From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0B58CC4363A for ; Fri, 23 Oct 2020 14:47:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B4C2A20EDD for ; Fri, 23 Oct 2020 14:47:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603464468; bh=bGi/rnp5UbyotlPlQTWgF7VznJ464GbGJ801ntzuXz8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=wcOK9Rs40lvfx6lnfJ/eFFXR+Qrx7RuBTvx2fLfM69roHZB0NHHAXh5eqw2APZPlh /pK8KIDswkVBl/Uhrt/m1U/ttoNAefZ2hNHWHF2QyRUhHOMoLSeYD3gAFkLrc5WsKw 3LKDnBGbV1NFQjnlb5St3cCeh0JkXrpGK8j8NDjs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750799AbgJWOrr (ORCPT ); Fri, 23 Oct 2020 10:47:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:33436 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750761AbgJWOrY (ORCPT ); Fri, 23 Oct 2020 10:47:24 -0400 Received: from localhost.localdomain (unknown [176.167.163.208]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0EB2C20853; Fri, 23 Oct 2020 14:47:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603464444; bh=bGi/rnp5UbyotlPlQTWgF7VznJ464GbGJ801ntzuXz8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kaT5m/4lc2DiSjujbQwaZWHgsBAyS5yyy1b2E6/CSuz6XCoYP5gGQDHYUbTCNjHnc 9v7U7Yy4smraH8nM++2SOqIVPwxi5MC7ccl+xXboENpTIADBEqIJzHTVbXeliMOm78 GjYtfI494XbC/+GLUMH9xJcb2GQbeGatmy5/f2QA= From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Steven Rostedt , Mathieu Desnoyers , "Paul E . McKenney" , Lai Jiangshan , Neeraj Upadhyay , Joel Fernandes , Josh Triplett Subject: [PATCH 11/16] rcu: Set SEGCBLIST_SOFTIRQ_ONLY at the very last stage of de-offloading Date: Fri, 23 Oct 2020 16:46:44 +0200 Message-Id: <20201023144649.53046-12-frederic@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201023144649.53046-1-frederic@kernel.org> References: <20201023144649.53046-1-frederic@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Set SEGCBLIST_SOFTIRQ_ONLY once everything is settled. After that, the callbacks are handled locklessly and locally. Inspired-by: Paul E. McKenney Signed-off-by: Frederic Weisbecker Cc: Paul E. McKenney Cc: Josh Triplett Cc: Steven Rostedt Cc: Mathieu Desnoyers Cc: Lai Jiangshan Cc: Joel Fernandes Cc: Neeraj Upadhyay --- kernel/rcu/tree_plugin.h | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 49bd42995ae7..2f083beab9d9 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -2353,7 +2353,14 @@ static int __rcu_nocb_rdp_deoffload(struct rcu_data *rdp) * enqueued on bypass. */ rcu_nocb_flush_bypass(rdp, NULL, jiffies); - rcu_nocb_unlock_irqrestore(rdp, flags); + rcu_segcblist_set_flags(cblist, SEGCBLIST_SOFTIRQ_ONLY); + /* + * With SEGCBLIST_SOFTIRQ_ONLY, we can't use + * rcu_nocb_unlock_irqrestore() anymore. Theoretically we + * could set SEGCBLIST_SOFTIRQ_ONLY with cb unlocked and IRQs + * disabled now, but let's be paranoid. + */ + raw_spin_unlock_irqrestore(&rdp->nocb_lock, flags); return ret; } -- 2.25.1