[PATCH 5/8] sync_file: add support for a semaphore object

[Dave Airlie]

>>
>> Not sure what the best semantics are there, any opinions on barring
>> wakeups/polling on semaphore sync_files, and just punting this
>> until we need it.
>
> I think getting it right now will make writing sw_sync-esque (i.e. cpu)
> tests easier and more complete.

I just don't have any use case for it, so we would be writing code to
write tests for it.

That doesn't seem smart.

If there is a future non-testing use case, the API is expressive
enough for someone
to add a flag or new sync obj to allow polling and to add support in a
nice easily
digestible patch.

Dave.