Re: [PATCH v5 11/14] gpu: nova-core: gsp: cmdq: use consume_element to implement drain

[John Hubbard <jhubbard@nvidia.com>]

On 10/20/26 8:23 PM, Eliot Courtney wrote:
> On Wed Oct 21, 2026 at 12:12 PM JST, John Hubbard wrote:
>> On 10/20/26 7:57 PM, Eliot Courtney wrote:
>>> On Tue Oct 20, 2026 at 11:27 PM JST, Alexandre Courbot wrote:
>>>> On Tue Oct 20, 2026 at 7:18 PM JST, sashiko-bot wrote:
>>> [...]
>>> I'm also fine with special casing `wait_for_msg`, but personally
>>> (maybe) sleeping when you set timeout to Delta::ZERO sounds busted to
>>> me.
>>
>> It's not necessarily wrong, depending on how you think about it:
>> "sleep, but timeout at zero" is something I've seen used (I forget
>> where) as to mean "context switch away", kind of like a cpu_relax().
> 
> Here, it only sometimes sleeps ("(maybe)"), depending on the resolution
> of the timer and how long stuff takes. So it's really pretty
> inconsistent IMO.

Yes it is going to act in ways that look non-deterministic. And that's
OK, because:

a) It's not broken.

b) It's not unreasonable nor even terribly surprising behavior: one
can reason about it.

c) The requested behavior itself is impossible: "do X for an infinitely
short amount of time".

Why are we adding code to optimize behavior for callers that should
not even exist?

thanks,
-- 
John Hubbard