From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boris Ostrovsky Subject: Re: [PATCH] Intel/vpmu: Use Intel VPMU quirk on all family 6 processors Date: Thu, 30 May 2013 12:44:59 -0400 Message-ID: <51A7820B.2070408@oracle.com> References: <1368131669-1629-1-git-send-email-boris.ostrovsky@oracle.com> <518C0B05.6040403@oracle.com> <5194ED6F02000078000D6B7C@nat28.tlf.novell.com> <51A77F5B.3090508@oracle.com> <51A78074.9020608@eu.citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <51A78074.9020608@eu.citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: George Dunlap Cc: "xen-devel@lists.xensource.com" , Jan Beulich , Konrad Rzeszutek Wilk , Eddie Dong , Donald D Dugger , Dietmar Hahn , Jun Nakajima , Haitao Shan List-Id: xen-devel@lists.xenproject.org On 05/30/2013 12:38 PM, George Dunlap wrote: > On 05/30/2013 05:33 PM, Boris Ostrovsky wrote: >> On 05/16/2013 08:30 AM, Jan Beulich wrote: >>>>>> On 10.05.13 at 11:46, George Dunlap >>>>>> wrote: >>>> On Thu, May 9, 2013 at 9:45 PM, Boris Ostrovsky >>>> wrote: >>>>> On 05/09/2013 04:34 PM, Boris Ostrovsky wrote: >>>>>> Currently only a few Intel models have VPMU workaround turned on. It >>>>>> appears, however, that this issue exists on more models than what is >>>>>> covered by check_pmc_quirk(). Since we don't know exactly which cpus >>>>>> are affected we should turn this workaround on for all family 6 >>>>>> processors. >>>>> >>>>> Haitao, >>>>> >>>>> A few weeks ago we had an email thread about this issue >>>>> (http://lists.xen.org/archives/html/xen-devel/2013-03/msg02618.html) >>>>> Did you have a chance to clarify with your HW folks what this is? >>>>> >>>>> We kept hitting this on various models which is why I am suggesting >>>>> this >>>>> patch (and I think it should be considered for 4.3). >>>> In principle it's a bug fix, and fine for 4.3. But it would be good >>>> to get some feedback from someone at Intel. >>> Intel, anyone??? >>> >>> Thanks, Jan >>> >> >> I haven't seen any responses from Intel folks about this issue. >> >> Do we wait for post-4.3? > > Our goals at this point: > - Bug-free release > - Awesome release > - On-time release > > I take it that the main risk here is that vcpu for some models which > would have otherwise worked will not work anymore? (I assume you meant vpmu, not vcpu). Yes, that would be the main risk. -boris > > But at his point you *know* many models which don't work without it; > so on the whole I'm inclined to say that it's an "accept" on the > cost/benefits analysis. > > -George