Re: Cached file read performance

Quoting Bruce Evans <bde@xxxxxxxxxxx> (Fri, 22 Dec 2006 23:37:53 +1100 (EST)):

On Fri, 22 Dec 2006, Adrian Chadd wrote:

On 22/12/06, David Xu <davidxu@xxxxxxxxxxx> wrote:

I suspect in such a test, memory copying speed will be a key factor,
I don't have number to back up my idea, but I think Linux has lots
of tweaks, such as using MMX instruction to copy data.

I had the oppertunity to study the AMD Athlon XP Optimisation guide
and noted their example copy routine, optimised for the chipset, was
quite a hell of a lot faster over a straight block copy.

Has anyone here done any similar modifications to optimise
copyin/copyout? I can't imagine it'd be a bad thing to have.

Sure. It's a larger win mainly in benchmarks. It's a twisty MD maze.

I want to point out http://www.freebsd.org/projects/ideas/#p-memcpy
here. Just in case someone wants to play around a little bit.

Bye,
Alexander.

--
I like your SNOOPY POSTER!!
http://www.Leidinger.net Alexander @ Leidinger.net: PGP ID = B0063FE7
http://www.FreeBSD.org netchild @ FreeBSD.org : PGP ID = 72077137
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