On 30.01.25 14:29, Simona Vetter wrote:
On Thu, Jan 30, 2025 at 10:28:00AM +0100, David Hildenbrand wrote:
On 30.01.25 06:34, Alistair Popple wrote:
Looking at hmm_test I see that doesn't use the sequence counter to ensure
the PTE remains valid whilst it is mapped. I think that is probably wrong, so
apologies if that lead you astray.
Yes, the hmm_test does not completely follow the same model the nouveau
implementation does; so it might not be completely correct.
But unrelated but just crossed my mind:
I guess another crucial difference is that the hw (probably, not sure)
will restart the fault if we don't repair it to its liking. So the
hmm-test does need some kind of retry loop too somewhere to match that.
Yes. Especially for the folio lock spinning is a rather suboptimal
approach. So we likely would want the option to just lock it instead of
try-locking it. (or getting rid of it entirely :) )
But might be good to also still land some of the other improvements
discussed in these threads to make make_device_exclusive a bit more
reliable instead of relying on busy-looping throug the hw fault handler
for everything.
Right.
--
Cheers,
David / dhildenb
