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=-8.6 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,URIBL_BLOCKED,USER_AGENT_SANE_1 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 48996C433E1 for ; Fri, 19 Jun 2020 00:12:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2497320809 for ; Fri, 19 Jun 2020 00:12:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592525567; bh=rvKW+hIbAYj73rdDZn2HVrADx6qXHZ+iJvUCz4FW/R0=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:List-ID: From; b=BSze4m+HhvzK7DdxCW/nwJvjcAGBP0sjfn4B54mVxsQ+BGihw8vct9rFKL9pqiIxn VDHmeglOXKCN47c7tXfztD5Hqri2BrpIJiUZN/caYX7mEDBbiZS0Mk1s2Ei28QGS47 E00GxhkIY8D/YMWCCoM8+fnyKGiTcH4zVDwjBE8s= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728522AbgFSAMp (ORCPT ); Thu, 18 Jun 2020 20:12:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:42582 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726001AbgFSAMo (ORCPT ); Thu, 18 Jun 2020 20:12:44 -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-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6D303207D8; Fri, 19 Jun 2020 00:12:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592525564; bh=rvKW+hIbAYj73rdDZn2HVrADx6qXHZ+iJvUCz4FW/R0=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=TNBs43wjOzdALfUplj59a+kTlLH+H9Z379NZlhBs5fGCYaOiZWhWWYV/tHwe7Eeyl sH+VWs/bKXp/+TfQpxSv5YKqdi+UYPmhMhTcSHyDnqERGgzt9G0OU0hWb7xYL7O+UK GRNFWESs8XHNxUbvDXm/sUvPgwDetB56EntYkfJs= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id 5806B352264E; Thu, 18 Jun 2020 17:12:44 -0700 (PDT) Date: Thu, 18 Jun 2020 17:12:44 -0700 From: "Paul E. McKenney" To: Joel Fernandes Cc: linux-kernel@vger.kernel.org, Davidlohr Bueso , Ingo Molnar , Josh Triplett , Lai Jiangshan , Marco Elver , Mathieu Desnoyers , rcu@vger.kernel.org, Steven Rostedt , "Uladzislau Rezki (Sony)" Subject: Re: [PATCH 6/7] rcutorture: Add support to get the number of wakeups of main GP kthread Message-ID: <20200619001244.GG2723@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <20200618202955.4024-1-joel@joelfernandes.org> <20200618202955.4024-6-joel@joelfernandes.org> <20200618224058.GD2723@paulmck-ThinkPad-P72> <20200619000156.GD40119@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200619000156.GD40119@google.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 18, 2020 at 08:01:56PM -0400, Joel Fernandes wrote: > On Thu, Jun 18, 2020 at 03:40:58PM -0700, Paul E. McKenney wrote: > > On Thu, Jun 18, 2020 at 04:29:54PM -0400, Joel Fernandes (Google) wrote: > > > This is useful to check for any improvements or degradation related to > > > number of GP kthread wakeups during testing. > > > > > > Signed-off-by: Joel Fernandes (Google) > > > > This was a good way to collect the data for your testing, but > > we can expect rcutorture to only do so much. ;-) > > np, I will push this one into a git tag for the next time I need it ;) Sounds like a plan! Thanx, Paul > thanks, > > - Joel > > > > Thanx, Paul > > > > > --- > > > kernel/rcu/Kconfig.debug | 1 + > > > kernel/rcu/rcu.h | 2 ++ > > > kernel/rcu/rcutorture.c | 23 ++++++++++++++++++++++- > > > kernel/rcu/tree.c | 7 +++++++ > > > 4 files changed, 32 insertions(+), 1 deletion(-) > > > > > > diff --git a/kernel/rcu/Kconfig.debug b/kernel/rcu/Kconfig.debug > > > index 3cf6132a4bb9f..3323e3378af5a 100644 > > > --- a/kernel/rcu/Kconfig.debug > > > +++ b/kernel/rcu/Kconfig.debug > > > @@ -50,6 +50,7 @@ config RCU_TORTURE_TEST > > > select TASKS_RCU > > > select TASKS_RUDE_RCU > > > select TASKS_TRACE_RCU > > > + select SCHEDSTATS > > > default n > > > help > > > This option provides a kernel module that runs torture tests > > > diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h > > > index cf66a3ccd7573..7e867e81d9738 100644 > > > --- a/kernel/rcu/rcu.h > > > +++ b/kernel/rcu/rcu.h > > > @@ -511,6 +511,7 @@ srcu_batches_completed(struct srcu_struct *sp) { return 0; } > > > static inline void rcu_force_quiescent_state(void) { } > > > static inline void show_rcu_gp_kthreads(void) { } > > > static inline int rcu_get_gp_kthreads_prio(void) { return 0; } > > > +static inline struct task_struct *rcu_get_main_gp_kthread(void) { return 0; } > > > static inline void rcu_fwd_progress_check(unsigned long j) { } > > > #else /* #ifdef CONFIG_TINY_RCU */ > > > bool rcu_dynticks_zero_in_eqs(int cpu, int *vp); > > > @@ -519,6 +520,7 @@ unsigned long rcu_exp_batches_completed(void); > > > unsigned long srcu_batches_completed(struct srcu_struct *sp); > > > void show_rcu_gp_kthreads(void); > > > int rcu_get_gp_kthreads_prio(void); > > > +struct task_struct *rcu_get_main_gp_kthread(void); > > > void rcu_fwd_progress_check(unsigned long j); > > > void rcu_force_quiescent_state(void); > > > extern struct workqueue_struct *rcu_gp_wq; > > > diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c > > > index d0d265304d147..959a1f84d6904 100644 > > > --- a/kernel/rcu/rcutorture.c > > > +++ b/kernel/rcu/rcutorture.c > > > @@ -23,6 +23,7 @@ > > > #include > > > #include > > > #include > > > +#include > > > #include > > > #include > > > #include > > > @@ -460,9 +461,29 @@ static void rcu_sync_torture_init(void) > > > INIT_LIST_HEAD(&rcu_torture_removed); > > > } > > > > > > +unsigned long rcu_gp_nr_wakeups; > > > + > > > +static void rcu_flavor_init(void) > > > +{ > > > + rcu_sync_torture_init(); > > > + > > > + /* Make sure schedstat is enabled for GP thread wakeup count. */ > > > + force_schedstat_enabled(); > > > + rcu_gp_nr_wakeups = rcu_get_main_gp_kthread()->se.statistics.nr_wakeups; > > > +} > > > + > > > +static void rcu_flavor_cleanup(void) > > > +{ > > > + unsigned long now_nr = rcu_get_main_gp_kthread()->se.statistics.nr_wakeups; > > > + > > > + pr_alert("End-test: Cleanup: Total GP-kthread wakeups: %lu\n", > > > + now_nr - rcu_gp_nr_wakeups); > > > +} > > > + > > > static struct rcu_torture_ops rcu_ops = { > > > .ttype = RCU_FLAVOR, > > > - .init = rcu_sync_torture_init, > > > + .init = rcu_flavor_init, > > > + .cleanup = rcu_flavor_cleanup, > > > .readlock = rcu_torture_read_lock, > > > .read_delay = rcu_read_delay, > > > .readunlock = rcu_torture_read_unlock, > > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > > > index c3bae7a83d792..a3a175feb310a 100644 > > > --- a/kernel/rcu/tree.c > > > +++ b/kernel/rcu/tree.c > > > @@ -175,6 +175,13 @@ int rcu_get_gp_kthreads_prio(void) > > > } > > > EXPORT_SYMBOL_GPL(rcu_get_gp_kthreads_prio); > > > > > > +/* Retrieve RCU's main GP kthread task_struct */ > > > +struct task_struct *rcu_get_main_gp_kthread(void) > > > +{ > > > + return rcu_state.gp_kthread; > > > +} > > > +EXPORT_SYMBOL_GPL(rcu_get_main_gp_kthread); > > > + > > > /* > > > * Number of grace periods between delays, normalized by the duration of > > > * the delay. The longer the delay, the more the grace periods between > > > -- > > > 2.27.0.111.gc72c7da667-goog > > >