Re: [PATCH 1/2] workqueue: Use normal rcu

Tejun Heo
2019-03-22T17:43:41Z

Hello,

On Thu, Mar 21, 2019 at 09:59:35PM +0100, Sebastian Andrzej Siewior wrote:
> On 2019-03-13 17:55:47 [+0100], To linux-kernel@vger.kernel.org wrote:
> > From: Thomas Gleixner <tglx@linutronix.de>
> >
> > There is no need for sched_rcu. The undocumented reason why sched_rcu
> > is used is to avoid a few explicit rcu_read_lock()/unlock() pairs by
> > the fact that sched_rcu reader side critical sections are also protected
> > by preempt or irq disabled regions.
> >
> > Replace rcu_read_lock_sched with rcu_read_lock and acquire the RCU lock
> > where it is not yet explicit acquired. Replace local_irq_disable() with
> > rcu_read_lock(). Update asserts.
> >
> > Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> > [bigeasy: mangle changelog a little]
> > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
>
> A gentle ping.

We can switch but it doesn't really say why we'd want to. Can you
please explain why this is better?

Thanks.

--
tejun