From owner-freebsd-hackers Mon May 4 00:42:44 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id AAA09347 for freebsd-hackers-outgoing; Mon, 4 May 1998 00:42:44 -0700 (PDT) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from freebie.lemis.com (freebie.lemis.com [139.130.136.133]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id AAA09342 for ; Mon, 4 May 1998 00:42:36 -0700 (PDT) (envelope-from grog@lemis.com) Received: (from grog@localhost) by freebie.lemis.com (8.8.8/8.8.7) id RAA06760; Mon, 4 May 1998 17:10:54 +0930 (CST) (envelope-from grog) Message-ID: <19980504171054.X4777@freebie.lemis.com> Date: Mon, 4 May 1998 17:10:54 +0930 From: Greg Lehey To: Joerg Micheel Cc: John-Mark Gurney , FreeBSD Hackers Subject: Re: Context switch time References: <19980425034313.55993@hydrogen.nike.efn.org> <19980504143736.L4777@freebie.lemis.com> <19980503222303.36966@hydrogen.nike.efn.org> <19980504140442.52763@krdl.org.sg> <19980504155242.P4777@freebie.lemis.com> <19980504152056.47011@krdl.org.sg> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.91.1i In-Reply-To: <19980504152056.47011@krdl.org.sg>; from Joerg Micheel on Mon, May 04, 1998 at 03:20:56PM +0800 WWW-Home-Page: http://www.lemis.com/~grog Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-41-739-7062 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Mon, 4 May 1998 at 15:20:56 +0800, Joerg Micheel wrote: > Greg, > > maybe, we should exchange our test programs :-). #include #include main (int argc, char *argv []) { int i; int count = 1; if (argc > 1) count = atoi (argv [1]); for (i = 0; i < count; i++) getuid (); } Hmm, interesting, it's called getpid.c, but it calls getuid :-) > On Mon, May 04, 1998 at 03:52:42PM +0930, Greg Lehey wrote: >> On Mon, 4 May 1998 at 14:04:42 +0800, Joerg Micheel wrote: >>> On Sun, May 03, 1998 at 10:23:03PM -0700, John-Mark Gurney wrote: >>>> Greg Lehey scribbled this message on May 4: >>>>> On Sat, 25 April 1998 at 3:43:13 -0700, John-Mark Gurney wrote: >>>>> >>>>> Strange. This is what I get from a program that repeatedly calls >>>>> getpid() on my K6/233: >>> >>> These numbers might not that much depend on processor type/speed. What >>> about memory/cache speed ? Chipset ? Comments ? >> >> I think they have quite a strong relationship with processor power. > >> In particular, the P5/133 and your P5/200 seem to handle about 3500 >> syscalls/MHz. The P5/75 is presumably slower because of the missing >> cache, and I've noticed before that the K6 isn't as much faster at >> this sort of thing as I would expect--suggestions for the reasons are >> welcome. One could be that it's an Inten TX board with 96 MB, of >> which only 64 MB are cached, but it seems to match up with John-Mark's >> observations. > > Here is the Dell OptiPlex GXa, a 300 MHz PentiumPro: > > (results omitted) > 1375755 usecs/1000000 calls, 726873 calls/sec > > You seem to be right in some way, but the result does not directly suggest that > there is a 1:1 relationship with processor speed, at least not on the high-end machines. > The performance gain on the 300 MHz machine is VERY slight (around 1%). > > Unfortunately, I currently don't have any slower machines around. I might > try on my 133MHz Pentium at home tonight. Hmmm. This suggests to me that we're hitting some other limit. Greg -- See complete headers for address and phone numbers finger grog@lemis.com for PGP public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message