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Date:   Mon, 27 Jun 2022 13:59:07 -0700
From:   "Paul E. McKenney" <paulmck@kernel.org>
To:     Uladzislau Rezki <urezki@gmail.com>
Cc:     "Joel Fernandes (Google)" <joel@joelfernandes.org>,
        rcu@vger.kernel.org, linux-kernel@vger.kernel.org,
        rushikesh.s.kadam@intel.com, neeraj.iitr10@gmail.com,
        frederic@kernel.org, rostedt@goodmis.org, vineeth@bitbyteword.org
Subject: Re: [PATCH v2 8/8] rcu/kfree: Fix kfree_rcu_shrink_count() return
 value
Message-ID: <20220627205907.GM1790663@paulmck-ThinkPad-P17-Gen-1>
Reply-To: paulmck@kernel.org
References: <20220622225102.2112026-1-joel@joelfernandes.org>
 <20220622225102.2112026-10-joel@joelfernandes.org>
 <Yrn9a5pOvhvL/eZj@pc638.lan>
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On Mon, Jun 27, 2022 at 08:56:43PM +0200, Uladzislau Rezki wrote:
> > As per the comments in include/linux/shrinker.h, .count_objects callback
> > should return the number of freeable items, but if there are no objects
> > to free, SHRINK_EMPTY should be returned. The only time 0 is returned
> > should be when we are unable to determine the number of objects, or the
> > cache should be skipped for another reason.
> > 
> > Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
> > ---
> >  kernel/rcu/tree.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
> > index 711679d10cbb..935788e8d2d7 100644
> > --- a/kernel/rcu/tree.c
> > +++ b/kernel/rcu/tree.c
> > @@ -3722,7 +3722,7 @@ kfree_rcu_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
> >  		atomic_set(&krcp->backoff_page_cache_fill, 1);
> >  	}
> >  
> > -	return count;
> > +	return count == 0 ? SHRINK_EMPTY : count;
> >  }
> >  
> >  static unsigned long
> > -- 
> > 2.37.0.rc0.104.g0611611a94-goog
> > 
> Looks good to me!
> 
> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>

Now that you mention it, this does look independent of the rest of
the series.  I have pulled it in with Uladzislau's Reviewed-by.

							Thanx, Paul