Date: Tue, 2 Mar 2004 17:37:55 -0500 From: Garance A Drosihn <drosih@rpi.edu> To: Robert Watson <rwatson@freebsd.org>, Bruce Evans <bde@zeta.org.au> Cc: freebsd-current@freebsd.org Subject: Re: buildworld times Message-ID: <p060204aabc6abc525212@[128.113.24.47]> In-Reply-To: <Pine.NEB.3.96L.1040302170953.4906F-100000@fledge.watson.org> References: <Pine.NEB.3.96L.1040302170953.4906F-100000@fledge.watson.org>
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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@gilead.netel.rpi.edu Senior Systems Programmer or gad@freebsd.org Rensselaer Polytechnic Institute or drosih@rpi.edu
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