From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Xu, Dongxiao" Subject: Re: Xen Platform QoS design discussion Date: Fri, 2 May 2014 12:30:24 +0000 Message-ID: <40776A41FC278F40B59438AD47D147A9119F4EF4@SHSMSX104.ccr.corp.intel.com> References: <40776A41FC278F40B59438AD47D147A9119F3FEA@SHSMSX104.ccr.corp.intel.com> <1398877340.5166.13.camel@kazak.uk.xensource.com> <40776A41FC278F40B59438AD47D147A9119F42A2@SHSMSX104.ccr.corp.intel.com> <5363804B020000780000E604@mail.emea.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5363804B020000780000E604@mail.emea.novell.com> Content-Language: en-US List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich Cc: "Andrew Cooper(andrew.cooper3@citrix.com)" , Ian Campbell , "xen-devel@lists.xen.org" List-Id: xen-devel@lists.xenproject.org > -----Original Message----- > From: Jan Beulich [mailto:JBeulich@suse.com] > Sent: Friday, May 02, 2014 5:24 PM > To: Xu, Dongxiao > Cc: Andrew Cooper(andrew.cooper3@citrix.com); Ian Campbell; > xen-devel@lists.xen.org > Subject: RE: Xen Platform QoS design discussion > > >>> On 01.05.14 at 02:56, wrote: > >> From: Ian Campbell [mailto:Ian.Campbell@citrix.com] > >> Have you asked yourself whether this information even needs to be > >> exposed all the way up to libxl? Who are the expected consumers of this > >> interface? Are they low-level CLI tools (i.e. like xenpm is) or are you > >> expecting toolstacks to plumb this information all the way up to their > >> GUI or CLI (e.g. xl or virsh)? > > > > The information returned to libxl users is the cache utilization for a > > certain domain in certain socket, and the main consumers are cloud users like > > openstack, etc. Of course, we will also provide an xl command to present such > > information. > > To me this doesn't really address the question Ian asked, yet knowing > who's going to be the consumer of the data is also quite relevant for > answering your original question on the method to obtain that data. > Obviously, if the main use of it is per-domain, a domctl would seem like > a suitable approach despite the data being more of sysctl kind. But if > a global view would be more important, that model would seem to make > life needlessly hard for the consumers. In turn, if using a domctl, I tend > to agree that not using shared pages would be preferable; iirc their use > was mainly suggested because of the size of the data. >>From the discussion with openstack developers, on certain cloud host, all running VM's information (e.g., domain ID) will be stored in a database, and openstack software will use libvirt/XenAPI to query specific domain information. That libvirt/XenAPI API interface basically accepts the domain ID as input parameter and get the domain information, including the platform QoS one. Based on above information, I think we'd better design the QoS hypercall per-domain. Thanks, Dongxiao > > Jan