Re: [PATCH mm] mm: fix BUG with kvzalloc+GFP_ATOMIC

From: Michal Hocko
Date: Mon Sep 26 2022 - 11:48:04 EST


On Mon 26-09-22 16:20:13, Florian Westphal wrote:
> Michal Hocko <mhocko@xxxxxxxx> wrote:
> > On Mon 26-09-22 15:08:08, Florian Westphal wrote:
> > [...]
> > > To the best of my knowledge there are users of this interface that
> > > invoke it with rcu read lock held, and since those always nest, the
> > > rcu_read_unlock() won't move us to GFP_KERNEL territory.
> >
> > Fiar point. I can see a comment above rhashtable_insert_fast which is
> > supposed to be used by drivers and explicitly documented to be
> > compatible with an atomic context. So the above is clearly a no-go
> >
> > In that case I would propose to go with the patch going
> > http://lkml.kernel.org/r/YzFplwSxwwsLpzzX@xxxxxxxxxxxxxx direction.
>
> FWIW that patch works for me. Will you do a formal patch submission?

Feel free to use it and glue it to the actual bug report.

Thanks!

--
Michal Hocko
SUSE Labs