And in fact page scrubbing *is* entirely synchronous in xen-unstable now
(but not in any stable branch, as yet).
-- Keir
On 23/09/2009 15:40, "George Dunlap" <George.Dunlap@xxxxxxxxxxxxx> wrote:
> Cancel that... the real problem was that set_pod_target() was trying
> to allocate superpages, but not falling back to 4k pages if that
> failed.
>
> -George
>
> On Wed, Sep 23, 2009 at 3:08 PM, George Dunlap
> <George.Dunlap@xxxxxxxxxxxxx> wrote:
>> I'm running into an issue where alloc_domheap_pages() fails, even
>> though there is free memory, because the memory hasn't been scrubbed
>> yet. The context of this is when ballooning down one VM in order to
>> start a second VM: the balloon driver on the first VM has reached its
>> target, but creation of the second VM fails because the freed memory
>> hasn't been scrubbed yet.
>>
>> In the situation where there is no memory on the free list, but memory
>> on the "to-be-srubbed" list, is there any reason why we don't do
>> syncronous scrubbing?
>>
>> The alternative would be to teach the control tools to look at
>> unscrubbed vs free memory, and wait until there was enough to start
>> the VM; but that seems a bit more hackish.
>>
>> I chatted with Tim Deegan about this, and the only issue he could see
>> would be making sure that hypercalls which called
>> alloc_domheap_pages() yielded reasonably.
>>
>> Thoughts?
>> -George
>>
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel