From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Limpach Subject: Re: DOM0_GETDOMAININFO intended behavior Date: Sat, 4 Jun 2005 20:42:54 +0100 Message-ID: <3d8eece205060412423cdb3a1e@mail.gmail.com> References: <200506040756.26647.dsteklof@us.ibm.com> Reply-To: Christian.Limpach@cl.cam.ac.uk Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <200506040756.26647.dsteklof@us.ibm.com> Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Daniel Stekloff Cc: Ian Pratt , xen-devel@lists.xensource.com, Kip Macy List-Id: xen-devel@lists.xenproject.org On 6/4/05, Daniel Stekloff wrote: > On Saturday 04 June 2005 01:20, Ian Pratt wrote: > > > :-) > > > > > > I asked the same question a week or two ago and yes it is > > > intended. It provides for easy iteration. I think it is kind > > > of a hackish interface as it isn't uniform with *all* the > > > other DOM0 calls. However, it works and once you know to > > > check the domid return value your code will work as expected. > > > > I suppose we could add a flag to indicate whether you were iterating or > > wanted information on a specific domain. I think currently the only cas= e > > where we want to iterate is 'xm list'. >=20 >=20 > If you're ok with changing the interface, wouldn't it be better for the > hypercall to get and return just the requested domain info while you move= the > interation to libxc? The library could have two calls, one which calls th= e > other: xc_domain_getinfo() and xc_domain_getinfo_list() This doesn't scale well if your domain id space is sparse, which it can easily become on a server which has many domains restarting frequently. This is the reason for the current behaviour. I don't see what's wrong with the current behaviour anyway, how hard is it to check if the call succeeded and then additionally check if information for the requested domain was returned? We could avoid the additional check by having a different return code for when the call succeeded but returned information for a different domain than the requested one. christian