Date: Tue, 15 Sep 1998 11:44:56 +0100 (BST) From: Bob Bishop <rb@gid.co.uk> To: Terry Lambert <tlambert@primenet.com> Cc: dg@root.com, joelh@gnu.org, tom@uniserve.com, gpalmer@FreeBSD.ORG, irc@cooltime.simplenet.com, freebsd-current@FreeBSD.ORG Subject: Re: Download of FreeBSD 3.0-SNAP Message-ID: <Pine.BSF.3.96.980915113818.18739A-100000@seagoon> In-Reply-To: <199809150156.SAA12652@usr05.primenet.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Tue, 15 Sep 1998, Terry Lambert wrote: > > FreeBSD's disksort function sorts by block number, not by cylinder number. > > Hence it being non-optimal; see Mike's post... optimial is "always does > exactly the right thing". It's not pessimal, either (as Mike pointed > out, too). What's "exactly the right thing" though? If you have two I/O limited processes trying to access opposite ends of the disk, you probably max out the throughput by preferring the transfer closest to where the heads currently are. This will almost certainly result in the 'unlucky' process getting I/O starved, which may not be acceptable. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.BSF.3.96.980915113818.18739A-100000>