Re: [PATCH v4] Documentation/gpu: VM_BIND locking document

Thomas Hellström
2023-11-21T08:42:05Z

Hi, Boris

On 11/16/23 15:47, Boris Brezillon wrote:
> On Thu, 16 Nov 2023 14:53:50 +0100
> Thomas Hellström <thomas.hellstrom@linux.intel.com> wrote:
>
>> On Thu, 2023-11-16 at 14:27 +0100, Boris Brezillon wrote:
>>> On Thu, 16 Nov 2023 12:48:45 +0100
>>> Thomas Hellström <thomas.hellstrom@linux.intel.com> wrote:
>>>
>>>> Hi, Boris,
>>>>
>>>> Thanks for reviewing. Some comments below:
>>>>
I'm going to send out an updated version today with I think all of
Danilo's comments and must of yours addressed. While I added more
references to GPUVM, mainly as code examples and explanations, I've
intentionally left out the "This is a driver lock and this is a gpvum
lock distinction", The reason is twofold. First I think that when we get
userptr into gpvum, gpuvm needs to be aware of most if not all locks.
Second, since this document is an implementation guideline and gpuvm is
an implementation it makes more sense to me to add pointers from the
GPUVM documentation to the VM_BIND locking guideline, and that could be
a task to be looked at after merging this together with implementing the
userptr stuff. The most important thing at this point is that the
document doesn't conflict in any way with the gpuvm implementation, and
I've fixed those parts where I missed the separate lock protecting the
GEM object's vm_bo list that you pointed out.

I strongly think this is the right way to go but if you disagree to the
point where you're not willing to provide an ack or R-B, let me know and
we can look at adding what's missing.

Thanks,

Thomas