From owner-freebsd-current Mon Sep 14 15:30:42 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id PAA07094 for freebsd-current-outgoing; Mon, 14 Sep 1998 15:30:42 -0700 (PDT) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from merlin.camalott.com (merlin.camalott.com [208.229.74.19]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id PAA07023; Mon, 14 Sep 1998 15:30:12 -0700 (PDT) (envelope-from joelh@gnu.org) Received: from detlev.UUCP (tex-30.camalott.com [208.229.74.30]) by merlin.camalott.com (8.8.7/8.8.7) with ESMTP id RAA06240; Mon, 14 Sep 1998 17:30:54 -0500 Received: (from joelh@localhost) by detlev.UUCP (8.9.1/8.9.1) id RAA09230; Mon, 14 Sep 1998 17:29:30 -0500 (CDT) (envelope-from joelh) Date: Mon, 14 Sep 1998 17:29:30 -0500 (CDT) Message-Id: <199809142229.RAA09230@detlev.UUCP> To: Terry Lambert CC: joelh@gnu.org, tlambert@primenet.com, tom@uniserve.com, gpalmer@FreeBSD.ORG, irc@cooltime.simplenet.com, freebsd-current@FreeBSD.ORG In-reply-to: <199809141811.LAA18415@usr05.primenet.com> Subject: Re: Download of FreeBSD 3.0-SNAP From: Joel Ray Holveck Reply-to: joelh@gnu.org References: <199809141811.LAA18415@usr05.primenet.com> Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > 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. I would guess (and this is a guess, feel free to correct) that it's still fairly good, if it simply is performing an elevator sort keyed on block numbers. I would expect that most translations leave the order of the blocks alone. (ie, if block n is closer to the spindle than n+1, then both are closer than n+2, assuming a spiral instead of an actual CHS. Latency is still an issue, but not much.) This would mean that such a sort would still be 100% valid. Best, joelh -- Joel Ray Holveck - joelh@gnu.org - http://www.wp.com/piquan Fourth law of programming: Anything that can go wrong wi sendmail: segmentation violation - core dumped To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message