Subject: Re: mmap(2) performance netbsd-1-6 vs. -current
To: Bang Jun-Young <junyoung@netbsd.org>
From: Jason Thorpe <thorpej@wasabisystems.com>
List: tech-kern
Date: 10/19/2003 13:19:27
On Sunday, October 19, 2003, at 01:06 PM, Bang Jun-Young wrote:
> This time numbers varied slightly, so I took the median values of 10
> trials. Here, -current was only marginally faster than netbsd-1-6,
> and it's obvious that it had nothing to do with improvements made in
> UVM in -current. This result makes me wonder why the previous silly
> test showed such a noticable difference.
I think what it tells us is:
- If you only count the mapping of the region, -current is
faster. This is probably due to Andrew Brown's map entry
merging changes.
- Servicing the page fault later is not faster in -current
than it was in 1.6.
(In your first test, you were still performing the mapping operations,
you just weren't faulting in any pages except the first one.)
-- Jason R. Thorpe <thorpej@wasabisystems.com>