From owner-freebsd-stable@FreeBSD.ORG Tue Feb 22 19:57:45 2005 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id C72DA16A4CE for ; Tue, 22 Feb 2005 19:57:45 +0000 (GMT) Received: from cyrus.watson.org (cyrus.watson.org [204.156.12.53]) by mx1.FreeBSD.org (Postfix) with ESMTP id 175E943D3F for ; Tue, 22 Feb 2005 19:57:43 +0000 (GMT) (envelope-from robert@fledge.watson.org) Received: from fledge.watson.org (fledge.watson.org [204.156.12.50]) by cyrus.watson.org (Postfix) with SMTP id BFB4046B91; Tue, 22 Feb 2005 14:57:42 -0500 (EST) Date: Tue, 22 Feb 2005 19:56:03 +0000 (GMT) From: Robert Watson X-Sender: robert@fledge.watson.org To: Kevin Oberman In-Reply-To: <20050222193858.1C18C5D07@ptavv.es.net> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII cc: Emanuel Strobl cc: freebsd-stable@freebsd.org Subject: Re: HZ in RELENG_5? tcp_subr.c related X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Feb 2005 19:57:45 -0000 On Tue, 22 Feb 2005, Kevin Oberman wrote: > > In RELENG_5, the default HZ for amd64 is 1000, but for all other platforms > > it is 100. So amd64 users will see a ten-fold decrease in tcp_isn_tick() > > running, but i386 (and other) users will see no change. > > Now that 5 is STABLE, I guess we are stuck with it, but in an era of > "slow" 2GHz systems, it seems like a questionable choice. I know that > there are a lot of folks running old hardware (like my trusty old K6), > but they are a minority and changing HZ is not a big deal. Why make the > majority live with 100 on fast systems or know enough to manually change > it? > > Has there been discussion of changing this for V6 or is there a reason I > missed for keeping HZ at 100 in the iX86 platforms. In 6-CURRENT, HZ is 1000 for amd64, i386, and ia64, but 100 for other platforms (i.e., ppc, arm, and alpha). I'm not opposed to merging the HZ change to RELENG_5 at some point, but given that occasional nits, such as the TCP nit, are turning up, I think it's worth waiting until after 5.4. Robert N M Watson