From patchwork Tue Nov 22 01:04:10 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: 13051757 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 91633C43219 for ; Tue, 22 Nov 2022 01:04:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232048AbiKVBEd (ORCPT ); Mon, 21 Nov 2022 20:04:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44780 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231970AbiKVBE0 (ORCPT ); Mon, 21 Nov 2022 20:04:26 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9D8F615804; Mon, 21 Nov 2022 17:04:25 -0800 (PST) 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 36A14B818E6; Tue, 22 Nov 2022 01:04:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C09FDC433C1; Tue, 22 Nov 2022 01:04:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1669079062; bh=U3+4ieL/lmCXWeRZRiLB8u0S5rhXMcyArw0nT7Mm3tc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=msgDCNIf5wTHEMiqK1Oby1Kv9Mul5DyWDroLunYs3RPd6Q4u0lEwQZKrTci5eEb8g D3NdwkLIwRwI6jk7mIMqe8ZH/iMBjQIKoUAxKYnVJxFFjzd/gWwAgFKUW+BQiIcMaQ fMA6510Y+gWdcIfhQK17+Bh0yKljOgZ4RhZXP/BL/VD8U3Jr2whVpiM6gHRbs1wXoy z2JnJ8viIApXCPsicuQ8+9JM+QwsBoDnbkMs+M0qlwfhT8kx1/XcJFyAp8uKEcLGuL yWRCMfiBG4xzWEkPbjr8rXkELND3r3n7zETP0DjxmeBfT34P2t0T6klB+V7PgdumKq mNb4lVjLFgKCA== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 799CB5C116D; Mon, 21 Nov 2022 17:04:22 -0800 (PST) From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, rostedt@goodmis.org, "Joel Fernandes (Google)" , "Paul E . McKenney" Subject: [PATCH v2 rcu 05/16] rcu: Refactor code a bit in rcu_nocb_do_flush_bypass() Date: Mon, 21 Nov 2022 17:04:10 -0800 Message-Id: <20221122010421.3799681-5-paulmck@kernel.org> X-Mailer: git-send-email 2.31.1.189.g2e36527f23 In-Reply-To: <20221122010408.GA3799268@paulmck-ThinkPad-P17-Gen-1> References: <20221122010408.GA3799268@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 Reviewed-by: Frederic Weisbecker --- 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);