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[94.245.46.49]) by smtp.gmail.com with ESMTPSA id q15sm96025lfc.44.2020.06.04.11.39.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 04 Jun 2020 11:39:30 -0700 (PDT) From: Uladzislau Rezki X-Google-Original-From: Uladzislau Rezki Date: Thu, 4 Jun 2020 20:39:27 +0200 To: "Paul E. McKenney" Cc: Uladzislau Rezki , Peter Enderborg , Josh Triplett , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , Joel Fernandes , rcu@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] rcu: Stop shrinker loop Message-ID: <20200604183927.GA26933@pc636> References: <20200604102320.15914-1-peter.enderborg@sony.com> <20200604134255.GA24897@pc636> <20200604163100.GB29598@paulmck-ThinkPad-P72> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200604163100.GB29598@paulmck-ThinkPad-P72> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Thu, Jun 04, 2020 at 03:42:55PM +0200, Uladzislau Rezki wrote: > > On Thu, Jun 04, 2020 at 12:23:20PM +0200, Peter Enderborg wrote: > > > The count and scan can be separated in time. It is a fair chance > > > that all work is already done when the scan starts. It > > > then might retry. This is can be avoided with returning SHRINK_STOP. > > > > > > Signed-off-by: Peter Enderborg > > > --- > > > 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 c716eadc7617..8b36c6b2887d 100644 > > > --- a/kernel/rcu/tree.c > > > +++ b/kernel/rcu/tree.c > > > @@ -3310,7 +3310,7 @@ kfree_rcu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) > > > break; > > > } > > > > > > - return freed; > > > + return freed == 0 ? SHRINK_STOP : freed; > > > } > > > > > The loop will be stopped anyway sooner or later, but sooner is better :) > > To me that change makes sense. > > > > Reviewed-by: Uladzislau Rezki (Sony) > > Queued, thank you both! > Thank you, Paul! -- Vlad Rezki