Re: [PATCH v4 0/5] cpumask: Fix invalid uniprocessor assumptions

[Andrew Morton <akpm@linux-foundation.org>]

On Sun, 03 Jul 2022 09:50:51 +0200 Sander Vanheule <sander@svanheule.net> wrote:

> On Sat, 2022-07-02 at 13:38 -0700, Andrew Morton wrote:
> > On Sat,  2 Jul 2022 18:08:23 +0200 Sander Vanheule <sander@svanheule.net> wrote:
> > 
> > > On uniprocessor builds, it is currently assumed that any cpumask will
> > > contain the single CPU: cpu0. This assumption is used to provide
> > > optimised implementations.
> > > 
> > > The current assumption also appears to be wrong, by ignoring the fact
> > > that users can provide empty cpumask-s. This can result in bugs as
> > > explained in [1].
> > 
> > It's a little unkind to send people off to some link to explain the
> > very core issue which this patchset addresses!  So I enhanced this
> > paragraph:
> > 
> > : The current assumption also appears to be wrong, by ignoring the fact that
> > : users can provide empty cpumasks.  This can result in bugs as explained in
> > : [1] - for_each_cpu() will run one iteration of the loop even when passed
> > : an empty cpumask.
> 
> Makes sense to add this, sorry for the inconvenience.
> 
> Just to make sure, since I'm not familiar with the process for patches going through the mm tree,

Patches enter -mm in quilt form and are published in the (rebasing)
mm-unstable branch
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.  Once they have
stopped changing and have been stabilized, I move them into the
non-rebasing mm-stable branch.

> can I still send a v5 to move the last patch forward in the series, and to include Yury's tags?

I already added Yury's ack.  Please tell me the specific patch ordering
and I'll take care of that.