Re: [PATCH] mm/page_alloc: Add a reason for reserved pages in has_unmovable_pages()

[Qian Cai]

On Fri, 2019-10-04 at 15:07 +0200, Michal Hocko wrote:
> On Fri 04-10-19 08:56:16, Qian Cai wrote:
> [...]
> > It might be a good time to rethink if it is really a good idea to dump_page()
> > at all inside has_unmovable_pages(). As it is right now, it is a a potential
> > deadlock between console vs memory offline. More details are in this thread,
> > 
> > https://lore.kernel.org/lkml/1568817579.5576.172.camel@xxxxxx/
> 
> Huh. That would imply we cannot do any printk from that path, no?

Yes, or use something like printk_deferred() or it needs to rework of the
current console locking which I have no clue yet.