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From:   Joel Fernandes <joel@joelfernandes.org>
Date:   Wed, 5 Jun 2019 09:04:44 -0400
Message-ID: <CAEXW_YTsT5BY5Qbc6Jju2XmbHSQFELrGM9UaPPXY-ETmJaBrsA@mail.gmail.com>
Subject: Re: [RFC 4/6] workqueue: Convert for_each_wq to use built-in list check
To:     Daniel Jordan <daniel.m.jordan@oracle.com>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
        Bjorn Helgaas <bhelgaas@google.com>,
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On Tue, Jun 4, 2019 at 9:25 PM Daniel Jordan <daniel.m.jordan@oracle.com> wrote:
>
> On Sat, Jun 01, 2019 at 06:27:36PM -0400, Joel Fernandes (Google) wrote:
> > list_for_each_entry_rcu now has support to check for RCU reader sections
> > as well as lock. Just use the support in it, instead of explictly
> > checking in the caller.
> >
> > Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
> > ---
> >  kernel/workqueue.c | 5 ++---
> >  1 file changed, 2 insertions(+), 3 deletions(-)
> >
> > diff --git a/kernel/workqueue.c b/kernel/workqueue.c
> > index 9657315405de..91ed7aca16e5 100644
> > --- a/kernel/workqueue.c
> > +++ b/kernel/workqueue.c
> > @@ -424,9 +424,8 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq);
> >   * ignored.
> >   */
> >  #define for_each_pwq(pwq, wq)                                                \
> > -     list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node)          \
> > -             if (({ assert_rcu_or_wq_mutex(wq); false; })) { }       \
> > -             else
> > +     list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node,          \
> > +                              lock_is_held(&(wq->mutex).dep_map))
> >
>
> I think the definition of assert_rcu_or_wq_mutex can also be deleted.

Sure, will do. Thank you.