> On Jun 15, 2020, at 1:56 PM, Luck, Tony <tony.l...@intel.com> wrote:
>
>
>>
>> Are we planning to keep PASID live once a task has used it once or are we
>> going to swap it lazily? If the latter, a percpu variable might be better.
>
> Current plan is "touch it once and the task owns it until exit(2)"
>
> Maybe someday in the future when we have data on how applications
> actually use accelerators we could look at something more complex
> if usage patterns look like it would be beneficial.
>
>
So what’s the RDMSR for? Surely you
have some state somewhere that says “this task has a PASID.” Can’t you just
make sure that stays in sync with the MSR? Then, on #GP, if the task already
has a PASID, you know the MSR is set.
