Nouveau - Feb 2021 - drm/nouneau: 5.11 cycle regression bisected to 461619f5c324 "drm/nouveau: switch to new allocator"

Am 10.02.21 um 11:46 schrieb Mike Galbraith:
> On Wed, 2021-02-10 at 11:34 +0100, Christian K?nig wrote:
>> What seems to happen here is that your system is low on resources and
we
>> just try to free up pages.
> FWIW, box has oodles generic ram free right after boot.
Then I have no idea what happens here.

The returned pages are identical, only the overhead to allocate them is 
reduced significantly.

The only other idea I have is that this somehow changes the timing and 
exposes a bug somewhere else.

You could try to replace the "for (order = min(MAX_ORDER - 1UL, 
__fls(num_pages)); num_pages;" in ttm_pool_alloc() with "for (order =
0;
num_pages;" to get the old behavior.

Regards,
Christian.
>
> 	-Mike
>

On Wed, 2021-02-10 at 11:52 +0100, Christian K?nig
wrote:
>
>
> You could try to replace the "for (order = min(MAX_ORDER - 1UL,
> __fls(num_pages)); num_pages;" in ttm_pool_alloc() with "for
(order = 0;
> num_pages;" to get the old behavior.
That's a nogo too.

	-Mike