From owner-svn-src-all@FreeBSD.ORG Tue Jun 21 15:49:15 2011 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from [127.0.0.1] (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by hub.freebsd.org (Postfix) with ESMTP id E4FF8106564A; Tue, 21 Jun 2011 15:49:14 +0000 (UTC) (envelope-from jkim@FreeBSD.org) From: Jung-uk Kim To: John Baldwin Date: Tue, 21 Jun 2011 11:48:55 -0400 User-Agent: KMail/1.6.2 References: <201106081938.p58JcWuB044252@svn.freebsd.org> <201106201941.03393.jkim@FreeBSD.org> <201106210910.25697.jhb@freebsd.org> In-Reply-To: <201106210910.25697.jhb@freebsd.org> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201106211149.02280.jkim@FreeBSD.org> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org, Bruce Evans Subject: Re: svn commit: r222866 - head/sys/x86/x86 X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 21 Jun 2011 15:49:15 -0000 On Tuesday 21 June 2011 09:10 am, John Baldwin wrote: > On Monday, June 20, 2011 7:41:00 pm Jung-uk Kim wrote: > > My questions to you: > > > > a) Why do we care TSC timecounter when it is not invariant where > > we *know* it is unusable and set to negative quality? > > What if the user knows they will not enable CPU throttling so for > them the TSC is safe? In that case, TSC is a more efficient > timecounter and if the user constrains the system to make the TSC > safe we should let them use it. In that case, it must be a UP system, the quality is still 800, and TSC value won't be shifted. My question was specific to SMP cases. Sorry, I didn't make that clear. Jung-uk Kim