From: Frederic Weisbecker <frederic@kernel.org>
To: "Paul E. McKenney" <paulmck@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Boqun Feng <boqun.feng@gmail.com>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Neeraj Upadhyay <neeraju@codeaurora.org>,
Josh Triplett <josh@joshtriplett.org>,
Stable <stable@vger.kernel.org>,
Joel Fernandes <joel@joelfernandes.org>
Subject: Re: [PATCH 12/13] rcu/nocb: Prepare for finegrained deferred wakeup
Date: Tue, 16 Mar 2021 12:45:26 +0100 [thread overview]
Message-ID: <20210316114526.GA639918@lothringen> (raw)
In-Reply-To: <20210316030239.GA13675@paulmck-ThinkPad-P72>
On Mon, Mar 15, 2021 at 08:02:39PM -0700, Paul E. McKenney wrote:
> On Tue, Feb 23, 2021 at 01:10:10AM +0100, Frederic Weisbecker wrote:
> > Provide a way to tune the deferred wakeup level we want to perform from
> > a safe wakeup point. Currently those sites are:
> >
> > * nocb_timer
> > * user/idle/guest entry
> > * CPU down
> > * softirq/rcuc
> >
> > All of these sites perform the wake up for both RCU_NOCB_WAKE and
> > RCU_NOCB_WAKE_FORCE.
> >
> > In order to merge nocb_timer and nocb_bypass_timer together, we plan to
> > add a new RCU_NOCB_WAKE_BYPASS that really want to be deferred until
> > a timer fires so that we don't wake up the NOCB-gp kthread too early.
> >
> > To prepare for that, integrate a wake up level/limit that a callsite is
> > deemed to perform.
>
> This appears to need the following in order to build for non-NOCB
> configurations. I will fold it in and am retesting.
>
> Thanx, Paul
>
> ------------------------------------------------------------------------
>
> commit 55f59dd75a11455cf558fd387fbf9011017dcc8a
> Author: Paul E. McKenney <paulmck@kernel.org>
> Date: Mon Mar 15 20:00:34 2021 -0700
>
> squash! rcu/nocb: Prepare for fine-grained deferred wakeup
>
> [ paulmck: Fix non-NOCB rcu_nocb_need_deferred_wakeup() definition. ]
> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
>
> diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
> index 0cc7f68..dfb048e 100644
> --- a/kernel/rcu/tree_plugin.h
> +++ b/kernel/rcu/tree_plugin.h
> @@ -2926,7 +2926,7 @@ static void __init rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp)
> {
> }
>
> -static int rcu_nocb_need_deferred_wakeup(struct rcu_data *rdp)
> +static int rcu_nocb_need_deferred_wakeup(struct rcu_data *rdp, int level)
> {
> return false;
> }
Oops thanks, I missed that.
next prev parent reply other threads:[~2021-03-16 11:46 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-23 0:09 [PATCH 00/13] rcu/nocb updates v2 Frederic Weisbecker
2021-02-23 0:09 ` [PATCH 01/13] rcu/nocb: Fix potential missed nocb_timer rearm Frederic Weisbecker
2021-02-24 18:37 ` Paul E. McKenney
2021-02-24 22:06 ` Frederic Weisbecker
2021-02-25 0:14 ` Paul E. McKenney
2021-02-25 0:48 ` Frederic Weisbecker
2021-02-25 1:07 ` Paul E. McKenney
2021-03-02 1:48 ` Paul E. McKenney
2021-03-02 12:34 ` Frederic Weisbecker
2021-03-02 18:17 ` Paul E. McKenney
2021-03-03 1:35 ` Frederic Weisbecker
2021-03-03 2:06 ` Paul E. McKenney
2021-03-03 2:17 ` Frederic Weisbecker
2021-03-03 11:15 ` Neeraj Upadhyay
2021-02-23 0:10 ` [PATCH 02/13] rcu/nocb: Disable bypass when CPU isn't completely offloaded Frederic Weisbecker
2021-02-23 0:10 ` [PATCH 03/13] rcu/nocb: Remove stale comment above rcu_segcblist_offload() Frederic Weisbecker
2021-02-23 0:10 ` [PATCH 04/13] rcu/nocb: Move trace_rcu_nocb_wake() calls outside nocb_lock when possible Frederic Weisbecker
2021-02-23 0:10 ` [PATCH 05/13] rcu/nocb: Merge nocb_timer to the rdp leader Frederic Weisbecker
2021-03-03 1:15 ` [PATCH 05/13] rcu/nocb: Use the rcuog CPU's ->nocb_timer Paul E. McKenney
2021-03-10 22:05 ` Frederic Weisbecker
2021-03-16 0:02 ` Paul E. McKenney
2021-02-23 0:10 ` [PATCH 06/13] timer: Revert "timer: Add timer_curr_running()" Frederic Weisbecker
2021-02-23 0:10 ` [PATCH 07/13] rcu/nocb: Directly call __wake_nocb_gp() from bypass timer Frederic Weisbecker
2021-02-23 0:10 ` [PATCH 08/13] rcu/nocb: Allow de-offloading rdp leader Frederic Weisbecker
2021-02-23 0:10 ` [PATCH 09/13] rcu/nocb: Cancel nocb_timer upon nocb_gp wakeup Frederic Weisbecker
2021-02-23 0:10 ` [PATCH 10/13] rcu/nocb: Delete bypass_timer " Frederic Weisbecker
2021-03-03 1:24 ` Paul E. McKenney
2021-03-10 22:17 ` Frederic Weisbecker
2021-03-15 14:53 ` Boqun Feng
2021-03-15 22:56 ` Frederic Weisbecker
2021-03-16 0:02 ` Paul E. McKenney
2021-02-23 0:10 ` [PATCH 11/13] rcu/nocb: Only cancel nocb timer if not polling Frederic Weisbecker
2021-03-03 1:22 ` Paul E. McKenney
2021-03-10 22:08 ` Frederic Weisbecker
2021-02-23 0:10 ` [PATCH 12/13] rcu/nocb: Prepare for finegrained deferred wakeup Frederic Weisbecker
2021-03-16 3:02 ` Paul E. McKenney
2021-03-16 11:45 ` Frederic Weisbecker [this message]
2021-03-16 14:02 ` Paul E. McKenney
2021-02-23 0:10 ` [PATCH 13/13] rcu/nocb: Unify timers Frederic Weisbecker
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