Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!rutgers!sri-unix!hplabs!decwrl!sun!imagen!atari!dyer From: dyer@atari.UUcp (Landon Dyer) Newsgroups: comp.sys.atari.st Subject: Re: Expanding the GEMDOS buffer list - is it a good idea?? Message-ID: <511@atari.UUcp> Date: Sun, 11-Jan-87 11:53:40 EST Article-I.D.: atari.511 Posted: Sun Jan 11 11:53:40 1987 Date-Received: Mon, 12-Jan-87 03:44:36 EST References: <2135@felix.UUCP> Organization: Atari Corp., Sunnyvale CA Lines: 37 in article <2135@felix.UUCP>, preston@felix.UUCP (Preston L. Bannister) says: > > I wouldn't mind allocating a hundred buffers (or so) if it would reduce > the number of disk accesses. File access is a _lot_ slower than it > should be on my hard disk, due to the large number of disk accesses for > even simple operations. MS_DOS lets you do something similar by > putting a line like 'BUFFERS=100' to allocate 100 buffers for caching > disk sectors. > > Is this a good idea with GEMDOS? Is it safe? Will it work? (Anyone > at Atari or DRI listening?) > > I'd be willing try the experiment, but it would be nice if someone > would take a look at the actual GEMDOS code to make sure it isn't a > waste of time. Adding buffers will increase performance --- but adding 100 of them on GEMDOS's buffer lists is probably a bad idea; GEMDOS does a linear search on the list. It also likes to invalidate perfectly good blocks, so even if you add 10, there's no g'tee they'll all get used. Adding blocks is probably best done at the Rwabs() level, with a good disk block cache. Should be easy. Unfortunately, GEMDOS is slow because it has problems at the "genetic" level, which can't be fixed with patches or small modifications. We *are* working on a new file system, it will be significantly faster, and it's going to be a while yet.... -- -Landon Dyer, Atari Corp. {sun,lll-lcc,imagen}!atari!dyer /-----------------------------------------------\ | The views represented here do not necessarily | "If Business is War, then | reflect those of Atari Corp., or even my own. | I'm a Prisoner of Business!" \-----------------------------------------------/