Re: [RFC PATCH 7/7] mm/slab: make kfree_rcu_nolock() work with sheaves

[Harry Yoo <harry.yoo@oracle.com>]

On Thu, Feb 12, 2026 at 11:15:52AM -0800, Alexei Starovoitov wrote:
> On Fri, Feb 6, 2026 at 1:35 AM Harry Yoo <harry.yoo@oracle.com> wrote:
> >
> >         } else {
> > +               if (unlikely(!allow_spin)) {
> > +                       /* call_rcu() does not support NMI context */
> > +                       rcu_sheaf->size--;
> > +                       local_unlock(&s->cpu_sheaves->lock);
> > +                       goto fail;
> 
> As a first step it's ok, but we need to make call_rcu() work too.

Yeah I was thinking it would be nice to have call_rcu_nolock()...

> Shouldn't be too hard. It protects itself with local_irq_save,
> so if (irqs_disabled()) defer to irq_work and call_rcu there
> or guard reentrance into __call_rcu_common() with per-cpu busy counter.
> rcu_head can be reused to form list of objects to be processed in irq work.

I'll take a look at that, thanks!

-- 
Cheers,
Harry / Hyeonggon