From mboxrd@z Thu Jan 1 00:00:00 1970 From: George Dunlap Subject: Re: [PATCH] Intel/vpmu: Use Intel VPMU quirk on all family 6 processors Date: Thu, 30 May 2013 17:38:12 +0100 Message-ID: <51A78074.9020608@eu.citrix.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> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <51A77F5B.3090508@oracle.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: Boris Ostrovsky 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 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? 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