Date: Tue, 15 Sep 1998 06:32:13 -0500 (EST) From: Alfred Perlstein <bright@hotjobs.com> To: Mike Smith <mike@smith.net.au> Cc: freebsd-current@FreeBSD.ORG Subject: Re: Download of FreeBSD 3.0-SNAP Message-ID: <Pine.BSF.3.96.980915062910.21829C-100000@bright.fx.genx.net> In-Reply-To: <199809150940.CAA00565@word.smith.net.au>
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On Tue, 15 Sep 1998, Mike Smith wrote: > I don't think anyone would disagree with this; my point was simply that > disks are effectively nondeterministic, so by definition you can't have > an "optimal" solution. > > I've seen assorted drive literature describing different caching > policies on modern drives, and I think it's probably in our interest > not to try too hard to outsmart the disk these days, as it's busy > trying to outsmart us. > > If you really wanted to play games with the queue sorter, you might > want to go for a minimal distance insertion policy rather than a strict > ladder sort. As Kirk pointed out, there's plenty of room for > experimentation in this field. 8) you can easily starve processes far from the insertion point using an algorithm like that, in fact you can almost DOS a machine unless some sort of quantum is invlolved to compromise locallity over time elapsed since a read/write has been queued. Alfred Perlstein - Programmer, HotJobs Inc. - www.hotjobs.com -- There are operating systems, and then there's FreeBSD. -- http://www.freebsd.org/ 3.0-current To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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