From: "Paul E. McKenney" <paulmck@linux.ibm.com>
To: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, 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,
bigeasy@linutronix.de
Subject: [PATCH RFC tip/core/rcu 0/2] Real-time elimination of RCU_SOFTIRQ
Date: Fri, 29 Mar 2019 11:26:08 -0700 [thread overview]
Message-ID: <20190329182608.GA23877@linux.ibm.com> (raw)
Hello!
This series is an early posting of code to add a boot-time option to
move RCU's softirq processing to per-CPU kthreads. This is not done
by default for performance reasons, nor are these reasons theoretical.
In fact, earlier attempts to do just this were not met with silence.
The patches are as follows:
1. Enable elimination of Tree-RCU softirq processing via a new
rcutree.use_softirq kernel boot parameter. This defaults to 1,
so boot with "rcutree.use_softirq=0" to move RCU_SOFTIRQ work
to the rcuc kthreads. Courtesy of Sebastian Andrzej Siewior.
2. Improve wakeup-safety checks in rcu_read_unlock_special(),
thus allowing both rcuc kthreads and reasonably snappy
expedited RCU grace periods.
Thanx, Paul
------------------------------------------------------------------------
Documentation/admin-guide/kernel-parameters.txt | 6
include/linux/sched.h | 2
kernel/rcu/tree.c | 138 +++++++++++++++++++--
kernel/rcu/tree.h | 2
kernel/rcu/tree_plugin.h | 153 ++++--------------------
5 files changed, 161 insertions(+), 140 deletions(-)
next reply other threads:[~2019-03-29 18:26 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-29 18:26 Paul E. McKenney [this message]
2019-03-29 18:26 ` [PATCH tip/core/rcu 1/2] rcu: Enable elimination of Tree-RCU softirq processing Paul E. McKenney
2019-03-29 18:26 ` [PATCH tip/core/rcu 2/2] rcu: Check for wakeup-safe conditions in rcu_read_unlock_special() Paul E. McKenney
2019-04-01 8:32 ` Peter Zijlstra
2019-04-01 17:22 ` Paul E. McKenney
2019-04-01 19:03 ` Paul E. McKenney
2019-04-02 7:09 ` Peter Zijlstra
2019-04-02 13:18 ` Paul E. McKenney
2019-04-03 9:50 ` Peter Zijlstra
2019-04-03 16:25 ` Paul E. McKenney
2019-04-04 19:49 ` Paul E. McKenney
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