GDB & SCHED_RR

GDB & SCHED_RR

[Oldham, Adam]

Hey people....

I have a Linux 2.4.8 system runnign GDB 5.0.  I am trying to debug a program
that starts all its threads using SCHED_RR and running the threads a
different priorities.

I wanted to ask this to see if I could get a good answer before writing up
any kind of bug.  So, is GDB supposed to be able to debug executables that
have Real Time threads?  Debug is a vague word, but my problem is that, when
GDB is started and my executable is run through GDB, it appears as though
the thread priorities are not being set up correctly.  The threads do not
seem to execute in the same order as when the executable is run standalone.

Thanks,
Adam Oldham

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C. Adam Oldham              Marconi Commerce Systems Inc.
Software Engineer           7300 West Friendly Ave.
adam.oldham@marconi.com     Greensboro, NC 27420-2087
Phone : 336.547.5952        Fax   : 336.547.5079
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Re: GDB & SCHED_RR

[Daniel Jacobowitz]

On Wed, Jan 02, 2002 at 07:54:11AM -0500, Oldham, Adam wrote:
> Hey people....
> 
> I have a Linux 2.4.8 system runnign GDB 5.0.  I am trying to debug a program
> that starts all its threads using SCHED_RR and running the threads a
> different priorities.
> 
> I wanted to ask this to see if I could get a good answer before writing up
> any kind of bug.  So, is GDB supposed to be able to debug executables that
> have Real Time threads?  Debug is a vague word, but my problem is that, when
> GDB is started and my executable is run through GDB, it appears as though
> the thread priorities are not being set up correctly.  The threads do not
> seem to execute in the same order as when the executable is run standalone.

I'd certainly not expect them to be.

Thread debugging is intrusive.  We can (perhaps) make it a little less
obtrusive than it is currently; but the presence of a debugger is
noticeable even to basic multithreaded applications.

-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer