Re: linux-next boot error: WARNING: workqueue cpumask: online intersect > possible intersect

From: Dmitry Vyukov
Date: Fri Nov 08 2019 - 07:47:12 EST


On Wed, Jul 24, 2019 at 7:43 PM Tejun Heo <tj@xxxxxxxxxx> wrote:
>
> On Wed, Jul 24, 2019 at 10:41:29AM -0700, Eric Biggers wrote:
> > The real boot error "general protection fault in dma_direct_max_mapping_size" is
> > fixed in mainline now. I believe that unblocks syzbot testing, since it doesn't
> > appear to have been blocked by "WARNING: workqueue cpumask: online intersect >
> > possible intersect" by itself.
> >
> > Anyway: Tejun and Michael, any other ideas for why "WARNING: workqueue cpumask:
> > online intersect > possible intersect" is still happening?
>
> That code hasn't changed in years. It gotta be changes in cpumask
> initialization ordering or sth like that. The easiest way to find the
> culprit would be bisecting. I can't get to it right now. Anyone
> interested?

syzkaller will now ignore this warning as it happens on every boot and
masks all other boot problems:
https://github.com/google/syzkaller/commit/31b7aac4626757ae0862971db78aaa1338541227
syzbot will never remind about this again:
#syz invalid