include <l4/util/util.h>

int main(void)
  while (1)

  return 0;

should work.

Are your user apps in the alien state? (Check with lp in jdb.)

Adam                 adam at os.inf.tu-dresden.de
  Lackorzynski         http://os.inf.tu-dresden.de/~adam/

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