From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [PATCH 2/4] libxc: report how much memory a domain has on each NUMA node Date: Mon, 10 Mar 2014 17:09:49 +0000 Message-ID: <531DF1DD.1090803@citrix.com> References: <20140305143357.6984.7729.stgit@Solace> <20140305143635.6984.34422.stgit@Solace> <21277.60093.406016.679465@mariner.uk.xensource.com> <1394471250.17832.11.camel@Solace> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============8967749946032943820==" Return-path: In-Reply-To: <1394471250.17832.11.camel@Solace> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Dario Faggioli Cc: Ian Campbell , Juergen Gross , Ian Jackson , xen-devel , Jan Beulich , Daniel De Graaf List-Id: xen-devel@lists.xenproject.org --===============8967749946032943820== Content-Type: multipart/alternative; boundary="------------030109020406060407040302" --------------030109020406060407040302 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit On 10/03/14 17:07, Dario Faggioli wrote: > On lun, 2014-03-10 at 16:39 +0000, Ian Jackson wrote: >> Dario Faggioli writes ("[PATCH 2/4] libxc: report how much memory a domain has on each NUMA node"): >> >> What are callers supposed to do about discrepancies between the two >> sets of information ? >> > I'm sorry, what discrepancies? Without holding a big spinlock in Xen, the results from each hypercall might not sum to the size of the machine. There is no acceptable solution for this AFAICT. ~Andrew --------------030109020406060407040302 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: 8bit On 10/03/14 17:07, Dario Faggioli wrote:
> On lun, 2014-03-10 at 16:39 +0000, Ian Jackson wrote:
>> Dario Faggioli writes ("[PATCH 2/4] libxc: report how much memory a domain has on each NUMA node"):
>>
>> What are callers supposed to do about discrepancies between the two
>> sets of information ?
>>
> I'm sorry, what discrepancies?

Without holding a big spinlock in Xen, the results from each hypercall might not sum to the size of the machine.  There is no acceptable solution for this AFAICT.

~Andrew

--------------030109020406060407040302-- --===============8967749946032943820== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel --===============8967749946032943820==--