Date: Mon, 14 Sep 1998 16:52:18 -0700 From: Mike Smith <mike@smith.net.au> To: Terry Lambert <tlambert@primenet.com> Cc: 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: <199809142352.QAA02068@dingo.cdrom.com> In-Reply-To: Your message of "Mon, 14 Sep 1998 18:11:38 -0000." <199809141811.LAA18415@usr05.primenet.com>
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> Note that David points out that FreeBSD *does* do elevator sorting; > it's still not optimal, however, since physical and logical cylinder > boundaries are infrequently the same on modern hardware. I have > to look before I say any more (since I thought the code was removed > circa 2.2.1). David says it's called on all "dumb" drivers (wd, etc.); > I'm not sure the "Ultra" DMA EIDE drivers are still in this category. You're talking about bufqdisksort(), which sorts a bp into a queue of bp's. Since it works with bp's, it's clear that it sorts on linear block offset, which isn't exactly optimal but is less suboptimal than pure randomness. -- \\ Sometimes you're ahead, \\ Mike Smith \\ sometimes you're behind. \\ mike@smith.net.au \\ The race is long, and in the \\ msmith@freebsd.org \\ end it's only with yourself. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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