From 3705b88db0d7cc4a097c32d9e554054103d3f807 Mon Sep 17 00:00:00 2001 From: Antti P Miettinen Date: Fri, 5 Oct 2012 09:59:15 +0300 Subject: 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 Signed-off-by: Paul E. McKenney --- kernel/srcu.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'kernel/srcu.c') diff --git a/kernel/srcu.c b/kernel/srcu.c index 97c465ebd844..de9074047c92 100644 --- a/kernel/srcu.c +++ b/kernel/srcu.c @@ -34,6 +34,10 @@ #include #include +#include + +#include "rcu.h" + /* * Initialize an rcu_batch structure to empty. */ @@ -464,7 +468,9 @@ static void __synchronize_srcu(struct srcu_struct *sp, int trycount) */ void synchronize_srcu(struct srcu_struct *sp) { - __synchronize_srcu(sp, SYNCHRONIZE_SRCU_TRYCOUNT); + __synchronize_srcu(sp, rcu_expedited + ? SYNCHRONIZE_SRCU_EXP_TRYCOUNT + : SYNCHRONIZE_SRCU_TRYCOUNT); } EXPORT_SYMBOL_GPL(synchronize_srcu); -- cgit v1.2.3