[Olsr-dev] Bug? "Unknown type: 0, size 1428, from a.b.c.d", OLSR hangs w/ 90% CPU load

Roar Bjørgum Rotvik (spam-protected)
Mon Jan 21 09:03:02 CET 2008

Jo-Philipp Wich wrote:
> Hash: SHA1
> Hi,
> sorry for the late reply but I had some difficulties reproducing the
> problem.
> I haven't managed it to produce a gcore dump (I think you meant the
> gcore command in gdb). After attaching gdbserver to the running olsrd
> process the "gcore" command on the gdb client produced the message
> "Cannot create a core file" and I don't know how to fix this problem.

To make a crashing application create a core-file in linux/unix, you must first make sure 
that the environment is set for creating core-file.

Run "ulimit -c". On my machine this gives "0". This means that the max allowed core file 
size is 0 bytes, i.e. no core file is allowed to be created.

To allow a core file to be created, run "ulimit -c unlimited" (or a byte size instead of 
unlimited). This command must be run in the shell where you start olsrd from, it only 
applies to the shell you run the command in (you may also set this in /etc/profile.d/* or 
in ~/.bash_profile or similar to apply always and in all shells, but that is another story).

Then you only have to run the application and reproduce the problem making the application 
crash and a core file will be created. No need to involve gdb at all to create core file, 
the OS will do it for you when the application crashes. Please notice that on some 
OS/Linux distros the corefile will have the PID number appended to the core file name, so 
it is named something like "core.13456" or similar.

Roar Bjørgum Rotvik

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