Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 24 Oct 2003 14:11:53 -0700 (PDT)
From:      Ted Unangst <tedu@stanford.edu>
To:        Michel TALON <talon@lpthe.jussieu.fr>
Cc:        freebsd-hackers@freebsd.org
Subject:   Re: Some mmap observations compared to Linux 2.6/OpenBSD
Message-ID:  <Pine.GSO.4.44.0310241406390.6538-100000@saga0.Stanford.EDU>
In-Reply-To: <20031024112740.GA20599@lpthe.jussieu.fr>

next in thread | previous in thread | raw e-mail | index | archive | help
On Fri, 24 Oct 2003, Michel TALON wrote:

> What is more interesting is to look at the actual benchmark results in
> http://bulk.fefe.de/scalability/
> in particular the section about mmap benchmarks, the only one where
> OpenBSD shines. However as soon as touching pages is benchmarked
> OpenBSD fails very much.

look closer.  openbsd's "touch page" times are identical to what you'd
expect a disk access to be.  the pages aren't cached, they're read from
disk.  so compared to systems that don't read from disk, it looks pretty
bad.  a 5 line patch to fix the benchmark so that the file actually is
cached on openbsd results in performance much in line with freebsd/linux.


-- 
"People have criticized me because my security detail is larger
than the president's.  But you must ask yourself: are there more
people who want to kill me than who want to kill the president?
I can assure you there are."
      - M. Barry, Mayor of Washington, DC



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.GSO.4.44.0310241406390.6538-100000>