From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C3218C433E0 for ; Thu, 4 Jun 2020 16:31:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A2868206E6 for ; Thu, 4 Jun 2020 16:31:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591288261; bh=p22Qks7bzkvMwOfKr4OS5tjK01cXYo3wKjWBTk6+0r4=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:List-ID: From; b=pf0ko/erw0r/i0rQsT0Cqshw8S3gfnXuHGlPmiC4GivX2k1bDJQjubyB2X/gBdO4Y myV6tJrda1LARn/UVfUfVTH7iF/U/S3wq92xprwb0v94DRkDUpvgV5KpAs52Wy2cVs O5I5yetq7ziD2+dc9Qihl7VN5xwORpqGjP+AKPD4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729742AbgFDQbA (ORCPT ); Thu, 4 Jun 2020 12:31:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:48418 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729115AbgFDQbA (ORCPT ); Thu, 4 Jun 2020 12:31:00 -0400 Received: from paulmck-ThinkPad-P72.home (50-39-105-78.bvtn.or.frontiernet.net [50.39.105.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 260AA206DC; Thu, 4 Jun 2020 16:31:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591288260; bh=p22Qks7bzkvMwOfKr4OS5tjK01cXYo3wKjWBTk6+0r4=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=uV9GQ7XZ003JbvFHFVSz63OBBEqFTRLALl6oVWQ4yfQ9dpq11k7ya0hsCfTXFRHLa TFNkkZQI46i3s3lfPSwRZUD8h19yU6TOb/1ACMlfvrKGQ4yK28x0Xmv0ktc6JPfmys nDkq8YHA/Yi15oa7Wa3949Ccr6aUbWhS6FGGa6DY= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id 0B6F835228BC; Thu, 4 Jun 2020 09:31:00 -0700 (PDT) Date: Thu, 4 Jun 2020 09:31:00 -0700 From: "Paul E. McKenney" To: Uladzislau Rezki Cc: 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: <20200604163100.GB29598@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <20200604102320.15914-1-peter.enderborg@sony.com> <20200604134255.GA24897@pc636> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200604134255.GA24897@pc636> User-Agent: Mutt/1.9.4 (2018-02-28) 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! Thanx, Paul