Re: [PATCH] preempt-kernel on 2.4.19-pre2-ac2 bugfix

Mike Fedyk
2002-03-05T00:40:53Z

On Mon, Mar 04, 2002 at 07:23:10PM -0500, Robert Love wrote:
> The same schedule_tail bug affecting 2.5 affects 2.4 with O(1). I.e.,
> 2.4.19-pre2-ac2.
>
> In recent O(1) scheduler releases, an optimization was made that removed
> schedule_tail from UP kernels. This causes the initial preempt_count of
> a new task, which starts at 1, to never decrement to zero and thus never
> become preemptible. CONFIG_PREEMPT requires schedule_tail, too.
>
> Users of 2.4+O(1)+preempt (i.e. -ac) should use this patch:
>

I believe you want to say that O(1)sched is in -ac, and this patch will add
preempt on top of that, not that preempt is already in -ac (unless I missed
something...)

Mike