octave in uninterruptible state on Alpha

[Francesco Potorti`]

Jim Van Zandt <address@hidden> writes:

   Francesco Potorti` <address@hidden> writes:
   >one day octave
   >stopped and refused to show its first prompt.  A ps revealed that
   >octave was there, in uninterruptible state.

   Neither you nor the superuser can do "kill -9 XXXX" where XXXX is the
   process ID?  I thought that was a sure kill.

Unfortunately kill -9 can do no good.  There are times when a process
waits for a resource in the kernel, inside a critical region, when it
cannot receive signals.  The signals are queued for it to be received
when it exits from the uninterruptible state.  The ps output usually
marks those processes with the letter U.

   I assume Octave hangs waiting for some resource to become available.
   A pty (pseudo-terminal), maybe.  

Ding!  Could be!  I'll try to convince the sysadmin of the Alpha.

   Another approach is to install strace, and run Octave under that.
   That should tell you which system request hangs.

There in no strace on Alpha.  Don't know if it can be installed.


Evan Thomas <address@hidden> writes:

   I have seen the same thing on Linux. Kill -9 pid will remove it for
   me.

It's not the same, then :-(

   In my case octave was in hard CPU loop as well.

No, these are uninterruptible processes, they eat no CPU and their RSS
is 0.

Thank you.  I'll let you know how it goes.
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