From owner-freebsd-hackers@FreeBSD.ORG Mon Jan 28 18:59:50 2008 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B752716A417 for ; Mon, 28 Jan 2008 18:59:50 +0000 (UTC) (envelope-from sam@errno.com) Received: from ebb.errno.com (ebb.errno.com [69.12.149.25]) by mx1.freebsd.org (Postfix) with ESMTP id 8EC5813C448 for ; Mon, 28 Jan 2008 18:59:50 +0000 (UTC) (envelope-from sam@errno.com) Received: from trouble.errno.com (trouble.errno.com [10.0.0.248]) (authenticated bits=0) by ebb.errno.com (8.13.6/8.12.6) with ESMTP id m0SIxosB061691 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Mon, 28 Jan 2008 10:59:50 -0800 (PST) (envelope-from sam@errno.com) Message-ID: <479E2626.6040207@errno.com> Date: Mon, 28 Jan 2008 10:59:50 -0800 From: Sam Leffler User-Agent: Thunderbird 2.0.0.9 (X11/20071125) MIME-Version: 1.0 To: Sean Bruno References: <479E0A1C.2060908@miralink.com> <20080128134253.C1539@mail.tacorp.net> <479E24A1.60103@miralink.com> In-Reply-To: <479E24A1.60103@miralink.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-DCC--Metrics: ebb.errno.com; whitelist Cc: freebsd-hackers@freebsd.org Subject: Re: How long is a hz? X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 28 Jan 2008 18:59:50 -0000 Sean Bruno wrote: > Jason Slagle wrote: >> On Mon, 28 Jan 2008, Sean Bruno wrote: >> >>> I couldn't quite find the definition for "hz" in sys/ this morning. >>> What is it's value and where is it defined? >> >> From http://en.wikipedia.org/wiki/Hertz >> >> The hertz (symbol: Hz) is the International System of Units (SI) base >> unit of frequency. Its base unit is cycle/s or s^-1 (also called >> inverse seconds, reciprocal seconds). In English, hertz is used as >> both >> singular and plural. As any SI unit, Hz can be prefixed; commonly >> used >> multiples are kHz (kilohertz, 10^3 Hz), MHz (megahertz, 10^6 Hz), GHz >> (gigahertz, 10^9 Hz) and THz (terahertz, 10^12 Hz). >> >> One hertz simply means one cycle per second (typically that which is >> being counted is a complete cycle); 100 Hz means one hundred >> cycles per >> second, and so on. The unit may be applied to any periodic event--for >> example, a clock might be said to tick at 1 Hz, or a human heart >> might >> be said to beat at 1.2 Hz. The frequencies of aperiodic events, >> such as >> radioactive decay, are expressed in becquerels. >> >> > But more importantly, where is "hz" defined in the kernel tree? > > Sean > _______________________________________________ > freebsd-hackers@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hackers > To unsubscribe, send any mail to > "freebsd-hackers-unsubscribe@freebsd.org" > > http://fxr.watson.org/fxr/ident?i=hz