From patchwork Wed Aug 31 18:06:21 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: 12961195 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 CAF1EECAAD1 for ; Wed, 31 Aug 2022 18:06:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232176AbiHaSGj (ORCPT ); Wed, 31 Aug 2022 14:06:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40754 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232141AbiHaSGe (ORCPT ); Wed, 31 Aug 2022 14:06:34 -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 813E8E3983; Wed, 31 Aug 2022 11:06:30 -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 A0E3AB82273; Wed, 31 Aug 2022 18:06:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 48530C433D6; Wed, 31 Aug 2022 18:06:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1661969187; bh=j7Vt+WhUPkmdxBzO+D24Yf2KD8/sQg3Uw1rN8AJx8XI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DwI9B3r+CnqTXMKM5ybBKM/kKxZC0BwiGC+MLk85ckyYsA0g/s+tmuhe1SnCxrpBR hV2j2FGREwfxQ8ySaPlnI8p9/uZHyEZgcCAXUZ3goC3ifogzdf09qKf6claChLd84S ghDrcrHaOxX8iDjjfhJkTvxsbJRx8fExndJ2cL8CD2neyLxxHorM0VCGl4k6G+KNMX peLDis2g5qr5G/lsXoHmOYvCgIeEZAT7ukw1D6P97jR1s0i0rt3K0oWcIfHsZ6CW1O lc+BUXcJs883AbhVb07GNpibDI5K7FRJEh/YScwaBt8pVP6XAdIk21oyjAN0XxJ0ZU CsoVnuiASbO6Q== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 034755C02A9; Wed, 31 Aug 2022 11:06:27 -0700 (PDT) From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com, rostedt@goodmis.org, "Paul E. McKenney" Subject: [PATCH rcu 3/7] doc: Use rcu_barrier() to rate-limit RCU callbacks Date: Wed, 31 Aug 2022 11:06:21 -0700 Message-Id: <20220831180625.2692892-3-paulmck@kernel.org> X-Mailer: git-send-email 2.31.1.189.g2e36527f23 In-Reply-To: <20220831180617.GA2692480@paulmck-ThinkPad-P17-Gen-1> References: <20220831180617.GA2692480@paulmck-ThinkPad-P17-Gen-1> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org The checklist.rst document advises periodic synchronize_rcu() invocations to prevent callback flooding. However, rcu_barrier() is often a better choice. This commit therefore adds words to this effect. Signed-off-by: Paul E. McKenney --- Documentation/RCU/checklist.rst | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/Documentation/RCU/checklist.rst b/Documentation/RCU/checklist.rst index 2db206fc3465f..178ca7547b987 100644 --- a/Documentation/RCU/checklist.rst +++ b/Documentation/RCU/checklist.rst @@ -305,7 +305,8 @@ over a rather long period of time, but improvements are always welcome! the machine. d. Periodically invoke synchronize_rcu(), permitting a limited - number of updates per grace period. + number of updates per grace period. Better yet, periodically + invoke rcu_barrier() to wait for all outstanding callbacks. The same cautions apply to call_srcu() and kfree_rcu().