Re: [PATCH wq/for-6.9] workqueue: Fix queue_work_on() with BH workqueues

From: Linus Torvalds
Date: Wed Feb 14 2024 - 14:04:18 EST


On Wed, 14 Feb 2024 at 10:39, Tejun Heo <tj@xxxxxxxxxx> wrote:
>
> When queue_work_on() is used to queue a BH work item on a remote CPU, the
> work item is queued on that CPU but kick_pool() raises softirq on the local
> CPU.

Now, does it make a lot of sense to ask to queue a BH work on another
CPU in the first place?

I don't think tasklets supported that. And while the workqueues
obviously do - and you fix that case - I wonder if we shouldn't say
"that operation makes no sense, please don't do it" rather than
actually support it?

What made you notice this issue?

Linus