Date: Mon, 2 Feb 1998 10:22:40 -0600 (CST) From: Damon Permezel <dap@damon.com> To: dap@damon.com (Damon Permezel) Cc: jb@cimlogic.com.au, nate@mt.sri.com, SSANKARA.IN.oracle.com.ofcmail@in.oracle.com, freebsd-java@FreeBSD.ORG Subject: Re: TimeSlicing in JVM Message-ID: <199802021622.KAA06376@damon.com> In-Reply-To: <199802021611.KAA06331@damon.com> from Damon Permezel at "Feb 2, 98 10:11:27 am"
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"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. Where is that FM?
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