Re: [Xen-devel] [PATCH] Don't track all memory when enabling log dirty to track vram

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 17.02.14 at 15:51, George Dunlap <george.dunlap@xxxxxxxxxxxxx> wrote:
> On 02/17/2014 10:18 AM, Jan Beulich wrote:
>> Actually I'm afraid there are two problems with this patch:
>>
>> For one, is enabling "global" log dirty mode still going to work
>> after VRAM-only mode already got enabled? I ask because the
>> paging_mode_log_dirty() check which paging_log_dirty_enable()
>> does first thing suggests otherwise to me (i.e. the now
>> conditional setting of all p2m entries to p2m_ram_logdirty would
>> seem to never get executed). IOW I would think that we're now
>> lacking a control operation allowing the transition from dirty VRAM
>> tracking mode to full log dirty mode.
> 
> Hrm, will so far playing with this I've been unable to get a localhost 
> migrate to fail with the vncviewer attached.  Which seems a bit strange...

Not necessarily - it may depend on how the tools actually do this:
They might temporarily disable log dirty mode altogether, just to
re-enable full mode again right away. But this specific usage of the
hypervisor interface wouldn't (to me) mean that other tool stacks
might not be doing this differently.

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel