Date: Sat, 05 Apr 2003 19:06:23 GMT From: Tor.Egge@cvsup.no.freebsd.org To: des@ofug.org Cc: cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/conf options.i386 src/sys/i386/i386 tsc.c src/sys/i386/conf NOTES Message-ID: <20030405190623H.tegge@cvsup.no.freebsd.org> In-Reply-To: <xzp7ka9cgp3.fsf@flood.ping.uio.no> References: <200304042354.h34NslFp075997@repoman.freebsd.org> <xzp7ka9cgp3.fsf@flood.ping.uio.no>
next in thread | previous in thread | raw e-mail | index | archive | help
> Tor Egge <tegge@FreeBSD.org> writes: > > Log: > > Add SMP_TSC option, which can be used on SMP systems where the TSCs > > are synchronized to reduce context switch cost. > > Out of curiosity, what kind of systems would that be? Dell PowerEdge 2450, 2 x 733 MHz PIII CPUs, 1 GB memory. Elapsed times of "dd if=/dev/da0s4g of=/dev/null bs=512 count=200000" test: 5.0-CURRENT 5.0-CURRENT 5.0-CURRENT 4.8-RELEASE 4.8-RELEASE i8254 ACPI-safe TSC i8254 TSC 48.010578 35.460545 29.709355 13.326655 12.426712 48.041532 35.153883 29.797299 13.359450 12.411480 48.039143 35.113667 29.610601 13.349306 12.804534 47.630433 35.163372 30.036985 13.258281 12.473128 47.693183 35.240809 29.728361 13.332692 12.473128 Which gives average microseconds/read of 239 176 149 67 63 - Tor Egge
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20030405190623H.tegge>