Subject: Re: pmap tweak sanity check
To: Chris Gilbert <email@example.com>
From: Jason R Thorpe <firstname.lastname@example.org>
Date: 11/12/2002 10:58:37
On Tue, Nov 12, 2002 at 04:15:25PM -0000, Chris Gilbert wrote:
> An optimisation I've just thought of, is it worth adding flags to the
> pvh_attrs field of the vm_page_md stuff that indicates that all entries in
> this vm_page list are readonly and therefore all cacheable? that way when
> we add a new readonly pv to the list we don't have to walk the list, we
> just add it in.
I'd use counters -- a flag might require a traversal of the list again
to update the flag. A counter would not.
as the counters? This way you only need to incr/decr the counters, and
check them for != 0. Counters should be unsigned, and sprinkle some
KDASSERT()s in there to detect underflow.
-- Jason R. Thorpe <email@example.com>