From patchwork Wed Oct 19 22:51:35 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Paul E. McKenney" X-Patchwork-Id: 13012458 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5EE7EC4332F for ; Wed, 19 Oct 2022 22:52:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229904AbiJSWwA (ORCPT ); Wed, 19 Oct 2022 18:52:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51164 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230371AbiJSWvx (ORCPT ); Wed, 19 Oct 2022 18:51:53 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E6B2518F26F; Wed, 19 Oct 2022 15:51:49 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 30935B8261B; Wed, 19 Oct 2022 22:51:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BEFD7C4347C; Wed, 19 Oct 2022 22:51:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666219906; bh=U3+4ieL/lmCXWeRZRiLB8u0S5rhXMcyArw0nT7Mm3tc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aXyfqiSSPcD8uihbcQQsOhuv8uB2FhPe5BW3m7mBtg8Njne6MornkUtJW2OjiMWKj LqyXFvjZw8GPKhvNIvuocWTS4z0aImtcd6CzrM7J8bbL5Nwvl8Ojd1et9HFJi28We1 4KXX7qt8Jwqbh29nHQ05z7eTsRLzKuaimihSOg5xwuBrlQgDG0L+etBFrn9oKA4JSR XVEDKhm27IADRU/VtEYXAf6lEKoCuHsjT/Qb+uKNV1g+C6hpDXxBj1AYSbac/GY57Q EXpWTeuMcgE2V3p8EoGJrnBshgmOPfg5kAaUEP2AJlZRtCMq+dl93qtdMDY9UvJV9b F/ePiJKHoEl8Q== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 7EC325C0A04; Wed, 19 Oct 2022 15:51:46 -0700 (PDT) From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com, rostedt@goodmis.org, "Joel Fernandes (Google)" , "Paul E . McKenney" Subject: [PATCH rcu 05/14] rcu: Refactor code a bit in rcu_nocb_do_flush_bypass() Date: Wed, 19 Oct 2022 15:51:35 -0700 Message-Id: <20221019225144.2500095-5-paulmck@kernel.org> X-Mailer: git-send-email 2.31.1.189.g2e36527f23 In-Reply-To: <20221019225138.GA2499943@paulmck-ThinkPad-P17-Gen-1> References: <20221019225138.GA2499943@paulmck-ThinkPad-P17-Gen-1> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org From: "Joel Fernandes (Google)" This consolidates the code a bit and makes it cleaner. Functionally it is the same. Reported-by: Paul E. McKenney Signed-off-by: Joel Fernandes (Google) Signed-off-by: Paul E. McKenney --- kernel/rcu/tree_nocb.h | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h index d6e4c076b0515..213daf81c057f 100644 --- a/kernel/rcu/tree_nocb.h +++ b/kernel/rcu/tree_nocb.h @@ -327,10 +327,11 @@ static void wake_nocb_gp_defer(struct rcu_data *rdp, int waketype, * * Note that this function always returns true if rhp is NULL. */ -static bool rcu_nocb_do_flush_bypass(struct rcu_data *rdp, struct rcu_head *rhp, +static bool rcu_nocb_do_flush_bypass(struct rcu_data *rdp, struct rcu_head *rhp_in, unsigned long j, bool lazy) { struct rcu_cblist rcl; + struct rcu_head *rhp = rhp_in; WARN_ON_ONCE(!rcu_rdp_is_offloaded(rdp)); rcu_lockdep_assert_cblist_protected(rdp); @@ -345,16 +346,16 @@ static bool rcu_nocb_do_flush_bypass(struct rcu_data *rdp, struct rcu_head *rhp, /* * If the new CB requested was a lazy one, queue it onto the main - * ->cblist so we can take advantage of a sooner grade period. + * ->cblist so that we can take advantage of the grace-period that will + * happen regardless. But queue it onto the bypass list first so that + * the lazy CB is ordered with the existing CBs in the bypass list. */ if (lazy && rhp) { - rcu_cblist_flush_enqueue(&rcl, &rdp->nocb_bypass, NULL); - rcu_cblist_enqueue(&rcl, rhp); - WRITE_ONCE(rdp->lazy_len, 0); - } else { - rcu_cblist_flush_enqueue(&rcl, &rdp->nocb_bypass, rhp); - WRITE_ONCE(rdp->lazy_len, 0); + rcu_cblist_enqueue(&rdp->nocb_bypass, rhp); + rhp = NULL; } + rcu_cblist_flush_enqueue(&rcl, &rdp->nocb_bypass, rhp); + WRITE_ONCE(rdp->lazy_len, 0); rcu_segcblist_insert_pend_cbs(&rdp->cblist, &rcl); WRITE_ONCE(rdp->nocb_bypass_first, j);