Subject: Re: kern/15232: ffs_sync writes out read-only pages to disk
To: Bill Sommerfeld <>
From: Bill Studenmund <>
List: tech-kern
Date: 01/14/2002 10:59:02
On Sun, 13 Jan 2002, Bill Sommerfeld wrote:

> > Surely there is a 'page modified' bit - and the write should only
> > happen if it is modified?
> this may just be updating the vnode 'last access' time.
> if you mount -o noatime,nodevmtime the disk should be more likely to
> spin down.

What would be nice is if we could pass info about the spun up/down state
further up the kernel, so we could create a class of operations which
happen when the disk is spun up, but not when it's spun down. That way we
could update atime when the disk is up, but not when it's down.

Take care,