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=-20.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS 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 2CA45C433E0 for ; Fri, 12 Feb 2021 13:03:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F23B764E3D for ; Fri, 12 Feb 2021 13:03:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232079AbhBLNDF (ORCPT ); Fri, 12 Feb 2021 08:03:05 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:45294 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231391AbhBLMlL (ORCPT ); Fri, 12 Feb 2021 07:41:11 -0500 Date: Fri, 12 Feb 2021 12:37:24 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1613133444; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=0uWQouaHdTNr4Rz4dnXIsHn8uSYGN60tJaRAyuK/TNs=; b=ksdgNN9GUgBavjCmfrfeSbX0SUPjl6BP4p+gMx+nR5Avl2NF0+mnUVUSjYDdQSsXa9DqsR V0tkXaLSbiYM+/B7CJyNvk8RFzuMKs6s5iXz1bn58j9dxRyg97PNQlyA2oP4gDLn3F83ck dwUzoYF0xcHKs2ltxTK9qe/kauKpX5OXL91Afp/PkhjZA/XDKKFom03OhyiBAqSaKaANT1 nVam9a9i8ZOYg+ARCASpKqa9qY1B5dA5cc/w14d70e0oe8SqW5lwyR8Q0Il9C26iSmdj33 7dLW5+EsAZY7JprgMHyrNHER0aeySlWVuPvfI8yUCyjSY/sJTe7IeO5HLYXZYw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1613133444; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=0uWQouaHdTNr4Rz4dnXIsHn8uSYGN60tJaRAyuK/TNs=; b=voYFe9huZm8QgWWwePHKnYf2owxtrlp5in3xhvffp1/SvVHvd+BRHGuWa5fdp8bRoUD6Wv /HW5ggpNMySCAKCA== From: "tip-bot2 for Paul E. McKenney" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: core/rcu] rcu: Add lockdep_assert_irqs_disabled() to rcu_sched_clock_irq() and callees Cc: "Paul E. McKenney" , x86@kernel.org, linux-kernel@vger.kernel.org MIME-Version: 1.0 Message-ID: <161313344404.23325.1167006462840978391.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the core/rcu branch of tip: Commit-ID: a649d25dcc671a33b9cc3176411920fdc5fbd98e Gitweb: https://git.kernel.org/tip/a649d25dcc671a33b9cc3176411920fdc5fbd98e Author: Paul E. McKenney AuthorDate: Thu, 19 Nov 2020 10:13:06 -08:00 Committer: Paul E. McKenney CommitterDate: Mon, 04 Jan 2021 15:54:49 -08:00 rcu: Add lockdep_assert_irqs_disabled() to rcu_sched_clock_irq() and callees This commit adds a number of lockdep_assert_irqs_disabled() calls to rcu_sched_clock_irq() and a number of the functions that it calls. The point of this is to help track down a situation where lockdep appears to be insisting that interrupts are enabled within these functions, which should only ever be invoked from the scheduling-clock interrupt handler. Link: https://lore.kernel.org/lkml/20201111133813.GA81547@elver.google.com/ Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 4 ++++ kernel/rcu/tree_plugin.h | 1 + kernel/rcu/tree_stall.h | 8 ++++++++ 3 files changed, 13 insertions(+) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index bd04b09..f70634f 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2553,6 +2553,7 @@ static void rcu_do_batch(struct rcu_data *rdp) void rcu_sched_clock_irq(int user) { trace_rcu_utilization(TPS("Start scheduler-tick")); + lockdep_assert_irqs_disabled(); raw_cpu_inc(rcu_data.ticks_this_gp); /* The load-acquire pairs with the store-release setting to true. */ if (smp_load_acquire(this_cpu_ptr(&rcu_data.rcu_urgent_qs))) { @@ -2566,6 +2567,7 @@ void rcu_sched_clock_irq(int user) rcu_flavor_sched_clock_irq(user); if (rcu_pending(user)) invoke_rcu_core(); + lockdep_assert_irqs_disabled(); trace_rcu_utilization(TPS("End scheduler-tick")); } @@ -3690,6 +3692,8 @@ static int rcu_pending(int user) struct rcu_data *rdp = this_cpu_ptr(&rcu_data); struct rcu_node *rnp = rdp->mynode; + lockdep_assert_irqs_disabled(); + /* Check for CPU stalls, if enabled. */ check_cpu_stall(rdp); diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index fd8a52e..cb76e70 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -682,6 +682,7 @@ static void rcu_flavor_sched_clock_irq(int user) { struct task_struct *t = current; + lockdep_assert_irqs_disabled(); if (user || rcu_is_cpu_rrupt_from_idle()) { rcu_note_voluntary_context_switch(current); } diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h index ca21d28..4024dcc 100644 --- a/kernel/rcu/tree_stall.h +++ b/kernel/rcu/tree_stall.h @@ -260,6 +260,7 @@ static int rcu_print_task_stall(struct rcu_node *rnp, unsigned long flags) struct task_struct *t; struct task_struct *ts[8]; + lockdep_assert_irqs_disabled(); if (!rcu_preempt_blocked_readers_cgp(rnp)) return 0; pr_err("\tTasks blocked on level-%d rcu_node (CPUs %d-%d):", @@ -284,6 +285,7 @@ static int rcu_print_task_stall(struct rcu_node *rnp, unsigned long flags) ".q"[rscr.rs.b.need_qs], ".e"[rscr.rs.b.exp_hint], ".l"[rscr.on_blkd_list]); + lockdep_assert_irqs_disabled(); put_task_struct(t); ndetected++; } @@ -472,6 +474,8 @@ static void print_other_cpu_stall(unsigned long gp_seq, unsigned long gps) struct rcu_node *rnp; long totqlen = 0; + lockdep_assert_irqs_disabled(); + /* Kick and suppress, if so configured. */ rcu_stall_kick_kthreads(); if (rcu_stall_is_suppressed()) @@ -493,6 +497,7 @@ static void print_other_cpu_stall(unsigned long gp_seq, unsigned long gps) } } ndetected += rcu_print_task_stall(rnp, flags); // Releases rnp->lock. + lockdep_assert_irqs_disabled(); } for_each_possible_cpu(cpu) @@ -538,6 +543,8 @@ static void print_cpu_stall(unsigned long gps) struct rcu_node *rnp = rcu_get_root(); long totqlen = 0; + lockdep_assert_irqs_disabled(); + /* Kick and suppress, if so configured. */ rcu_stall_kick_kthreads(); if (rcu_stall_is_suppressed()) @@ -592,6 +599,7 @@ static void check_cpu_stall(struct rcu_data *rdp) unsigned long js; struct rcu_node *rnp; + lockdep_assert_irqs_disabled(); if ((rcu_stall_is_suppressed() && !READ_ONCE(rcu_kick_kthreads)) || !rcu_gp_in_progress()) return;