Date: Sun, 25 Jan 1998 23:32:55 +0000 (GMT) From: Terry Lambert <tlambert@primenet.com> To: mike@smith.net.au (Mike Smith) Cc: jbryant@unix.tfs.net, freebsd-current@FreeBSD.ORG Subject: Re: apm on toshiba Message-ID: <199801252332.QAA17175@usr02.primenet.com> In-Reply-To: <199801250858.TAA02250@word.smith.net.au> from "Mike Smith" at Jan 25, 98 07:28:18 pm
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> > i just got a toshiba laptop [portege 660cdt] from work, and am > > planning to run -current... > > > > has anything been done with the apm on these to support dim > > backlighting, and disk spindown? > > No. You can hotkey through your power settings, and organise your > disk spindown with the BIOS setup, but if you want to let the disk spin > down you need to stretch the update time out further. The update time only applies to dirty buffers. If you don't dirty any buffers, you won't spin up for update writes. If you do dirty buffers, you are probably doing reads to do it, so your disk will already be spun up. Either way, it should not be necessary to hack updated. One thing that *is* useful to do to updated is to force it, if it does an update on an FS and there is nothing to update since last time, to mark the FS clean and write out the superblock. A subsequent write access will need to take a hit for marking the FS dirty before allowing the write to go. This includes atime updates for reads, so it's most useful if atime is turned off. One should not include atime as an fs_time event, BTW. If you were paranoid, you could count number of times there was nothing to update, and go after a count, but I think that's overkill. There's really no overhead on a busy FS, since it will always have stuff to update. For an idle FS... well, it doesn't matter. 8-). This is a really useful thing, since it means that you can just turn idle systems off, and have a reasonable expectation of them coming up clean. Idle is defined as "not making many disk writes". Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.
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