From owner-freebsd-hackers Thu Sep 2 11:17: 9 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from alpo.whistle.com (alpo.whistle.com [207.76.204.38]) by hub.freebsd.org (Postfix) with ESMTP id EAEF214D95; Thu, 2 Sep 1999 11:17:01 -0700 (PDT) (envelope-from julian@whistle.com) Received: from current1.whistle.com (current1.whistle.com [207.76.205.22]) by alpo.whistle.com (8.9.1a/8.9.1) with SMTP id LAA05003; Thu, 2 Sep 1999 11:15:35 -0700 (PDT) Date: Thu, 2 Sep 1999 11:16:34 -0700 (PDT) From: Julian Elischer To: nsayer@FreeBSD.ORG Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: CFD: "bogomips" CPU performance metric In-Reply-To: <37CEB68D.848BDAF8@sftw.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG There was such a thing in 386BSD and FreeBSD1.0 I certainly thing it was a worth-while thing. I'd try make the loop as similar to the Linux one so that they are comparable. On Thu, 2 Sep 1999, Nick Sayer wrote: > Linux generates a meric of CPU performance as a byproduct of calibrating > a delay loop. > We don't require doing any such thing, and so adding it would be purely > cosmetic. > However, I allege that cosmetic things aren't in and of themselves evil, > so long as > they don't break anything in the process. > > I would like to generate a number that will hopefully be reasonably > compatible with > the one Linux spits out. The best method I have come up with is to have > a similar > (the same?) count down loop in assembler. Have it count down from > 1,000,000 and > see how much nanotime() has gone by. NANSPERSEC/nansused = bogomips. > A 1 bogomips machine will take an extra second to do this (anything > likely to be > even able to run FreeBSD should exceed 1 BM - yes, ha ha), and a kBM CPU > > can do it in 1 ms. Perhaps in the future a prescaler might be required, > but > this whole thing is just really chrome anyway. > > Would anyone scream and projectile-vomit if I added this to identcpu.c? > > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message