From mboxrd@z Thu Jan 1 00:00:00 1970 From: George Dunlap Subject: Re: [PATCH] xen/tmem: Don't use map_domain_page for long-life-time pages. Date: Thu, 13 Jun 2013 14:56:41 +0100 Message-ID: <51B9CF99.6000407@eu.citrix.com> References: <1371127820-23294-1-git-send-email-konrad.wilk@oracle.com> <51B9C7FB.6000903@eu.citrix.com> <51B9E9ED02000078000DDEC4@nat28.tlf.novell.com> <1371131752.24512.541.camel@zakaz.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1371131752.24512.541.camel@zakaz.uk.xensource.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: Dan Magenheimer , xen-devel@lists.xensource.com, Konrad Rzeszutek Wilk , Konrad Rzeszutek Wilk , Bob Liu , keir.xen@gmail.com, Jan Beulich List-Id: xen-devel@lists.xenproject.org On 13/06/13 14:55, Ian Campbell wrote: > On Thu, 2013-06-13 at 14:49 +0100, Jan Beulich wrote: >>>>> On 13.06.13 at 15:24, George Dunlap wrote: >>> Did I understand correctly that the map_domain_page() was required on >>> >5TiB systems, presumably because of limited virtual address space? In >>> which case this code will fail on those systems? >>> >>> If that is the case, then we need to have a way to make sure tmem cannot >>> be enabled on such systems. >> Tmem is full of assumptions that all memory is mapped, and hence >> one of the requirements here was to disable tmem when that >> assumption is not true (until eventually tmem would get fixed). > Isn't this change moving it further away from that fixed state though? Perhaps, but it's probably the best change for 4.3 at this point. -George