From patchwork Mon Jul 17 18:01:10 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Paul E. McKenney" X-Patchwork-Id: 13316148 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 CED66C001E0 for ; Mon, 17 Jul 2023 18:01:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231224AbjGQSBR (ORCPT ); Mon, 17 Jul 2023 14:01:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229603AbjGQSBP (ORCPT ); Mon, 17 Jul 2023 14:01:15 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B37FEE6C; Mon, 17 Jul 2023 11:01:14 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 5737F611D5; Mon, 17 Jul 2023 18:01:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8F604C433AD; Mon, 17 Jul 2023 18:01:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1689616872; bh=xfeG1xbltoTNTdzL3NqsELbTv/pa9FZB5bRq1zF+OuQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rYV63FMskzWxOynzItXA45uVGlpO3lupAQaIN8axaEuksbv960TRV2h2o3luJZuLB ylpn6KwLy/bs8SfIVknVOgKv8FSWLf6x2t3tGV90Et5z3obUQEhd0PB+5r8q8Q20gT 1U0pEZlKNIDmCcFQLNI1rc9YmIJxMlQlkau6jGm4gpBmx7EA9jmXCgspiaiH6ADrL/ jFtZTpIFTVLrjZMIEkbzCf4+E3Dwzr8yrCe2E2B2XMwJmf3H6bobh2FTgoEvXFpQBh U8F2eFEoBpz52Vc2H1mZahNNCwyysN3SBwdKXiXbv1PKzPNT2lusiHhW8zsUDj8+HT Txi7v1wuTyKrg== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id DF4D9CE0930; Mon, 17 Jul 2023 11:01:11 -0700 (PDT) From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, rostedt@goodmis.org, SeongJae Park , "Paul E . McKenney" Subject: [PATCH rcu 7/7] Docs/RCU/rculist_nulls: Fix text about atomic_set_release() Date: Mon, 17 Jul 2023 11:01:10 -0700 Message-Id: <20230717180110.1097362-7-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org From: SeongJae Park The document says we can avoid extra _release() in insert function when hlist_nulls is used, but that's not true[1]. Drop it. [1] https://lore.kernel.org/rcu/46440869-644a-4982-b790-b71b43976c66@paulmck-laptop/ Signed-off-by: SeongJae Park Signed-off-by: Paul E. McKenney --- Documentation/RCU/rculist_nulls.rst | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/Documentation/RCU/rculist_nulls.rst b/Documentation/RCU/rculist_nulls.rst index 1fb086066377..21e40fcc08de 100644 --- a/Documentation/RCU/rculist_nulls.rst +++ b/Documentation/RCU/rculist_nulls.rst @@ -140,8 +140,7 @@ very very fast (before the end of RCU grace period) Avoiding extra smp_rmb() ======================== -With hlist_nulls we can avoid extra smp_rmb() in lockless_lookup() -and extra _release() in insert function. +With hlist_nulls we can avoid extra smp_rmb() in lockless_lookup(). For example, if we choose to store the slot number as the 'nulls' end-of-list marker for each slot of the hash table, we can detect @@ -196,6 +195,9 @@ Note that using hlist_nulls means the type of 'obj_node' field of 2) Insert algorithm ------------------- +Same to the above one, but uses hlist_nulls_add_head_rcu() instead of +hlist_add_head_rcu(). + :: /*