Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!rutgers!mit-eddie!genrad!decvax!tektronix!teklds!midas!jacc From: jacc@midas.UUCP (Jac Colby) Newsgroups: comp.sys.amiga Subject: Re: Amiga Multi-tasking Overhead Message-ID: <926@midas.UUCP> Date: Sun, 14-Dec-86 16:41:01 EST Article-I.D.: midas.926 Posted: Sun Dec 14 16:41:01 1986 Date-Received: Tue, 16-Dec-86 18:40:25 EST References: <1986Dec2.102542.4658@utcs.uucp> <1085@cbmvax.cbmvax.cbm.UUCP> <1986Dec11.185731.13459@utcs.uucp> Reply-To: jacc@midas.TEK.COM (Jac Colby) Organization: Tektronix, Inc., Beaverton, OR. Lines: 26 In article <1986Dec11.185731.13459@utcs.uucp> wagner@utcs.UUCP (Michael Wagner) writes: >I'm getting more and more convinced that the problem is in the File systems >and the trackdisk.devices. I now have a copy of AMIGAMON20, and by turning >it up to very fast, I'm able to see that the trackdisk.devices and the file >systems are being dispatched regularly, even when there is no disk activity. When I was trying to figure out how to add my own external disks, I noticed that the select lines went active once every second if a disk was not present in a drive. When a disk is placed in a drive, its presence is always detected within one second, and the validator is run. However, the select lines *continue* to be pulsed, and at an even higher rate. I presume that this is done to check for disk removal. The disk-removed signal is active low, so detection of disk removal or insertion must be done by polling. An obvious question, though, is why doesn't the trackdisk.device just check for disk-removed prior to each disk access? I would guess that the overhead would go down if no disks are present when running benchmarks. Jac Colby - they disclaim me around here, too. UUCP: {ucbvax,decvax,pur-ee,cbosg,ihnss}!tektronix!midas!jacc -or- jacc@midas.TEK.COM US: 5529 SW Patton Rd, Portland, OR 97221 (503) 292-1609 -or- MS 94-442, PO Box 4600, Beaverton, OR, 97075 (503) 629-1129