Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!wuarchive!psuvax1!husc6!encore!pinocchio!peralta
From: peralta@pinocchio.Encore.COM (Rick Peralta)
Newsgroups: comp.unix.wizards
Subject: Re: What new system calls do you want in BSD?
Summary: implement weighted usage of I/O, memory and CPU usage
Message-ID: <11102@encore.Encore.COM>
Date: 8 Feb 90 21:14:11 GMT
Sender: news@Encore.COM
Reply-To: peralta@pinocchio.UUCP (Rick Peralta)
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Lines: 23

How about resource weighting.
For example:
	. have the free memory weight be tunable
	  That is to say instead of taking a compile time
	  value (maybe 10% free) for when to start flushing
	  things to swap, accept changes from the sysadmin.
	. memory usage priority (even on the page level)
	  lock this page in memory, this one is largely filler, etc.
	. I/O priority, get my I/O done ASAP or after everyone else
	. heavy CPU priority (more than just nice)
	  this thread is to be done at hardware interrupt level x,
	  after hardware interrupts, as part of the idle loop

Things like sync could be placed in the lowest priority loop and called
more frequently.  Things like servers that tend to be bottlenecks and
don't consume lots of resources could be placed in the upper categories.
Kernel code running in user space (whoops, I for got to mentin that)
could be exectued in satisfactory time for most driver applications.
Things like compiles could get high memory priority and things like
Emacs could get a lower memory priority but higher I/O priority.


 - Rick "Just a fwe stray synapses..."