Re: [PATCH v2] mm/page_isolation: fix a deadlock with printk()

Michal Hocko
2019-10-10T10:59:31Z

On Thu 10-10-19 05:01:44, Qian Cai wrote:
>
>
> > On Oct 9, 2019, at 12:23 PM, Michal Hocko <mhocko@kernel.org> wrote:
> >
> > If this was only about the memory offline code then I would agree. But
> > we are talking about any printk from the zone->lock context and that is
> > a bigger deal. Besides that it is quite natural that the printk code
> > should be more universal and allow to be also called from the MM
> > contexts as much as possible. If there is any really strong reason this
> > is not possible then it should be documented at least.
>
> Where is the best place to document this? I am thinking about under
> the “struct zone” definition’s lock field in mmzone.h.

I am not sure TBH and I do not think we have reached the state where
this would be the only way forward.

--
Michal Hocko
SUSE Labs