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From: Damon Permezel <dap@damon.com>
Message-Id: <199802021623.KAA06394@damon.com>
Subject: Re: TimeSlicing in  JVM
In-Reply-To: <199802021622.KAA06376@damon.com> from Damon Permezel at "Feb 2, 98 10:22:40 am"
To: dap@fubar.damon.com (Damon Permezel)
Date: Mon, 2 Feb 1998 10:23:52 -0600 (CST)
Cc: dap@damon.com, jb@cimlogic.com.au, nate@mt.sri.com,
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"Damon Permezel sez: "
> "Damon Permezel sez: "
> > "John Birrell sez: "
> > > Nate Williams wrote:
> > > > I also remember thinking seriously about this problem after reading a
> > > > Java threads book, and they brought up another point that I can't recall
> > > > right now that was also one of those 'syscall' types of problems.  If I
> > > > remember or find it I'll send something to the list.
> > > 
> > > It might be a scheduler issue. Like the one where a lower priority
> > > thread locks a resource that a higher priority thread needs, but the
> > > lower priority thread can't get enough CPU time to finish using the
> > > resource. libc_r deals with this by using an incremental priority
> > > that is reset when a thread gets to run, but is incremented the
> > > longer it is ready to run but prevented from running. Eventually
> > > the lower priority thread has a higher effective priority and gets
> > > to see its name in lights.
> > > 
> > 
> > The green_threads scheduler has priority inversion.
> > Not sure if it works.  This is one of the issues of turning on time slicing.
> > Perhaps there were many good reasons why it is off for green_threads....
> > 
> > I guess one of us should scrutinize the code, see if we really think
> > turning on the timeslicing will work (at the basic level, without too
> > much associated hacking) and then turn it on.
> 
> Silly me!
> You can just use:
> 
> 	java -ts100 ....
> 
> to turn on time slicing with green threads.
> From an initial sniff, I see that there is not a timeslicer thread running.
> 
I think you mean "now", rather than not, no?

> Where is that FM?
> 
Beats me.