From patchwork Tue Jun 4 22:28:22 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Paul E. McKenney" X-Patchwork-Id: 13685936 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5BD4014B09F; Tue, 4 Jun 2024 22:28:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717540107; cv=none; b=B4I9spfXRraAUkBJIZvowqP2f6+kXlg/yU4N/5zNTcUSdFcL+AGWfRdWxP1Zpj2KbfUhFbruXBlfv8rUs+i15ZcyI0CdfPKzcq22Ld6CGJFxDcnfy26zBup1X7rqda6v0b9i7KrzzL3f1uYZ7HOhhS3sbUg0hGN8Xy2Nz6yY+g8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717540107; c=relaxed/simple; bh=L+vh4i7DG4WUW2lk/fFRObt2YALvvoHN6lDNkPzL758=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=YkqeMX5KC3uiGdn5EJsT2fju4lo7wmK56HH3rB2ZO2aPQEWOP8SRAQkSjc//xslB27YzMpIhI5rGMbXQlwkwgUhKIqidZjor6KJnZ/bMoWcot9k+4M7Ty/mvEcqhrW7YPRWs9BeF5Z2j6vm0fS/jvQjt75//5ayD2DlFWDMpcns= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pJYk/7+6; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="pJYk/7+6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0F0D3C3277B; Tue, 4 Jun 2024 22:28:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1717540107; bh=L+vh4i7DG4WUW2lk/fFRObt2YALvvoHN6lDNkPzL758=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pJYk/7+6d355+dU29WybwVSHg8f9bekAfAqsvjIYDVuC1jWpl4IAQbAI3psN6eoED Cp2KJ3EPKAohcZJBPkzt7PBE6n1dO6YIhJCUoqiaW7sijQzPxy80KHYYlcyjEM1Fr4 ciEprKKOCYUizwz/t/pIB6ifyws64MmaWEHSdoLZRHfyn4G2scMN/NZQLn7x6Iuiqn CLPF4soKeDzvWBsyRYDoTN97ojzT48rjEs4XRC3wL0UgAKOJmNfKsQ7GxqKJixeqNt 1f/EaNcS/4QAN4cvV+TEUFBuoRuOERcjSeEfqXpXVZ1muetQTw9XObGfAUer4jo4Z/ 1wAh4oZ/5YngA== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id C01B5CE3ED6; Tue, 4 Jun 2024 15:28:26 -0700 (PDT) From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, rostedt@goodmis.org, Frederic Weisbecker , "Paul E . McKenney" Subject: [PATCH rcu 1/4] rcu/nocb: Fix segcblist state machine comments about bypass Date: Tue, 4 Jun 2024 15:28:22 -0700 Message-Id: <20240604222825.2371133-1-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: rcu@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Frederic Weisbecker The parts explaining the bypass lifecycle in (de-)offloading are out of date and/or wrong. Bypass is simply enabled whenever SEGCBLIST_RCU_CORE flag is off. Fix the comments accordingly. Signed-off-by: Frederic Weisbecker Signed-off-by: Paul E. McKenney --- include/linux/rcu_segcblist.h | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/include/linux/rcu_segcblist.h b/include/linux/rcu_segcblist.h index 659d13a7ddaaa..1e5b4ef167caa 100644 --- a/include/linux/rcu_segcblist.h +++ b/include/linux/rcu_segcblist.h @@ -141,7 +141,7 @@ struct rcu_cblist { * | SEGCBLIST_KTHREAD_GP | * | | * | CB/GP kthreads handle callbacks holding nocb_lock, local rcu_core() | - * | handles callbacks concurrently. Bypass enqueue is enabled. | + * | handles callbacks concurrently. Bypass enqueue is disabled. | * | Invoke RCU core so we make sure not to preempt it in the middle with | * | leaving some urgent work unattended within a jiffy. | * ---------------------------------------------------------------------------- @@ -154,8 +154,7 @@ struct rcu_cblist { * | SEGCBLIST_KTHREAD_GP | * | | * | CB/GP kthreads and local rcu_core() handle callbacks concurrently | - * | holding nocb_lock. Wake up CB and GP kthreads if necessary. Disable | - * | bypass enqueue. | + * | holding nocb_lock. Wake up CB and GP kthreads if necessary. | * ---------------------------------------------------------------------------- * | * v @@ -185,7 +184,7 @@ struct rcu_cblist { * | | * | Callbacks processed by rcu_core() from softirqs or local | * | rcuc kthread, while holding nocb_lock. Forbid nocb_timer to be armed. | - * | Flush pending nocb_timer. Flush nocb bypass callbacks. | + * | Flush pending nocb_timer. | * ---------------------------------------------------------------------------- * | * v