>>> + if (local_drain) {
>>> + lru_add_drain_all();
>>
>> I do wonder if that is valid to be called with all the locks at this point.
>
> This function uses per cpu workers and needs no other locks. Also verified
> with lockdep.
Okay, perfect.
>>> +/**
>>> + * To be called with the page locked or with an extra reference!
>>
>> Can we have races here? (IOW, two callers concurrently for the same page)
>
> That would be fine and is part of the design. The ultravisor calls will
> either make the page accessible or will be a (mostly) no-op.
> In fact, we allow for slight over-indication of "needs to be exported"
>
> What about:
>
> /*
> * To be called with the page locked or with an extra reference! This will
> * prevent gmap_make_secure from touching the page concurrently. Having 2
> * parallel make_page_accessible is fine, as the UV calls will become a
> * no-op if the page is already exported.
> */
Yes, much clearer, thanks!
--
Thanks,
David / dhildenb
