Re: [PATCH 1/6] drivers/md/raid5: Use irqsave variant of atomic_dec_and_lock()

From: Shaohua Li
Date: Mon Jul 16 2018 - 21:24:11 EST


On Mon, Jul 16, 2018 at 02:27:40PM +0200, Sebastian Andrzej Siewior wrote:
> On 2018-07-03 22:01:36 [+0200], To linux-kernel@xxxxxxxxxxxxxxx wrote:
> > From: Anna-Maria Gleixner <anna-maria@xxxxxxxxxxxxx>
> >
> > The irqsave variant of atomic_dec_and_lock handles irqsave/restore when
> > taking/releasing the spin lock. With this variant the call of
> > local_irq_save is no longer required.
>
> Shaohua, are you with this?

Acked-by: Shaohua Li <shli@xxxxxxxxxx>
> > Cc: Shaohua Li <shli@xxxxxxxxxx>
> > Cc: linux-raid@xxxxxxxxxxxxxxx
> > Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> > Signed-off-by: Anna-Maria Gleixner <anna-maria@xxxxxxxxxxxxx>
> > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
> > ---
> > drivers/md/raid5.c | 5 ++---
> > 1 file changed, 2 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> > index 2031506a0ecd..e933bff9459e 100644
> > --- a/drivers/md/raid5.c
> > +++ b/drivers/md/raid5.c
> > @@ -409,16 +409,15 @@ void raid5_release_stripe(struct stripe_head *sh)
> > md_wakeup_thread(conf->mddev->thread);
> > return;
> > slow_path:
> > - local_irq_save(flags);
> > /* we are ok here if STRIPE_ON_RELEASE_LIST is set or not */
> > - if (atomic_dec_and_lock(&sh->count, &conf->device_lock)) {
> > + if (atomic_dec_and_lock_irqsave(&sh->count, &conf->device_lock, flags)) {
> > INIT_LIST_HEAD(&list);
> > hash = sh->hash_lock_index;
> > do_release_stripe(conf, sh, &list);
> > spin_unlock(&conf->device_lock);
> > release_inactive_stripe_list(conf, &list, hash);
> > + local_irq_restore(flags);
> > }
> > - local_irq_restore(flags);
> > }
> >
> > static inline void remove_hash(struct stripe_head *sh)
> > --
> > 2.18.0
> >