Subject: Re: Faster pipes, now with uvm_loan()
To: Jaromr <jdolecek@netbsd.org>
From: Chris Gilbert <chris@paradox.demon.co.uk>
List: tech-kern
Date: 04/10/2001 21:04:26
On Monday 09 April 2001  8:08 pm, "Jaromr" Dolecek wrote:
> Hi,
> thanks to Chuck Cranor's help, patch to uvm_loan() and point towards
> right direction, I got the version using uvm_loan() working. uvm_loan() is
> used for "big enough" transfers. Performance improvement for
> lmbench/bw_pipe on my PIII/600 was about 20%, on my 386DX ~30%:
>
>          old pipes        new pipes         new pipes with uvm_loan()
> PIII     487    MB/sec    487    MB/sec     567    MB/sec
> 386DX      0.75 MB/sec      3.57 MB/sec       4.70 MB/sec

Just for comparison, RiscPC StrongArm kinetic card:
	     1.78 MB/sec     xxx		7.82 MB/sec

Which is a good gain (note that a RiscPC has a 16MHz memory bus, so I'd 
expect low figures)

Cheers,
Chris