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Date:   Thu, 13 May 2021 04:48:07 +0000
From:   Dennis Zhou <dennis@kernel.org>
To:     Nikolay Borisov <nborisov@suse.com>
Cc:     tj@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] percpu_ref: Don't opencode percpu_ref_is_dying
Message-ID: <YJyvh4iE6sVEEaHD@google.com>
References: <20210511131633.185463-1-nborisov@suse.com>
 <YJqLY1FsMSf1fDq3@google.com>
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On Tue, May 11, 2021 at 01:49:23PM +0000, Dennis Zhou wrote:
> Hello,
> 
> On Tue, May 11, 2021 at 04:16:33PM +0300, Nikolay Borisov wrote:
> > Signed-off-by: Nikolay Borisov <nborisov@suse.com>
> > ---
> >  lib/percpu-refcount.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c
> > index a1071cdefb5a..af9302141bcf 100644
> > --- a/lib/percpu-refcount.c
> > +++ b/lib/percpu-refcount.c
> > @@ -275,7 +275,7 @@ static void __percpu_ref_switch_mode(struct percpu_ref *ref,
> >  	wait_event_lock_irq(percpu_ref_switch_waitq, !data->confirm_switch,
> >  			    percpu_ref_switch_lock);
> >  
> > -	if (data->force_atomic || (ref->percpu_count_ptr & __PERCPU_REF_DEAD))
> > +	if (data->force_atomic || percpu_ref_is_dying(ref))
> >  		__percpu_ref_switch_to_atomic(ref, confirm_switch);
> >  	else
> >  		__percpu_ref_switch_to_percpu(ref);
> > @@ -385,7 +385,7 @@ void percpu_ref_kill_and_confirm(struct percpu_ref *ref,
> >  
> >  	spin_lock_irqsave(&percpu_ref_switch_lock, flags);
> >  
> > -	WARN_ONCE(ref->percpu_count_ptr & __PERCPU_REF_DEAD,
> > +	WARN_ONCE(percpu_ref_is_dying(ref),
> >  		  "%s called more than once on %ps!", __func__,
> >  		  ref->data->release);
> >  
> > @@ -465,7 +465,7 @@ void percpu_ref_resurrect(struct percpu_ref *ref)
> >  
> >  	spin_lock_irqsave(&percpu_ref_switch_lock, flags);
> >  
> > -	WARN_ON_ONCE(!(ref->percpu_count_ptr & __PERCPU_REF_DEAD));
> > +	WARN_ON_ONCE(!percpu_ref_is_dying(ref));
> >  	WARN_ON_ONCE(__ref_is_percpu(ref, &percpu_count));
> >  
> >  	ref->percpu_count_ptr &= ~__PERCPU_REF_DEAD;
> > -- 
> > 2.25.1
> > 
> 
> If no one has any objections to me officially taking percpu_ref, I'll
> pick this up.
> 
> Thanks,
> Dennis

I've applied this to for-5.13-fixes.

Thanks,
Dennis