From owner-freebsd-current@FreeBSD.ORG Wed Jan 2 18:40:55 2008 Return-Path: Delivered-To: current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 7180B16A481 for ; Wed, 2 Jan 2008 18:40:55 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from cyrus.watson.org (cyrus.watson.org [209.31.154.42]) by mx1.freebsd.org (Postfix) with ESMTP id 447A113C458 for ; Wed, 2 Jan 2008 18:40:55 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from fledge.watson.org (fledge.watson.org [209.31.154.41]) by cyrus.watson.org (Postfix) with ESMTP id C842149605; Wed, 2 Jan 2008 13:40:54 -0500 (EST) Date: Wed, 2 Jan 2008 18:40:54 +0000 (GMT) From: Robert Watson X-X-Sender: robert@fledge.watson.org To: Ed Maste In-Reply-To: <20080102182732.N30578@fledge.watson.org> Message-ID: <20080102183522.T30578@fledge.watson.org> References: <20071228015651.X1565@odysseus.silby.com> <20071228095539.F45653@fledge.watson.org> <20071229180004.O6052@odysseus.silby.com> <477A627A.8010601@FreeBSD.org> <20080101222654.A8764@odysseus.silby.com> <20080102160322.GA83957@sandvine.com> <20080102182732.N30578@fledge.watson.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: Mike Silbersack , "Bruce M. Simpson" , current@freebsd.org Subject: Re: [patch] Auto-setting hz to 100 inside QEMU/VMWare X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 02 Jan 2008 18:40:55 -0000 On Wed, 2 Jan 2008, Robert Watson wrote: >> I've only tried it out with qemu so far. I'd appreciate reports of any >> testing with other emulators, and comments from loader/forth gurus. > > With this patch, is one forced to use a HZ of 100 when running under a VM > unless one modifies the loader scripts? There are times when I experiment > with alternative HZ settings in VMs, and as such it would be nice to have an > intentional way to turn off auto-setting of HZ, and/oor specify what the VM > HZ should be, using loader.conf. On a similar note, it would be nice if there were a kenv/sysctl hw.virtualized that was derived from the loader's decision (or in some other way), which could then be used to key other configuration choices than HZ. For example, in the future we might want to change the way we did idle loops, power management, process acounting, etc. This could be used to key a HZ selection in kernel rather than hard-coding knowledge of HZ into the loader environment. Robert N M Watson Computer Laboratory University of Cambridge