Subject: Re: Recent pmap cleanup
To: , <>
From: Chris Gilbert <>
List: port-arm
Date: 03/24/2002 23:00:00
----- Original Message -----
From: "Jason R Thorpe" <>
To: <>
Sent: Sunday, March 24, 2002 9:37 PM
Subject: Recent pmap cleanup

> Folks...
> You may have noticed I've been cleaning up the pmap module over the
> last couple of days.  The net result of this should be a slight to
> moderate performance improvement, since a fairly expensive routine
> was deleted.  Chris Gilbert has promised to run his standard speed
> tests for me.

Standard test being:
cd pkgsrc/devel/gmake; make cleandir; make patch; time make configure
Note that pkgsrc is off an NFS mount, the workdir is on the local disk

Taking a reasonably old kernel (NetBSD 1.5ZA (GERRY) #41: Tue Jan 22
11:17:44 GMT 2002) time output was:
17.0u 38.6s 1:14.68 74.5% 0+0k 27+1550io 226pf+0w
using -current as of about now (NetBSD 1.5ZC (GERRY) #70: Sun Mar 24
22:17:15 GMT 2002) time output was:
16.9u 39.1s 1:14.21 75.5% 0+0k 26+1558io 231pf+0w

Perhaps it's time for me to find a new benchmark, this one doesn't show a
gain, but certainly not a lose 8)  Your mileage may vary.  I should really
get my risc-pc reconfigured and try the benchmarks on that.

> I've also taken a fairly expensive debug check out of the prefetch
> abort path of non-SA110 CPUs, and this may improve things, as well.
> I've tested all of this on a Shark with an SA110.  Please file a
> bug report with send-pr(1) if you have any trouble.

It also appears to work on cats 8)