From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Vrabel Subject: Re: a ton of kernel issues Date: Tue, 13 Dec 2011 13:17:52 +0000 Message-ID: <4EE75080.1000909@citrix.com> References: <4EE675A8.3030609@niemail.de> <4EE71663.5040308@gmail.com> <4EE72A94.6040904@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4EE72A94.6040904@gmail.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: George Shuklin Cc: xen-devel@lists.xensource.com, sandr8@gmail.com List-Id: xen-devel@lists.xenproject.org On 13/12/11 10:36, George Shuklin wrote: > On 13.12.2011 14:19, Alessandro Salvatori wrote: >> >>> pv_ops is still have some issues with memory limits, but any >>> new kernel (3.0+) will boot normal and operates with very >>> minor glitches. Older pv_ops (f.e. debian 2.6.32) have some >>> more major issues. >> what glitches should one expect with 3.0+, and having the choice, >> would it be better to go with 3.1 or even 3.2? >> >> > Right now I know about two of them: > When you set up memory for virtual machine using xenballon, value in > dom0 differ from value in domU. The issue is that -xen kernels 'hide' > some memory in 'used' memory, and pv-ops just reducing TotalMem to value > without that memory. Practically that means if you set up memory for > domain to 2GiB client will saw only 1.95GiB and so on. This really makes no practical difference. The memory is "used" is either case and the different reporting is a side-effect of the change in how certain memory allocations are done. > The second issue is lack of support of 'pre-inflated balloon', means you > can not set up memory-static-max to 2GiB, target to 1GiB and do 'memory > grow' from 1 G to 2 G latter without VM reboot. -xen kernels allow this > (up to memory-static-max limit). This should work if memory hotplug is enabled. It is also supported without memory hotplug but this requires that the tools supply a suitable memory map that covers the largest memory-static-max limit you wish to support. I'm not sure if the tools can do this yet. David