Re: [PATCH v6] random: defer fast pool mixing to worker

[Sebastian Andrzej Siewior]

On 2022-02-13 18:37:33 [+0100], Jason A. Donenfeld wrote:
> I started looking at this and came up with this draft with questions:
> https://git.kernel.org/pub/scm/linux/kernel/git/crng/random.git/commit/?h=jd/no-irq-trylocks

to
| - Does anything anywhere call get_random_xx() before the worker has a
|   chance to run?

Once you queue a work item I don't think that the scheduler needs to put
it on the CPU right away. It may have already have other tasks waiting
including some with a RT priority.
Also, the lock is irqsave() so they can be users in an interrupt
handler. I remember the original reason why I made it irqsave is because
something did kmalloc() and SLUB somehow asked for random bits.

> Some research remains...
> 
> Jason

Sebastian