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,
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" <paulmck@kernel.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Scott Wood <swood@redhat.com>
Subject: [PATCH tip/core/rcu 3/4] rcu: Run rcuo kthreads at elevated priority in CONFIG_RCU_BOOST kernels
Date: Tue, 19 Jan 2021 20:32:35 -0800 [thread overview]
Message-ID: <20210120043236.7254-3-paulmck@kernel.org> (raw)
In-Reply-To: <20210120043144.GA7045@paulmck-ThinkPad-P72>
From: "Paul E. McKenney" <paulmck@kernel.org>
The priority level of the rcuo kthreads is the system administrator's
responsibility, but kernels that priority-boost RCU readers probably need
the rcuo kthreads running at the rcutree.kthread_prio level. This commit
therefore sets these kthreads to that priority level at creation time,
providing a sensible default. The system administrator is free to adjust
as needed at any time.
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Scott Wood <swood@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
kernel/rcu/tree_plugin.h | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index fca31c6..7e33dae0 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -2197,6 +2197,7 @@ static int rcu_nocb_gp_kthread(void *arg)
{
struct rcu_data *rdp = arg;
+ rcu_cpu_kthread_setup(-1);
for (;;) {
WRITE_ONCE(rdp->nocb_gp_loops, rdp->nocb_gp_loops + 1);
nocb_gp_wait(rdp);
@@ -2298,6 +2299,7 @@ static int rcu_nocb_cb_kthread(void *arg)
// Each pass through this loop does one callback batch, and,
// if there are no more ready callbacks, waits for them.
+ rcu_cpu_kthread_setup(-1);
for (;;) {
nocb_cb_wait(rdp);
cond_resched_tasks_rcu_qs();
--
2.9.5
next prev parent reply other threads:[~2021-01-20 4:33 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-20 4:31 [PATCH tip/core/rcu 0/4] Fix RCU priority boosting Paul E. McKenney
2021-01-20 4:32 ` [PATCH tip/core/rcu 1/4] rcu: Expedite deboost in case of deferred quiescent state paulmck
2021-01-27 2:42 ` Boqun Feng
2021-01-27 4:40 ` Paul E. McKenney
2021-01-27 7:05 ` Boqun Feng
2021-01-27 19:18 ` Paul E. McKenney
2021-01-28 1:11 ` Boqun Feng
2021-01-28 1:28 ` Paul E. McKenney
2021-01-20 4:32 ` [PATCH tip/core/rcu 2/4] rcutorture: Make TREE03 use real-time tree.use_softirq setting paulmck
2021-01-20 4:32 ` paulmck [this message]
2021-01-20 4:32 ` [PATCH tip/core/rcu 4/4] rcutorture: Fix testing of RCU priority boosting paulmck
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