Re: [patch 00/14] tasklets: Replace the spin wait loops and make it RT safe

From: Peter Zijlstra
Date: Tue Mar 09 2021 - 09:06:12 EST


On Tue, Mar 09, 2021 at 09:42:03AM +0100, Thomas Gleixner wrote:
> This is a follow up to the review comments of the series which makes
> softirq processing PREEMPT_RT safe:
>
> https://lore.kernel.org/r/20201207114743.GK3040@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>
> Peter suggested to replace the spin waiting in tasklet_disable() and
> tasklet_kill() with wait_event(). This also gets rid of the ill defined
> sched_yield() in tasklet_kill().
>
> Analyzing all usage sites of tasklet_disable() and tasklet_unlock_wait() we
> found that most of them are safe to be converted to a sleeping wait.
>
> Only a few instances invoke tasklet_disable() from atomic context. A few
> bugs which have been found in course of this analysis have been already
> addressed seperately.

Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>