buildworld times

[Garance A Drosihn]

At 5:18 PM -0500 3/2/04, Robert Watson wrote:
>On Wed, 3 Mar 2004, Bruce Evans wrote:
>  >
>>  > (2) If we reran these tests with 5.2-CURRENT, how would the numbers
>>  >     change?
>>
>>  I would be surprised if they changed much.  buildworld is mostly a gcc
>>  cpu hog benchmark, and about the only significant thing the kernel can
>>  do to speed up gcc is to reduce its memory contention.
>
>Interestingly, on the same hardware using 5.2-CURRENT GENERIC - WITNESS,
>INVARIANTS, et al (with ULE since that's the default now):
>
>                 Real            User            Sys
>default		2304.16		1834.51		474.96         # slower
>-j 2		1611.61		2715.89		684.97         # faster!
>-j 4		1416.11		2988.32		878.40         # faster!
>-j 6		1399.92		3090.95		955.74         # fastest!
>-j 8		1405.38		3151.92		1003.69        # fasterish!
>
>Note that this was a 5.2.1 source tree built on a 5.2-current system, so
>isn't a perfect comparison.  I should have used a 5.2.1-current world
>changing out only the kernel.

When did the change to make go in?  That would probably result in
a difference in speed, especially for -j builds.  The change to add
a SIGCHLD handler...

Bah, I can look it up as much as anyone else can.  From
http://www.freebsd.org/cgi/cvsweb.cgi/src/usr.bin/make/main.c

it looks like that change went in right after 5.2-release.  So
that is probably a part of what you're seeing.

-- 
Garance Alistair Drosehn            =   gad at gilead.netel.rpi.edu
Senior Systems Programmer           or  gad at freebsd.org
Rensselaer Polytechnic Institute    or  drosih at rpi.edu