Re: [RFC PATCH] xprtrdma: Move long delayed work on system_dfl_long_wq

[Chuck Lever]

On Thu, Apr 30, 2026, at 11:04 AM, Frederic Weisbecker wrote:
> Le Thu, Apr 30, 2026 at 10:05:52AM -0400, Chuck Lever a écrit :

>> Does the patch address a bug (work isn't getting rescheduled at
>> all) or is it merely a minor optimization for certain platforms?
>> 
>> What's the user-visible issue that will be improved with this
>> change?
>
> It's not a bug, it's an optimization power-wise and performance-wise
> and also part of a bigger sanity change:
>
> - Long works have no reason to stick to a single CPU. If they are converted to
>   be unbound, the scheduler can move them to relevant targets to optimize
>   performances and power consumption. Hence the new system_unbound_long_wq.
>   The goal is to remove system_long_wq if none of its users rely on locality.
>
> - Using queue_delayed_work() with a bound workqueue doesn't make any sense
>   since the target is completely random.

The light dawns (for me). That's what I'd like to see in the commit message.

I don't have any technical objections to the code change.


-- 
Chuck Lever