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Add a boot parameter that makes rcu_initiate_boost() do nothing, giving that scenario a way to break boosting. Signed-off-by: Joel Fernandes --- kernel/rcu/tree_plugin.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index ae5d21bae7bc..04a58dd003f4 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -1270,6 +1270,9 @@ static int rcu_boost_kthread(void *arg) return 0; } +static bool boost_disable; +module_param(boost_disable, bool, 0444); + /* * Check to see if it is time to start boosting RCU readers that are * blocking the current grace period, and, if so, tell the per-rcu_node @@ -1284,7 +1287,7 @@ static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags) __releases(rnp->lock) { raw_lockdep_assert_held_rcu_node(rnp); - if (!rnp->boost_kthread_task || + if (boost_disable || !rnp->boost_kthread_task || (!rcu_preempt_blocked_readers_cgp(rnp) && !rnp->exp_tasks)) { raw_spin_unlock_irqrestore_rcu_node(rnp, flags); return; -- 2.54.0