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=unavailable 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 4DD09C433DF for ; Tue, 23 Jun 2020 00:23:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 236782076E for ; Tue, 23 Jun 2020 00:23:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592871800; bh=QdyVEtKG5bZE6YpANneYBroHwKvjQwPmzpo9lmFsayU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=S/QiCdi9WPwGpauYh7BeBVEoXBER1EmQPtstUpjr3ifaAUeSQSCCwpmPVWSvtHhTd ID9uYrypA6zg6gSWYBPUz5TmpPiQrKEFvwYmCIW9n3LuSZqbLnE3AeWEfxUd/06N4v aajMtmlKr1ZvGaKPoxtnrw3tu0gp1fNAWhLnGp8A= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731812AbgFWAXS (ORCPT ); Mon, 22 Jun 2020 20:23:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:48094 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731416AbgFWAVu (ORCPT ); Mon, 22 Jun 2020 20:21:50 -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 0EE77207F5; Tue, 23 Jun 2020 00:21:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592871710; bh=QdyVEtKG5bZE6YpANneYBroHwKvjQwPmzpo9lmFsayU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Jnifzw2SYUH+kxojlQPNqL1/nuv0hZ8a81YuhfNA/f8VVBuZjrYI7rfL87Queeu1c Vc8cI++4N/r9htg/+4l6oIa2n2ziADVCG2NqZYyli1q88YehSybLxtDwFlIReDg016 qB0H3tH8LhZWMNPQKriG+Dtt+b/5uLQhqfkJrueI= 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 tip/core/rcu 04/26] rcu: Add callbacks-invoked counters Date: Mon, 22 Jun 2020 17:21:25 -0700 Message-Id: <20200623002147.25750-4-paulmck@kernel.org> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20200623002128.GA25456@paulmck-ThinkPad-P72> References: <20200623002128.GA25456@paulmck-ThinkPad-P72> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Paul E. McKenney" This commit adds a count of the callbacks invoked to the per-CPU rcu_data structure. This count is printed by the show_rcu_gp_kthreads() that is invoked by rcutorture and the RCU CPU stall-warning code. It is also intended for use by drgn. Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 1 + kernel/rcu/tree.h | 1 + kernel/rcu/tree_stall.h | 3 +++ 3 files changed, 5 insertions(+) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 9caaeee..db17ffe 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2425,6 +2425,7 @@ static void rcu_do_batch(struct rcu_data *rdp) local_irq_save(flags); rcu_nocb_lock(rdp); count = -rcl.len; + rdp->n_cbs_invoked += count; trace_rcu_batch_end(rcu_state.name, count, !!rcl.head, need_resched(), is_idle_task(current), rcu_is_callbacks_kthread()); diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 43991a4..9c6f734 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -171,6 +171,7 @@ struct rcu_data { /* different grace periods. */ long qlen_last_fqs_check; /* qlen at last check for QS forcing */ + unsigned long n_cbs_invoked; /* # callbacks invoked since boot. */ unsigned long n_force_qs_snap; /* did other CPU force QS recently? */ long blimit; /* Upper limit on a processed batch */ diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h index 54a6dba..2768ce6 100644 --- a/kernel/rcu/tree_stall.h +++ b/kernel/rcu/tree_stall.h @@ -649,6 +649,7 @@ static void check_cpu_stall(struct rcu_data *rdp) */ void show_rcu_gp_kthreads(void) { + unsigned long cbs = 0; int cpu; unsigned long j; unsigned long ja; @@ -690,9 +691,11 @@ void show_rcu_gp_kthreads(void) } for_each_possible_cpu(cpu) { rdp = per_cpu_ptr(&rcu_data, cpu); + cbs += data_race(rdp->n_cbs_invoked); if (rcu_segcblist_is_offloaded(&rdp->cblist)) show_rcu_nocb_state(rdp); } + pr_info("RCU callbacks invoked since boot: %lu\n", cbs); show_rcu_tasks_gp_kthreads(); } EXPORT_SYMBOL_GPL(show_rcu_gp_kthreads); -- 2.9.5