From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yang Hongyang Subject: Re: save & restore failed when tmem enabled in Xen 4.1 & Xen 4.3 Date: Tue, 9 Jun 2015 15:06:40 +0800 Message-ID: <55769080.80706@cn.fujitsu.com> References: <20150605184501.GA21113@l.oracle.com> <5571F1E5.2070407@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; Format="flowed" Content-Transfer-Encoding: quoted-printable Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1Z2Dcc-0003Hr-Fz for xen-devel@lists.xenproject.org; Tue, 09 Jun 2015 07:06:54 +0000 In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: yunfang tai , Andrew Cooper Cc: xen-devel@lists.xenproject.org List-Id: xen-devel@lists.xenproject.org On 06/08/2015 02:30 PM, yunfang tai wrote: > Hi Andrew, > Thank you for your reply! > I do not know much about migration V2. Was it integrated to Xen? If > integrated, from which version? It's intended to be integrated to Xen4.6. However, the libxc part has alrea= dy been merged into upstream, but the libxl part still work in progress. > Thank you!! > > Best Regards, > Yunfang > > 2015-06-06 3:00 GMT+08:00 Andrew Cooper >: > > On 05/06/15 19:45, Konrad Rzeszutek Wilk wrote: > > On Thu, Jun 04, 2015 at 10:27:06PM +0800, yunfang tai wrote: > >> Hi all, > > Hey! > >> Recently, I am testing the TMEM support on Xen. I discovered = that when > >> enabled TMEM in ubuntu 14.10 as guest on Xen 4.1 & Xen 4.3, "xm s= ave" & "xm > >> restore=93 failed after there are more than 1000 pages put in per= sistent pool > >> of TMEM in Xen. My operations are list as follows: > > Is it exactly 1000 or just about? I presume it does not matter how= much but > > that you discovered it by having 1000 of them? > > > >> In ubuntu guest (8 cores , 8GB): > >> sudo modprobe tmem > >> (than wait for the selfballoon to finish) > >> dd if=3D/dev/zero of=3D/tmp/test.img bs=3D10M count=3D1000 > >> dd if=3D/tmp/test.img of=3D/dev/null bs=3D10M > >> dd if=3D/tmp/test.img of=3D/dev/null bs=3D10M > >> ......... > >> (until more than 1000 pages put in persistent pool) > >> In Domain 0: > >> (add tmem in grub.cfg) > >> xm save ubuntu test.save > >> xm restore ubuntu test.save > >> > >> When TMEM is not enabled, save & restore success after these oper= ations. > >> But if TMEM is enabled, save & restore fail. > > Are there any errors from the logs? Anything? > >> Does anyone test about save & restore when enabled TMEM in Xen?? = Is there > >> anything I do wrong? > > Well lets see what broke. But I think Andrew discovered that the > > migration protocol when it came to 'tmem' was not up to snuff. CC-= ing him > > just to confirm. > > > > (Andrew, for the persistent part of this - it conceptually should > > get all of the tmem memory that pushed to the hypervisor back in t= he > > image. When you were looking at migrationv2 did you just skim thro= ugh > > that or mostly ignored it?) > > Took a look at the code, attempted to figure out what was going on, t= hen > decided to ignore it for the time being. > > As a baseline, there is no error checking of hypercalls or their > returned data putting the data into the stream. > > Migration v2 currently has no TMEM support, and I would suggest > re-implementing it from scratch over attempting to port what currently > exists for legacy. > > ~Andrew > > > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel > -- = Thanks, Yang.