From owner-svn-src-all@FreeBSD.ORG Wed Oct 22 18:35:51 2008 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 A7C641065671; Wed, 22 Oct 2008 18:35:50 +0000 (UTC) (envelope-from jkim@FreeBSD.org) From: Jung-uk Kim To: "Attilio Rao" Date: Wed, 22 Oct 2008 14:35:36 -0400 User-Agent: KMail/1.6.2 References: <200810210431.m9L4V7Pb088978@svn.freebsd.org> <3bbf2fe10810220853r34256b59y1fe57f49eca2014@mail.gmail.com> <200810221429.51834.jkim@FreeBSD.org> In-Reply-To: <200810221429.51834.jkim@FreeBSD.org> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200810221435.42202.jkim@FreeBSD.org> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r184108 - head/sys/i386/i386 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: Wed, 22 Oct 2008 18:35:51 -0000 On Wednesday 22 October 2008 02:29 pm, Jung-uk Kim wrote: > On Wednesday 22 October 2008 11:53 am, Attilio Rao wrote: > > 2008/10/21, Jung-uk Kim : > > > On Tuesday 21 October 2008 06:07 am, Attilio Rao wrote: > > > > Something we could do with this is adding a "quirk" table of > > > > TSC arch dependant known to be working (based on cpu_model > > > > and such) and use that table in order to replace tsc_smp. > > > > > > Please note the invariant_tsc and smp_tsc are different. If we > > > go with the route, we need two quirk tables. :-( > > > > It doesn't matter. > > I think it is silly we have different quirks flag states for TSC. > > We should just having a table assuming that the TSC is safe to > > use in SMP environments and gets rid of any other flag (in this > > case, for amd64 based machine, the logic could, for example, > > check if the CPU is P state invariant and assume it is safe, > > etc.) > > Yes, it does matter as TSC is not just for timecounter and it can > be used independently. For example, if a thread is bound to a CPU and the CPU has P-state invariant TSC, > it can provide the fastest AND safest timer. > Besides, the whole point was not to modify TSC freq. if it is > independent from CPU freq. > > Jung-uk Kim