diff options
| author | Qais Yousef <qyousef@layalina.io> | 2023-12-03 01:12:52 +0000 |
|---|---|---|
| committer | Boqun Feng <boqun.feng@gmail.com> | 2024-02-14 08:00:57 -0800 |
| commit | 7f66f099de4dc4b1a66a3f94e6db16409924a6f8 (patch) | |
| tree | 5ca3a31d12df9a65d32b9001372210857195f393 /kernel/rcu/tree.c | |
| parent | 499d7e7e83d25fcf0fa1a8c0be6857a84cbf6a4a (diff) | |
rcu: Provide a boot time parameter to control lazy RCU
To allow more flexible arrangements while still provide a single kernel
for distros, provide a boot time parameter to enable/disable lazy RCU.
Specify:
rcutree.enable_rcu_lazy=[y|1|n|0]
Which also requires
rcu_nocbs=all
at boot time to enable/disable lazy RCU.
To disable it by default at build time when CONFIG_RCU_LAZY=y, the new
CONFIG_RCU_LAZY_DEFAULT_OFF can be used.
Signed-off-by: Qais Yousef (Google) <qyousef@layalina.io>
Tested-by: Andrea Righi <andrea.righi@canonical.com>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Diffstat (limited to 'kernel/rcu/tree.c')
| -rw-r--r-- | kernel/rcu/tree.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index b2bccfd37c38..41c50a6c607e 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2753,6 +2753,9 @@ __call_rcu_common(struct rcu_head *head, rcu_callback_t func, bool lazy_in) } #ifdef CONFIG_RCU_LAZY +static bool enable_rcu_lazy __read_mostly = !IS_ENABLED(CONFIG_RCU_LAZY_DEFAULT_OFF); +module_param(enable_rcu_lazy, bool, 0444); + /** * call_rcu_hurry() - Queue RCU callback for invocation after grace period, and * flush all lazy callbacks (including the new one) to the main ->cblist while @@ -2778,6 +2781,8 @@ void call_rcu_hurry(struct rcu_head *head, rcu_callback_t func) __call_rcu_common(head, func, false); } EXPORT_SYMBOL_GPL(call_rcu_hurry); +#else +#define enable_rcu_lazy false #endif /** @@ -2826,7 +2831,7 @@ EXPORT_SYMBOL_GPL(call_rcu_hurry); */ void call_rcu(struct rcu_head *head, rcu_callback_t func) { - __call_rcu_common(head, func, IS_ENABLED(CONFIG_RCU_LAZY)); + __call_rcu_common(head, func, enable_rcu_lazy); } EXPORT_SYMBOL_GPL(call_rcu); |