diff options
| author | Frederic Weisbecker <frederic@kernel.org> | 2020-11-13 13:13:24 +0100 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2021-01-06 16:24:59 -0800 |
| commit | 314202f84ddd61e4d7576ef62570ad2e2d9db06b (patch) | |
| tree | 8822a732e2aa150c6cf5039abd2dc5118fa0630b /kernel/rcu | |
| parent | 69cdea873cde261586a2cae2440178df1a313bbe (diff) | |
rcu/nocb: Flush bypass before setting SEGCBLIST_SOFTIRQ_ONLY
This commit flushes the bypass queue and sets state to avoid its being
refilled before switching to the final de-offloaded state. To avoid
refilling, this commit sets SEGCBLIST_SOFTIRQ_ONLY before re-enabling
IRQs.
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>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Inspired-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index c88ad628595b..35dc9b31e9a4 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -2339,12 +2339,21 @@ static int __rcu_nocb_rdp_deoffload(struct rcu_data *rdp) swait_event_exclusive(rdp->nocb_state_wq, !rcu_segcblist_test_flags(cblist, SEGCBLIST_KTHREAD_CB | SEGCBLIST_KTHREAD_GP)); - /* Make sure nocb timer won't stay around */ rcu_nocb_lock_irqsave(rdp, flags); + /* Make sure nocb timer won't stay around */ WRITE_ONCE(rdp->nocb_defer_wakeup, RCU_NOCB_WAKE_OFF); rcu_nocb_unlock_irqrestore(rdp, flags); del_timer_sync(&rdp->nocb_timer); + /* + * Flush bypass. While IRQs are disabled and once we set + * SEGCBLIST_SOFTIRQ_ONLY, no callback is supposed to be + * enqueued on bypass. + */ + rcu_nocb_lock_irqsave(rdp, flags); + rcu_nocb_flush_bypass(rdp, NULL, jiffies); + rcu_nocb_unlock_irqrestore(rdp, flags); + return ret; } |