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=-7.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 ABF44C4363A for ; Mon, 26 Oct 2020 11:24:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 655192467C for ; Mon, 26 Oct 2020 11:24:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603711491; bh=MQ0/v4M+9um/4CqtMyy96DyV1IDJAihnw27n13nKzG4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=V2ifc+hIvpXa3B6NFOp+u33ir/rkjcRPPCDDmSy191ogpCKKWZ/YcGMlisqw+P/t8 HECZPj1OzSLbFJB4CGz3NS5a4K4+VUqg9iAkxF7RLysHh4vqoC45dZTqwbqqmh0NRE CFQzSf08kpb5xFiyS+j/JcpEssW1jpuorNNBh7Hs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1773746AbgJZLYu (ORCPT ); Mon, 26 Oct 2020 07:24:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:51506 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1770047AbgJZLYt (ORCPT ); Mon, 26 Oct 2020 07:24:49 -0400 Received: from localhost (unknown [176.177.109.29]) (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 044BB2464E; Mon, 26 Oct 2020 11:24:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603711488; bh=MQ0/v4M+9um/4CqtMyy96DyV1IDJAihnw27n13nKzG4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Brhj/SV313c9F6doqs8u0xyghwgifcl9lJ6EOnn1VpJKiSxmL1dFeiMYpkeZUX5AM kZS761u1cBN88PUvyyHdLYdmAlE7NWQ35ydz7+4qn5ZrvbMDOqUuCwR0n4nlNRLLSw XjvWGHbrIKfxKlcTNw7TmNpoUq+vpQKGPeaNpllg= Date: Mon, 26 Oct 2020 12:24:45 +0100 From: Frederic Weisbecker To: Joel Fernandes Cc: linux-kernel@vger.kernel.org, Josh Triplett , Lai Jiangshan , Marco Elver , Mathieu Desnoyers , "Paul E. McKenney" , rcu@vger.kernel.org, Steven Rostedt , "Uladzislau Rezki (Sony)" , fweisbec@gmail.com, neeraj.iitr10@gmail.com Subject: Re: [PATCH v8 2/6] rcu/segcblist: Add counters to segcblist datastructure Message-ID: <20201026112445.GC104441@lothringen> References: <20201021190813.3005054-1-joel@joelfernandes.org> <20201021190813.3005054-3-joel@joelfernandes.org> <20201026003212.GA104441@lothringen> <20201026054043.GA4192074@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201026054043.GA4192074@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 26, 2020 at 01:40:43AM -0400, Joel Fernandes wrote: > On Mon, Oct 26, 2020 at 01:32:12AM +0100, Frederic Weisbecker wrote: > > You seem to have forgotten the suggestion? > > > > rclp->len += rcu_segcblist_get_seglen(rsclp, i) > > I decided to keep it this way as I did not see how it could be better. > You mentioned you are Ok with either option so I left it as is. > > Thanks! Fair enough! > diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c > index 0f23d20d485a..79b7081143a7 100644 > --- a/kernel/rcu/srcutree.c > +++ b/kernel/rcu/srcutree.c > @@ -1160,6 +1160,7 @@ static void srcu_advance_state(struct srcu_struct *ssp) > */ > static void srcu_invoke_callbacks(struct work_struct *work) > { > + long len; > bool more; > struct rcu_cblist ready_cbs; > struct rcu_head *rhp; > @@ -1182,6 +1183,7 @@ static void srcu_invoke_callbacks(struct work_struct *work) > /* We are on the job! Extract and invoke ready callbacks. */ > sdp->srcu_cblist_invoking = true; > rcu_segcblist_extract_done_cbs(&sdp->srcu_cblist, &ready_cbs); > + len = ready_cbs.len; > spin_unlock_irq_rcu_node(sdp); > rhp = rcu_cblist_dequeue(&ready_cbs); > for (; rhp != NULL; rhp = rcu_cblist_dequeue(&ready_cbs)) { > @@ -1190,13 +1192,14 @@ static void srcu_invoke_callbacks(struct work_struct *work) > rhp->func(rhp); > local_bh_enable(); > } > + WARN_ON_ONCE(ready_cbs.len); > > /* > * Update counts, accelerate new callbacks, and if needed, > * schedule another round of callback invocation. > */ > spin_lock_irq_rcu_node(sdp); > - rcu_segcblist_insert_count(&sdp->srcu_cblist, &ready_cbs); > + rcu_segcblist_add_len(&sdp->srcu_cblist, -len); > (void)rcu_segcblist_accelerate(&sdp->srcu_cblist, > rcu_seq_snap(&ssp->srcu_gp_seq)); > sdp->srcu_cblist_invoking = false; Looks good! Thanks.