From owner-freebsd-arch Mon Jan 14 12: 9:15 2002 Delivered-To: freebsd-arch@freebsd.org Received: from root.com (root.com [209.102.106.178]) by hub.freebsd.org (Postfix) with ESMTP id E88F637B417; Mon, 14 Jan 2002 12:09:08 -0800 (PST) Received: (from dg@localhost) by root.com (8.11.2/8.11.2) id g0EJvdx09665; Mon, 14 Jan 2002 11:57:39 -0800 (PST) (envelope-from dg) Date: Mon, 14 Jan 2002 11:57:39 -0800 From: David Greenman To: Terry Lambert Cc: "James E. Housley" , Thomas Hurst , arch@FreeBSD.org Subject: Re: 64 bit counters again Message-ID: <20020114115739.E8955@nexus.root.com> References: <3C41F3FD.4ECC8CD@mindspring.com> <20020113231459.GA30349@voi.aagh.net> <3C42390A.F9E9F533@mindspring.com> <3C42E899.CB21BD0A@FreeBSD.org> <3C431EE5.1CFF557B@mindspring.com> <20020114100633.B8955@nexus.root.com> <3C43355D.8C9A35A0@mindspring.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3C43355D.8C9A35A0@mindspring.com>; from tlambert2@mindspring.com on Mon, Jan 14, 2002 at 11:45:33AM -0800 Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG >David Greenman wrote: >> >Actually, I was thinking that if what you are counting overflowed >> >in such a short period of time, then you are counting the wrong >> >thing. >> > >> >Instead of bytes, try counting K or frames, instead of frames, >> >count packets, etc.. >> >> Kbytes doesn't have enough resolution to provide accurate results since >> the packets themselves are not integer multiples of Kbytes. > >Use a modular counter; count bytes, and reflect them out at 1K >boundaries. Thus the accuracy is 1K, but the precision is 1 >byte. It's not how we "reflect them out" that's the problem. It's the overflow on the internal 32bit precision that's the problem. You could export the data in Kbps for all I care, but that has nothing to do with the problem. -DG David Greenman Co-founder, The FreeBSD Project - http://www.freebsd.org President, TeraSolutions, Inc. - http://www.terasolutions.com President, Download Technologies, Inc. - http://www.downloadtech.com Pave the road of life with opportunities. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message