Hi Jerry,
Am 05.06.2018 um 03:50 schrieb Zhang, Jerry (Junwei):
> [SNIP]
>>
>> Can you check if the problem also vanishes when you disable the
>> following
>> optimization in amdgpu_vm_update_ptes?
>>> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â /* We don't need to update PTEs for huge pages */
>>> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â if (entry->huge)
>>> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â continue;
>> Just comment this out for a test.
>
> Thanks to point it out.
> That indeed works well too.
>
> The issue happened by missing to update PTE for reserved PRT range, if
> huge page is introduced.
>
> Not sure if below change is expected to save the huge page for PRT
> support.
> That updates the huge page and fills the correct PTE for PRT as well,
> different from current fix patch.
> {{{
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â /* We don't need to update PTEs for huge pages */
> -Â Â Â Â Â Â Â Â Â Â Â Â Â Â if (entry->huge)
> +Â Â Â Â Â Â Â Â Â Â Â Â Â Â if (entry->huge && !(flags & AMDGPU_PTE_PRT))
> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â continue;
>
> }}}
problem is that not only affects PRT, but all mappings.
See the patch here if you currently can't receive mails from amd-gfx:
https://patchwork.freedesktop.org/patch/227336/
Essentially I made a wrong assumption in the clear all code path. Please
also note that I hadn't time to fully test this patch yet.
Christian.
>
>
> Jerry
