Re: APM support for avoiding waking up laptops every few seconds?

Alan Cox (
Sun, 3 Aug 1997 21:57:07 +0100 (BST)

> 1 Just before the APM spins down the disk, a sync should be done.
> Though i'm not actually sure there's any way to request such notice.

APM doesn't spin the disk down in general. APM just set the disks own
spindown configuration at boot.

> 2 Whenever the disk is spun down sys_bdflush should be a noop
> The idea being that eventually a read will wake up the disk and all
> those dirty buffers will be flushed within five seconds. This will
> suck up a lot buffers but if the free list is empty refill_freelist
> will still work fine.

And if your machine crashes in that state you might lose hours of work.