Mary E. Plath ([log in to unmask]) wrote:
: We are a new mpe/ix 4.0 shop.
: The other day we had a batch job use excessive amounts of
: cpu.  Another batch job running at the same time was
: starved for cpu and ran much longer than usual.
: When the first job was suspended the second one was able to
: finish.
: My question is:  what, if anything, can be done to
: prevent thissort of situation.
You may shorten the quantum for the DQ from 2000 millisec to something
less (like 400 or 200). Also, the Oscillate option may be used rather
than the default DECAY.  See the TUNE command in help.
For example, TUNE ;DQ=,,400,400,oscillate,200  should improve the world.
Use SHOWQ;STATUS to see the tune parameter values before and AFTER
any tune command.  The speed of your processor will impact the quantum,
faster machines generally need shorter quantums.  Do not go too low
(100?) as the overhead of switching processes can become excessive.
 
I frequently use TUNE ;CQ=,,50,1000,decay,100 to guarantee a minimum
quantum for interactive users and to set a lower limit for CPU hogs.
That is not your problem, but the concept is the same.
--
 James Overman HP Support Technology Lab  Roseville, CA