53 messages in org.freebsd.freebsd-currentRe: Download of FreeBSD 3.0-SNAP | From | Sent On | Attachments |
|---|---|---|
| Daniel Hawton | Sep 12, 1998 10:59 pm | |
| Tom | Sep 13, 1998 12:17 am | |
| Gary Palmer | Sep 13, 1998 1:16 am | |
| Joel Ray Holveck | Sep 13, 1998 8:14 am | |
| Tom | Sep 13, 1998 10:16 am | |
| Chuck Robey | Sep 13, 1998 10:18 am | |
| Stefan Eggers | Sep 13, 1998 11:26 am | |
| Gary Palmer | Sep 13, 1998 12:57 pm | |
| Terry Lambert | Sep 13, 1998 4:43 pm | |
| David Greenman | Sep 13, 1998 9:11 pm | |
| Dan Strick | Sep 14, 1998 2:16 am | |
| David Greenman | Sep 14, 1998 10:21 am | |
| Joel Ray Holveck | Sep 14, 1998 10:38 am | |
| Terry Lambert | Sep 14, 1998 11:07 am | |
| Terry Lambert | Sep 14, 1998 11:11 am | |
| Terry Lambert | Sep 14, 1998 2:55 pm | |
| Joel Ray Holveck | Sep 14, 1998 3:29 pm | |
| Mike Smith | Sep 14, 1998 4:51 pm | |
| David Greenman | Sep 14, 1998 5:22 pm | |
| David O'Brien | Sep 14, 1998 6:19 pm | |
| Terry Lambert | Sep 14, 1998 6:55 pm | |
| David Greenman | Sep 14, 1998 7:22 pm | |
| Poul-Henning Kamp | Sep 14, 1998 11:43 pm | |
| Mike Smith | Sep 15, 1998 2:39 am | |
| Mike Smith | Sep 15, 1998 3:43 am | |
| Bob Bishop | Sep 15, 1998 3:44 am | |
| Alfred Perlstein | Sep 15, 1998 4:31 am | |
| Matthew N. Dodd | Sep 15, 1998 7:49 am | |
| Terry Lambert | Sep 15, 1998 1:01 pm | |
| Terry Lambert | Sep 15, 1998 1:05 pm | |
| Terry Lambert | Sep 15, 1998 1:10 pm | |
| Joel Ray Holveck | Sep 15, 1998 1:52 pm | |
| Gary Palmer | Sep 15, 1998 2:49 pm | |
| Mike Smith | Sep 15, 1998 3:58 pm | |
| Lee Cremeans | Sep 15, 1998 4:37 pm | |
| Poul-Henning Kamp | Sep 16, 1998 12:04 am | |
| Mike Smith | Sep 16, 1998 12:23 am | |
| Poul-Henning Kamp | Sep 16, 1998 12:25 am | |
| Terry Lambert | Sep 16, 1998 1:54 pm | |
| Terry Lambert | Sep 16, 1998 2:53 pm | |
| Mike Smith | Sep 16, 1998 2:55 pm | |
| Mike Smith | Sep 16, 1998 3:10 pm | |
| Terry Lambert | Sep 16, 1998 4:04 pm | |
| Terry Lambert | Sep 16, 1998 4:05 pm | |
| Mike Smith | Sep 16, 1998 4:25 pm | |
| Stephen Hocking-Senior Programmer PGS Tensor Perth | Sep 16, 1998 7:32 pm | |
| Bob Bishop | Sep 17, 1998 1:57 am | |
| Dan Strick | Sep 17, 1998 2:05 am | |
| Mike Smith | Sep 17, 1998 9:18 am | |
| Terry Lambert | Sep 17, 1998 5:46 pm | |
| Mike Smith | Sep 17, 1998 6:13 pm | |
| Terry Lambert | Sep 17, 1998 7:03 pm | |
| Joel Ray Holveck | Sep 17, 1998 7:38 pm |
| Subject: | Re: Download of FreeBSD 3.0-SNAP | |
|---|---|---|
| From: | Poul-Henning Kamp (ph...@critter.freebsd.dk) | |
| Date: | Sep 14, 1998 11:43:32 pm | |
| List: | org.freebsd.freebsd-current | |
In message <1998...@detlev.UUCP>, Joel Ray Holveck writes:
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.
Well, this is almost still the case. Most modern disks lay out the sectors in a track backwards, they start reading as soon as they hit the track and cache all they get. That means that if you ask for sector 5, there is a good likelyhood that 6, 7, 8... is already in the cache when you ask for them a moment later.
-- Poul-Henning Kamp FreeBSD coreteam member ph...@FreeBSD.ORG "Real hackers run -current on their laptop." "ttyv0" -- What UNIX calls a $20K state-of-the-art, 3D, hi-res color terminal
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