On 13.12.2021 11:33, Roger Pau Monné wrote:
> On Mon, Dec 13, 2021 at 11:00:23AM +0100, Jan Beulich wrote:
>> On 13.12.2021 10:45, Roger Pau Monné wrote:
>>> It would be better if we could somehow account this in a per-vCPU way,
>>> kind of similar to what we do with vPCI BAR mappings.
>>
>> But recording them per-vCPU wouldn't make any difference to the
>> number of pages that could accumulate in a single run. Maybe I'm
>> missing something in what you're thinking about here ...
>
> If Xen somehow did the free in guest vCPU context before resuming
> guest execution then you could yield when events are pending and thus
> allow other guests to run without hogging the pCPU, and the freeing
> would be accounted to vCPU sched slice time.
That's an interesting thought. Shouldn't be difficult to arrange for
HVM (from {svm,vmx}_vmenter_helper()), but I can't immediately see a
clean way of having the same for PV (short of an ad hoc call out of
assembly code somewhere after test_all_events).
Jan
