Messages in this thread Patch in this message | | | From | Frederic Weisbecker <> | Subject | [PATCH 06/10] rcu: Make nocb_cb kthread parkable | Date | Wed, 13 May 2020 18:47:10 +0200 |
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This will be necessary to correctly implement rdp de-offloading. We don't want rcu_do_batch() in nocb_cb kthread to race with local rcu_do_batch().
Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Joel Fernandes <joel@joelfernandes.org> --- kernel/rcu/tree_plugin.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 1dd3fdd675a1..43ecc047af26 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -2104,7 +2104,9 @@ static void nocb_cb_wait(struct rcu_data *rdp) if (needwake_gp) rcu_gp_kthread_wake(); swait_event_interruptible_exclusive(rdp->nocb_cb_wq, - !READ_ONCE(rdp->nocb_cb_sleep)); + !READ_ONCE(rdp->nocb_cb_sleep) || + kthread_should_park()); + if (!smp_load_acquire(&rdp->nocb_cb_sleep)) { /* VVV */ /* ^^^ Ensure CB invocation follows _sleep test. */ return; @@ -2125,6 +2127,8 @@ static int rcu_nocb_cb_kthread(void *arg) // if there are no more ready callbacks, waits for them. for (;;) { nocb_cb_wait(rdp); + if (kthread_should_park()) + kthread_parkme(); cond_resched_tasks_rcu_qs(); } return 0; -- 2.25.0
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