rcu: Add a module parameter to force use of expedited RCU primitives
There have been some embedded applications that would benefit from
use of expedited grace-period primitives. In some ways, this is
similar to synchronize_net() doing either a normal or an expedited
grace period depending on lock state, but with control outside of
the kernel.
This commit therefore adds rcu_expedited boot and sysfs parameters
that cause the kernel to substitute expedited primitives for the
normal grace-period primitives.
[ paulmck: Add trace/event/rcu.h to kernel/srcu.c to avoid build error.
Get rid of infinite loop through contention path.]
Signed-off-by: Antti P Miettinen <amiettinen@nvidia.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index 29ca1c6..a2cf761 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -46,12 +46,15 @@
#include <linux/export.h>
#include <linux/hardirq.h>
#include <linux/delay.h>
+#include <linux/module.h>
#define CREATE_TRACE_POINTS
#include <trace/events/rcu.h>
#include "rcu.h"
+module_param(rcu_expedited, int, 0);
+
#ifdef CONFIG_PREEMPT_RCU
/*
