[RFC] Host1x/TegraDRM UAPI (sync points)

[Dmitry Osipenko]

29.06.2020 13:27, Mikko Perttunen пишет:
...
>>>> 3. Sync points should be properly refcounted. Job's sync points
>>>> shouldn't be re-used while job is alive.
>>>>
>>>> 4. The job's sync point can't be re-used after job's submission (UAPI
>>>> constraint!). Userspace must free sync point and allocate a new one for
>>>> the next job submission. And now we:
>>>>
>>>>     - Know that job's sync point is always in a healthy state!
>>>>
>>>>     - We're not limited by a number of physically available hardware
>>>> sync
>>>> points! Allocation should block until free sync point is available.

It also occurred to me that if allocation is blocking and if there is a
need to allocate multiple sync points for a job, then the IOCTL should
be able to allocate multiple sync points at once. This will prevent
interlock situation where two context could block on each other.