[nos-bbs] headless jnos consuming 100% CPU

George [ham] VerDuin k8rra at ameritech.net
Mon Mar 21 21:11:16 EDT 2011

Hi harry.

On 03/21/2011 07:29 PM, Harry Stone wrote:
> When I compile JNOS with headless defined, it compiles fine and also 
> runs fine until I start it and then log out of the machine.  After I 
> log out, JNOS consumes 100% of cpu.  It seems like it still runs fine, 
> although the machine is bogged down.
I've not tried " define headless" since I like the option to 
connect/disconnect from the sysop console using screen to keep the I/O 
path alive.  For me, the "@" access to sysop functions is second best.  
However I too have seen 100% just as you describe.  In my case I can 
demonstrate that some time after unplugging the TNC from the host, that 
the CPU does saturate.  Yes -- other responses continue OK / perhaps a 
little delayed.

I've not determined where the infinite loop is, perhaps I should to make 
a stab at fixing the issue.  I *suspect* the issue for you is the same, 
and it is related to some buffer that will no longer empty to the device 
it is supposed to be driving.  Because the sysop console is very active 
I suspect the time to fill it up is shorter than my ttySx device, and 
worse > the headless option should stop filling the buffer.  And of 
course this paragraph is a WAG on my part. You should know that others 
on this reflector have reported "no saturation", even after disabling 
the TNC.

> Is there a #define I can change in the config header to make it spit 
> out some debug info?  Please let me know if there's anything I can do 
> to help troubleshoot this.
The gdb seems to be the preferred tool.  The standard jnos delivery 
includes whatever gdb needs for hooks and references.  They can be 
stripped out after you are happy if you need to save object module bytes.

Best of luck

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