From owner-freebsd-hackers Thu Sep 2 13:28:29 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from ns.mt.sri.com (ns.mt.sri.com [206.127.79.91]) by hub.freebsd.org (Postfix) with ESMTP id 5BD4514F55; Thu, 2 Sep 1999 13:28:20 -0700 (PDT) (envelope-from nate@mt.sri.com) Received: from mt.sri.com (rocky.mt.sri.com [206.127.76.100]) by ns.mt.sri.com (8.8.8/8.8.8) with SMTP id OAA01025; Thu, 2 Sep 1999 14:27:25 -0600 (MDT) (envelope-from nate@rocky.mt.sri.com) Received: by mt.sri.com (SMI-8.6/SMI-SVR4) id OAA28124; Thu, 2 Sep 1999 14:27:24 -0600 Date: Thu, 2 Sep 1999 14:27:24 -0600 Message-Id: <199909022027.OAA28124@mt.sri.com> From: Nate Williams MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: Julian Elischer Cc: nsayer@FreeBSD.ORG, freebsd-hackers@FreeBSD.ORG Subject: Re: CFD: "bogomips" CPU performance metric In-Reply-To: References: <37CEB68D.848BDAF8@sftw.com> X-Mailer: VM 6.34 under 19.16 "Lille" XEmacs Lucid Reply-To: nate@mt.sri.com (Nate Williams) Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > There was such a thing in 386BSD and FreeBSD1.0 I remember no such thing doing a 'bogomips' to compare against Linux. Certainly not in 386BSD. Nate > > 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 > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message