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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 5C1E1C2BB85 for ; Wed, 15 Apr 2020 18:20:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 337A120784 for ; Wed, 15 Apr 2020 18:20:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586974842; bh=QIr3q6WJeHBwvcnpzSb8RI7xT1nOvA436IPTiIBNnsk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=165AJJQrITBDecDe+LzXm5TaH98pmqGQ+4hvS7YeGEQT8hG7Nxfwi4lhJFnURGr4z RGbuxwut/ArQT4ph4T8kq+Nji+27wNfc+g8JeVXKv9kJLDsjkEo4rbPVMUAf+C7plm +DHPNw5xmxrhEiKRu6GgK65obuPQJWWPPh11MuhI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2441379AbgDOSUk (ORCPT ); Wed, 15 Apr 2020 14:20:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:37916 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2441397AbgDOSTz (ORCPT ); Wed, 15 Apr 2020 14:19:55 -0400 Received: from paulmck-ThinkPad-P72.home (50-39-105-78.bvtn.or.frontiernet.net [50.39.105.78]) (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 E534321D93; Wed, 15 Apr 2020 18:19:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586974795; bh=QIr3q6WJeHBwvcnpzSb8RI7xT1nOvA436IPTiIBNnsk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GW2zFVczztjN4bJY29efVzzIVHx41bxIYv3It+siKOgBy6eWZGZsrfaxYP3digHN+ 8K3X4+q+5D+5yJU9N4UYCon/17El19C4wUEbWvY12dLjMN/iPsmqtDRukSJkBnKYBE /+v07pfADZKi63oUrq3w9VAzpGitfke/6cALb0VU= From: paulmck@kernel.org To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com, mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org, "Paul E. McKenney" Subject: [PATCH v4 tip/core/rcu 33/38] rcu-tasks: Add count for idle tasks on offline CPUs Date: Wed, 15 Apr 2020 11:19:36 -0700 Message-Id: <20200415181941.11653-33-paulmck@kernel.org> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20200415181856.GA11037@paulmck-ThinkPad-P72> References: <20200415181856.GA11037@paulmck-ThinkPad-P72> Sender: rcu-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org From: "Paul E. McKenney" This commit adds a counter for the number of times the quiescent state was an idle task associated with an offline CPU, and prints this count at the end of rcutorture runs and at stall time. Signed-off-by: Paul E. McKenney --- kernel/rcu/tasks.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h index b51f19a..43cac4b 100644 --- a/kernel/rcu/tasks.h +++ b/kernel/rcu/tasks.h @@ -729,6 +729,7 @@ static DEFINE_PER_CPU(bool, trc_ipi_to_cpu); // heavyweight readers executing explicit memory barriers. unsigned long n_heavy_reader_attempts; unsigned long n_heavy_reader_updates; +unsigned long n_heavy_reader_ofl_updates; void call_rcu_tasks_trace(struct rcu_head *rhp, rcu_callback_t func); DEFINE_RCU_TASKS(rcu_tasks_trace, rcu_tasks_wait_gp, call_rcu_tasks_trace, @@ -840,6 +841,8 @@ static bool trc_inspect_reader(struct task_struct *t, void *arg) !rcu_dynticks_zero_in_eqs(cpu, &t->trc_reader_nesting)) return false; // No quiescent state, do it the hard way. n_heavy_reader_updates++; + if (ofl) + n_heavy_reader_ofl_updates++; in_qs = true; } else { in_qs = likely(!t->trc_reader_nesting); @@ -1152,7 +1155,8 @@ static void show_rcu_tasks_trace_gp_kthread(void) { char buf[64]; - sprintf(buf, "N%d h:%lu/%lu", atomic_read(&trc_n_readers_need_end), + sprintf(buf, "N%d h:%lu/%lu/%lu", atomic_read(&trc_n_readers_need_end), + data_race(n_heavy_reader_ofl_updates), data_race(n_heavy_reader_updates), data_race(n_heavy_reader_attempts)); show_rcu_tasks_generic_gp_kthread(&rcu_tasks_trace, buf); -- 2.9.5