From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rusty Russell Subject: Re: [PATCH 1/2] lguest: handle dodgy/non-existent TSC. Host code. Date: Thu, 05 Jul 2007 11:38:45 +1000 Message-ID: <1183599525.6005.55.camel@localhost.localdomain> References: <1183529972.6005.1.camel@localhost.localdomain> <20070704132025.GZ11115@waste.org> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20070704132025.GZ11115@waste.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Matt Mackall Cc: Andrew Morton , virtualization List-Id: virtualization@lists.linuxfoundation.org On Wed, 2007-07-04 at 08:20 -0500, Matt Mackall wrote: > On Wed, Jul 04, 2007 at 04:19:32PM +1000, Rusty Russell wrote: > > Lguest currently requires a TSC, which breaks older machines and Matt > > Mackall who boots the host with "notsc". > > I do? I temporarily had a "notsc" arg in my lguest launcher script, > but removing it made no difference. I do* boot the host with NO_HZ though. NO_HZ should be OK, but last we spoke, "notsc" in the host caused lguest_data.tsc_khz to be zero => divide by zero errors (the previous fixes should sort out the other TSC issues). Anyway, if the host decides not to use the TSC, the guest shouldn't use it, which is the basis of this patch... Hope that clarifies, Rusty.