Re: [PATCH mm-unstable] lib/Kconfig.debug: do not enable DEBUG_PREEMPT by default

[Hyeonggon Yoo]

On Mon, Jan 23, 2023 at 12:05:00PM +0100, Christoph Lameter wrote:
> On Sat, 21 Jan 2023, Hyeonggon Yoo wrote:
> 
> > Whew, I still get confused about who to Cc, thanks for adding them.
> > and I also didn't include the percpu memory allocator maintainers, who may
> > have opinion. let's add them too.
> 
> Well looks ok to me.

Thanks for looking at!

> However, I thought most distro kernels disable PREEMPT anyways for
> performance reasons? So DEBUG_PREEMPT should be off as well. I guess that
> is why this has not been an issue so far.

It depends on PREEMPTION, and PREEMPT_DYNAMIC ("Preemption behaviour defined on boot")
selects PREEMPTION even if I end up using PREEMPT_VOLUNTARY.

Not so many distros use DEBUG_PREEMPT, but I am occationally hit by this
because debian and fedora enabled it :)