From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ryan Harper Subject: Re: [PATCH] enforce dom0 cpus and balloon out memory Date: Fri, 29 Jul 2005 10:43:24 -0500 Message-ID: <20050729154324.GH8702@us.ibm.com> References: <9cde8bff05072820043a496e14@mail.gmail.com> <20050729151720.GF8702@us.ibm.com> <200507291624.53418.mark.williamson@cl.cam.ac.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <200507291624.53418.mark.williamson@cl.cam.ac.uk> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Mark Williamson Cc: Ian Pratt , xen-devel@lists.xensource.com, Ryan Harper List-Id: xen-devel@lists.xenproject.org * Mark Williamson [2005-07-29 10:25]: > > You could use vcpu-hotplug to drop the extra cpus from dom0 instead of > > writing directly into sysfs. The only stopper to that approach is the > > fact that dom0's self.channel is not initialized when xend starts and > > subsequently doesn't send the control message. Channels are initialized > > when a domain is built, but since dom0 is built by xen, the routine > > which sets up channels isn't called for dom0. Haven't found a good place > > for xend to initialized the channel for dom0 yet either. > > Hmmm. Is the channel never set up then? It'd certainly be nice if it were: Correct. As mentioned above, this is only a problem for dom0 since the xend contruct_image() code isn't called for dom0 as xen is the builder. The fix is as simple as calling create_channel() from dom0's XendDomInfo object. I've not determined the appropriate location to issue the call. > then you can use "xm balloon" to set dom0's memory footprint, which is > preferable to using the /proc interface directly. Indeed. Same goes for using vcpu_hotplug() versus sysfs -- Ryan Harper Software Engineer; Linux Technology Center IBM Corp., Austin, Tx (512) 838-9253 T/L: 678-9253 ryanh@us.ibm.com