[RT,05/16] rcu: Dont allow to change rcu_normal_after_boot on RT
diff mbox series

Message ID 20190719214956.816542002@goodmis.org
State New
Headers show
Series
  • Linux 4.19.59-rt24-rc1
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Commit Message

Steven Rostedt July 19, 2019, 9:49 p.m. UTC
4.19.59-rt24-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

[ Upstream commit c6c058c10577815a2491ce661876cff00a4c3b15 ]

On RT rcu_normal_after_boot is enabled by default.
Don't allow to disable it on RT because the "expedited rcu" would
introduce latency spikes.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/rcu/update.c | 2 ++
 1 file changed, 2 insertions(+)

Patch
diff mbox series

diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index 16d8dba23329..ed75addd3ccd 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -69,7 +69,9 @@  module_param(rcu_expedited, int, 0);
 extern int rcu_normal; /* from sysctl */
 module_param(rcu_normal, int, 0);
 static int rcu_normal_after_boot = IS_ENABLED(CONFIG_PREEMPT_RT_FULL);
+#ifndef CONFIG_PREEMPT_RT_FULL
 module_param(rcu_normal_after_boot, int, 0);
+#endif
 #endif /* #ifndef CONFIG_TINY_RCU */
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC