Re: [PATCH] rcu: Use IRQ_WORK_INIT_HARD for srcu's irq_work

On 2026-08-21 12:04:31 [+0200], To Steven Rostedt wrote:
> On 2026-08-20 13:00:28 [-0400], Steven Rostedt wrote:
> > On Thu, 20 Aug 2026 15:55:00 +0200
> > Sebastian Andrzej Siewior <[email protected]> wrote:
> > 
> > > > > diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
> > > > > index 7c2f7cc131f7a..b703233d4a63f 100644
> > > > > --- a/kernel/rcu/srcutree.c
> > > > > +++ b/kernel/rcu/srcutree.c
> > > > > @@ -218,7 +218,7 @@ static int init_srcu_struct_fields(struct srcu_struct *ssp, bool is_static)
> > > > >  	mutex_init(&ssp->srcu_sup->srcu_barrier_mutex);
> > > > >  	atomic_set(&ssp->srcu_sup->srcu_barrier_cpu_cnt, 0);
> > > > >  	INIT_DELAYED_WORK(&ssp->srcu_sup->work, process_srcu);
> > > > > -	init_irq_work(&ssp->srcu_sup->irq_work, srcu_irq_work);
> > > > > +	ssp->srcu_sup->irq_work = IRQ_WORK_INIT_HARD(srcu_irq_work);  
> > > > 
> > > > It may need a comment to not lose that.  
> > 
> > I agree a comment would be useful here.
> Urgh.

What do you want me to cover in the comment? The arguing pro
IRQ_WORK_INIT_HARD is because it is "just" a workqueue schedule and it
avoids the jump over irq_work/ thread. This makes sense regardless of
the tracing issue.
If it would be not compatible with hard-irq context I would argue for
the makefile change which is still sane since there is no other way to
express dependencies (which we clearly have here).

Sebastian