From: Frederic Weisbecker <frederic@kernel.org>
To: "Paul E . McKenney" <paulmck@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Frederic Weisbecker <frederic@kernel.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Uladzislau Rezki <urezki@gmail.com>,
Valentin Schneider <valentin.schneider@arm.com>,
Thomas Gleixner <tglx@linutronix.de>,
Boqun Feng <boqun.feng@gmail.com>,
Neeraj Upadhyay <neeraju@codeaurora.org>,
Josh Triplett <josh@joshtriplett.org>,
Joel Fernandes <joel@joelfernandes.org>,
rcu@vger.kernel.org
Subject: [PATCH 00/11] rcu: Make rcu_core() safe in PREEMPT_RT with NOCB + a few other fixes
Date: Thu, 30 Sep 2021 00:10:01 +0200 [thread overview]
Message-ID: <20210929221012.228270-1-frederic@kernel.org> (raw)
PREEMPT_RT has made rcu_core() preemptible, making it unsafe against
concurrent NOCB (de-)offloading.
Thomas suggested to drop the local_lock() based solution and simply
check the offloaded state while context looks safe but that's not
enough. Here is a bit of rework.
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git
rcu/rt
HEAD: aac1c58961446c731f2e989bd822ca1fd2659bad
Thanks,
Frederic
---
Frederic Weisbecker (10):
rcu/nocb: Make local rcu_nocb_lock_irqsave() safe against concurrent deoffloading
rcu/nocb: Prepare state machine for a new step
rcu/nocb: Invoke rcu_core() at the start of deoffloading
rcu/nocb: Make rcu_core() callbacks acceleration (de-)offloading safe
rcu/nocb: Check a stable offloaded state to manipulate qlen_last_fqs_check
rcu/nocb: Use appropriate rcu_nocb_lock_irqsave()
rcu/nocb: Limit number of softirq callbacks only on softirq
rcu: Fix callbacks processing time limit retaining cond_resched()
rcu: Apply callbacks processing time limit only on softirq
rcu/nocb: Don't invoke local rcu core on callback overload from nocb kthread
Thomas Gleixner (1):
rcu/nocb: Make rcu_core() callbacks acceleration preempt-safe
include/linux/rcu_segcblist.h | 51 +++++++++++++++++++-------
kernel/rcu/rcu_segcblist.c | 10 ++---
kernel/rcu/rcu_segcblist.h | 7 ++--
kernel/rcu/tree.c | 85 ++++++++++++++++++++++++++++++-------------
kernel/rcu/tree.h | 16 +++++---
kernel/rcu/tree_nocb.h | 29 ++++++++++++---
6 files changed, 136 insertions(+), 62 deletions(-)
next reply other threads:[~2021-09-29 22:10 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-29 22:10 Frederic Weisbecker [this message]
2021-09-29 22:10 ` [PATCH 01/11] rcu/nocb: Make local rcu_nocb_lock_irqsave() safe against concurrent deoffloading Frederic Weisbecker
2021-09-29 22:10 ` [PATCH 02/11] rcu/nocb: Prepare state machine for a new step Frederic Weisbecker
2021-10-01 17:48 ` Valentin Schneider
2021-10-04 11:35 ` Frederic Weisbecker
2021-09-29 22:10 ` [PATCH 03/11] rcu/nocb: Invoke rcu_core() at the start of deoffloading Frederic Weisbecker
2021-10-01 17:50 ` Valentin Schneider
2021-10-04 12:41 ` Frederic Weisbecker
2021-09-29 22:10 ` [PATCH 04/11] rcu/nocb: Make rcu_core() callbacks acceleration preempt-safe Frederic Weisbecker
2021-10-01 17:50 ` Valentin Schneider
2021-09-29 22:10 ` [PATCH 05/11] rcu/nocb: Make rcu_core() callbacks acceleration (de-)offloading safe Frederic Weisbecker
2021-10-01 17:50 ` Valentin Schneider
2021-10-04 13:14 ` Frederic Weisbecker
2021-09-29 22:10 ` [RFC PATCH 06/11] rcu/nocb: Check a stable offloaded state to manipulate qlen_last_fqs_check Frederic Weisbecker
2021-09-29 22:10 ` [PATCH 07/11] rcu/nocb: Use appropriate rcu_nocb_lock_irqsave() Frederic Weisbecker
2021-10-01 17:50 ` Valentin Schneider
2021-10-04 13:33 ` Frederic Weisbecker
2021-09-29 22:10 ` [PATCH 08/11] rcu/nocb: Limit number of softirq callbacks only on softirq Frederic Weisbecker
2021-10-01 17:51 ` Valentin Schneider
2021-10-04 13:42 ` Frederic Weisbecker
2021-10-05 20:55 ` Paul E. McKenney
2021-09-29 22:10 ` [PATCH 09/11] rcu: Fix callbacks processing time limit retaining cond_resched() Frederic Weisbecker
2021-10-01 17:51 ` Valentin Schneider
2021-09-29 22:10 ` [PATCH 10/11] rcu: Apply callbacks processing time limit only on softirq Frederic Weisbecker
2021-10-01 17:51 ` Valentin Schneider
2021-10-04 13:47 ` Frederic Weisbecker
2021-10-06 15:12 ` Valentin Schneider
2021-10-07 0:18 ` Frederic Weisbecker
2021-09-29 22:10 ` [PATCH 11/11] rcu/nocb: Don't invoke local rcu core on callback overload from nocb kthread Frederic Weisbecker
2021-09-30 15:37 ` Sebastian Andrzej Siewior
2021-10-11 12:11 ` Frederic Weisbecker
2021-10-01 17:47 ` [PATCH 00/11] rcu: Make rcu_core() safe in PREEMPT_RT with NOCB + a few other fixes Valentin Schneider
2021-10-08 14:03 ` Valentin Schneider
2021-10-08 15:49 ` Paul E. McKenney
2021-10-06 15:13 ` Paul E. McKenney
2021-10-07 8:49 ` Sebastian Andrzej Siewior
2021-10-07 19:12 ` Paul E. McKenney
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