From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: Workings/effectiveness of the xen-acpi-processor driver Date: Mon, 7 May 2012 13:33:06 -0400 Message-ID: <20120507173306.GC17704@phenom.dumpdata.com> References: <4F97F58A.8090409@canonical.com> <20120426155033.GE26830@phenom.dumpdata.com> <4F9976F8.8040502@canonical.com> <20120426170426.GI26830@phenom.dumpdata.com> <20120506152341.GX2058@reaktio.net> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: <20120506152341.GX2058@reaktio.net> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Pasi =?iso-8859-1?Q?K=E4rkk=E4inen?= Cc: "xen-devel@lists.xensource.com" , Stefan Bader , Jan Beulich List-Id: xen-devel@lists.xenproject.org On Sun, May 06, 2012 at 06:23:41PM +0300, Pasi K=E4rkk=E4inen wrote: > On Thu, Apr 26, 2012 at 01:04:26PM -0400, Konrad Rzeszutek Wilk wrote: > > > >> > > > >> This I would take as C3 and C6 really not being used and the frequ= ency scaling > > > > = > > > > To go in deeper modes there is also a need to backport a Xen unstab= le > > > > hypercall which will allow the kernel to detect the other states be= sides > > > > C0-C2. > > > > = > > > > "XEN_SET_PDC query was implemented in c/s 23783: > > > > "ACPI: add _PDC input override mechanism". > > > > = > > > = > > > I see. There is a kernel patch about enabling MWAIT that refers to th= at... > > = > > Yeah, I should see about back-porting it in Xen 4.1.. > > = > = > Should this patch be backported and merged to xen-4.1-testing.hg for Xen = 4.1.3 release ? = It is a new feature so no. Which does mean that the MWAIT states won't be u= ploaded to the hypervisor. But the legacy ones (so the ones that are in the ACPI _C= ST) are still uploaded. And TurboMode kicks in without the MWAIT states.