Re: [RFC PATCH 00/86] Make the kernel preemptible

From: Steven Rostedt
Date: Tue Nov 07 2023 - 19:00:22 EST


On Tue, 07 Nov 2023 15:43:40 -0800
Ankur Arora <ankur.a.arora@xxxxxxxxxx> wrote:

>
> The TIF_NEED_RESCHED flag is evaluated at all three of the preemption
> points. TIF_NEED_RESCHED_LAZY only needs to be evaluated at ret-to-user.
>
> ret-to-user ret-to-kernel preempt_count()
> NEED_RESCHED_LAZY Y N N
> NEED_RESCHED Y Y Y
>
> Based on how various preemption models set the flag they would cause
> preemption at:

I would change the above to say "set the NEED_SCHED flag", as "set the
flag" is still ambiguous. Or am I still misunderstanding the below table?

>
> ret-to-user ret-to-kernel preempt_count()
> none Y N N
> voluntary Y Y Y
> full Y Y Y
>

-- Steve