From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Olivier B." Subject: Re: [PATCH] Re: tmem on 4.1 (was Re: Freeze schedule) Date: Thu, 20 Jan 2011 09:07:47 +0100 Message-ID: <4D37ED53.6000202@daevel.fr> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org Le 20/01/2011 08:17, Keir Fraser a =E9crit : > On 19/01/2011 21:38, "Dan Magenheimer" wro= te: > >> Just to check again, has anyone actually seen a problem with >> tmem enabled by default recently? I agree that there is still >> theoretically a problem, but there is the same problem with >> normal guests doing lots of ballooning as well. Also, note >> that even if tmem defaults to enabled, the problem is impossible >> unless a guest enables tmem (or, in the case of SuSE, dom0). >> And even if a guest does enable tmem, the problem manifested >> largely due to shadow pages using order>0 (now fixed?)... >> failure on domain creation can happen for many reasons and >> is much less of an issue, true? >> >> Feel free to shoot me down with more evidence, but I have >> to at least provide token resistance to this patch. Distros >> might certainly choose to disable it to avoid any risk at >> all, but turning it off anymore seems overkill for xen.org >> open source Xen IMHO. > > Tbh I was wondering whether anyone is really using it in earnest. No > upstream kernels support it? If noone's using it, who really cares whet= her > it's enabled or not, apart from its author. > > -- Keir > Well, it is present but disabled in the new Debian Squeeze kernel... and=20 as there is no documentation, there is no chance to see it enabled. I had to search on the xen lists to find how to enable that. For example : http://www.google.fr/search?hl=3Dfr&source=3Dhp&q=3Dtmem_compress We should maybe add info about tmem on the Xen Wiki, no ? Olivier