hanging tasks - information about task state etc.

[Joel Sherrill]

Peter Mueller wrote:
> 
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> Hi Joel,
> 
> yes I'm using m68k (variant of efi332) and the snapshop 20020628.

Hmmm... a 332 is a cpu32 which I think was one of the variants 
exhibiting this behavior.  

> What is PR267? Is there a description of this bug and its solution (btw.
> is there a bug tracking system like bugzilla available for rtems?)?

Yes.  We have been using GNATS for a while now (we are over PR300 now).

http://www.oarcorp.com/cgi-bin/gnatsweb.pl 

User/Password == guest/guest

> In what snapshot is the PR267 fixed?

Based upon the ChangeLog in score/cpu/m68k, it looks like any snapshot
newer than 26 Aug 2002.

> Thanks,
> Peter
> 
> On Mon, 27 Jan 2003 08:18:45 -0600
> Joel Sherrill <joel.sherrill at OARcorp.com> wrote:
> 
> >
> > Peter .. what CPU are you using?  This sounds a lot like the behavior
> > people got before an m68k specific fix went in.  It was tracked
> > as PR267 and CVS shows the last fix as back in August.  Any chance
> > you are using an m68k and something that old?
> >
> > Thomas Doerfler wrote:
> > >
> > > Hello Peter,
> > >
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> > > > Hi Joel, Thomas,
> > > >
> > > > thanks for your replies. dump_tasks finally helped me to find one
> > > > problem. A task waiting for an event that gets usually sent from an
> > > > irq. It turned out that the hardware triggering the irq hangs
> > > > sometimes so that the irq is missing and my task waits forever.
> > >
> > > Normally I know things the other way round: Software guys find
> > > "hardware errors" and later on the hardware guys find out that
> > > the hardware was not initialized/used properly by the
> > > software... :-)
> > >
> > > >
> > > > The other thing is not solved. Here I like to ask again for your
> > > > advice.. One of my tasks handles serial input. After my system runs
> > > > for a while this task seems to get not scheduled anymore even if the
> > > > system is not fully loaded. The task state is 8->STATES_DELAYING
> > > > which means wait for timeout. This is ok because my old efi332
> > > > serial driver polls the rcv buffer to check if there is new data and
> > > > waits for some ticks if nothing is there. Could it be possible that
> > > > rtems_task_wake_after does not return for any reason?
> > >
> > > Hm, the only reasons I could think of would be:
> > >
> > > - Interrupts for System Tick do no longer occure, because: The
> > > interrupt is blocked, the timer has stopped or something
> > > similar. Can you check, whether the system tick still occures
> > > when your task hangs? You are working with a 68332 and BDM?
> > > Stop the system when your task hangs and set a breakpoint into
> > > the timer interrupt function. Does it get hit still?
> > >
> > > - You call "rtems_task_wake_after" with a VERY long delay...
> > > (quite improbable)
> > >
> > > maybe this helps a bit...
> > > Thomas.
> > >
> > > >
> > > > Thanks,
> > > > Peter
> > > >
> > > > >
> > > > > Peter, the gdb script I have posted a couple of times is a good
> > > > > start on seeing what the tasks in the system are up to.  I would
> > > > > like to see the gdb script eventually enhanced so that it could
> > > > > give you some details
> > > > > like decoding the task state into English and know that if in
> > > > > certain states,
> > > > > that Wait.id is what the task is waiting on.
> > > > >
> > > > > > Thanks,
> > > > > > Peter
> > > > > >
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> > >
> > > --------------------------------------------
> > > IMD Ingenieurbuero fuer Microcomputertechnik
> > > Thomas Doerfler           Herbststrasse 8
> > > D-82178 Puchheim          Germany
> > > email:    Thomas.Doerfler at imd-systems.de
> > > PGP public key available at: http://www.imd-
> > > systems.de/pgp_keys.htm
> >
> > --
> > Joel Sherrill, Ph.D.             Director of Research & Development
> > joel at OARcorp.com                 On-Line Applications Research
> > Ask me about RTEMS: a free RTOS  Huntsville AL 35805
> > Support Available                (256) 722-9985
> >
> 
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-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel at OARcorp.com                 On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
Support Available                (256) 722-9985