Date: Fri, 12 May 2000 00:32:16 -0700 From: Kent Stewart <kstewart@3-cities.com> To: Kris Kennaway <kris@FreeBSD.org> Cc: George Cox <gjvc@sophos.com>, freebsd-hackers@freebsd.org Subject: Re: Double buffered cp(1) Message-ID: <391BB380.2A9E07C6@3-cities.com> References: <Pine.BSF.4.21.0005112219060.49885-100000@freefall.freebsd.org>
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Kris Kennaway wrote: > > On Mon, 24 Apr 2000, Kent Stewart wrote: > > > This is what I see on a buildworld with 4.0-Stable > > > > Modified /etc/make.conf and commented out CFLAGS= -Os -pipe > > 3707.4u 799.6s 1:35:52.46 78.3% 1374+1477k 56974+173232io 2337pf+0w > > 3693.9u 800.5s 1:29:45.73 83.4% 1375+1477k 55201+173224io 2160pf+0w > > Modified /etc/make.conf and added CFLAGS= -pipe > > 3559.2u 807.2s 1:28:00.05 82.6% 1608+1286k 56499+174033io 2516pf+0w > > This is an old message, but what you're seeing here is that if CFLAGS is > not overridden, it is set by sys.mk to "-O -pipe" > > Setting CFLAGS explicitly to "-pipe" is faster because it does no > optimization, "-Os -pipe" would be slower because it does more. Leaving > out -pipe would be slower still, because the compiler does data passing > using temporary files in /tmp instead of via a pipe. Part of this you had to go back about 15-20 messages. There were some comments about options that would speed the system up. I then ran both styles of buildworlds on kernels built with the -Os to see if my buildworld times changed. It wasn't significant. A long about this same time I ran some tests with using this for IBM DCAS drive current setup. da0: <IBM DCAS-34330W S65A> Fixed Direct Access SCSI-2 device da0: 40.000MB/s transfers (20.000MHz, offset 8, 16bit), Tagged Queueing Enabled da0: 4134MB (8467200 512 byte sectors: 255H 63S/T 527C) Previously, the tagged queueing was turned off. I have run a number of tests with 4.0-Stable and enabling tagged queueing on this drive didn't slow the disk down. It really didn't speed it up to speak of either. Kent > > Kris > > ---- > In God we Trust -- all others must submit an X.509 certificate. > -- Charles Forsythe <forsythe@alum.mit.edu> > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-hackers" in the body of the message -- Kent Stewart Richland, WA mailto:kstewart@3-cities.com http://www.3-cities.com/~kstewart/index.html FreeBSD News http://daily.daemonnews.org/ SETI(Search for Extraterrestrial Intelligence) @ HOME http://setiathome.ssl.berkeley.edu/ Hunting Archibald Stewart, b 1802 in Ballymena, Antrim Co., NIR http://www.3-cities.com/~kstewart/genealogy/archibald_stewart.html To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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