From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boris Ostrovsky Subject: Re: Problems with merlot* AMD Opteron 6376 systems (Was Re: stable trees Date: Mon, 29 Jun 2015 09:13:44 -0400 Message-ID: <55914488.4090500@oracle.com> References: <558151930200007800085E5C@mail.emea.novell.com> <21889.19282.1828.571256@mariner.uk.xensource.com> <5582C989020000780008696A@mail.emea.novell.com> <1434637353.28264.37.camel@citrix.com> <5584024B0200007800086F10@mail.emea.novell.com> <1434712049.28264.100.camel@citrix.com> <1435136770.28264.252.camel@citrix.com> <1435138723.28264.279.camel@citrix.com> <1435315055.32500.161.camel@citrix.com> <558D5F96020000780008A461@mail.emea.novell.com> <1435329265.32500.194.camel@citrix.com> <558D8369020000780008A5E4@mail.emea.novell.com> <558DA9AB.5060808@oracle.com> <1435349279.17598.66.camel@citrix.com> <1435573421.32500.250.camel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1Z9Ysz-0007fV-E8 for xen-devel@lists.xenproject.org; Mon, 29 Jun 2015 13:14:09 +0000 In-Reply-To: <1435573421.32500.250.camel@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: Ian Campbell Cc: Lars Kurth , suravee.suthikulpanit@amd.com, StefanoStabellini , Andrew Cooper , Dario Faggioli , Ian Jackson , Aravind Gopalakrishnan , Jan Beulich , Anthony Perard , xen-devel List-Id: xen-devel@lists.xenproject.org On 06/29/2015 06:23 AM, Ian Campbell wrote: > On Fri, 2015-06-26 at 21:07 +0100, Ian Campbell wrote: >> On Fri, 2015-06-26 at 15:36 -0400, Boris Ostrovsky wrote: >>> On 06/26/2015 10:52 AM, Jan Beulich wrote: >>>>>>> On 26.06.15 at 16:34, wrote: >>>>> I did this using rdmsr from mst-tools instead, running on a native >>>>> kernel gave: >>>>> >>>>> # for i in $(seq 0 31) ;do rdmsr -p $i MSR_K8_TOP_MEM2; done >>>>> 0 >>>>> [...] >>>>> 0 >>> Is MSR_K8_TOP_MEM2 defined somewhere in the shell? >> There is no $ there, so it wouldn't make any difference... >> >> I had foolishly assumed that rdmsr would either know the names of the >> MSRs or it would complain about a string it didn't understand which >> wasn't a number. >> >> Instead it just reads some random register which happens to be >> strtoul("MSR_K8_TOP_MEM2"), how helpful. > => https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=790075 > >>> Just to make sure, could you use explicit address, i.e. >>> >>> for i in $(seq 0 31) ;do rdmsr -p $i 0xc001001d; done > It reported 43f000000 on all processors on native (and only the first 8 > on Xen due to limited dom0 vcpus). > >>> (and if they are still all zeroes, can you read 0xc0010010 (SYSCFG) as >>> well?) > It wasn't all zeroes, but anyway, it reported 740000 on all processors > on native (I forgot to run under Xen). Thanks, so this means that we do have WB memory above 4G. (And I am not sure I understand why Jan said MTRRs show that memory above 4G is UC in http://lists.xenproject.org/archives/html/xen-devel/2015-06/msg04397.html . The log also seems to suggest that it is WB, doesn't it?) -boris