aboutsummaryrefslogtreecommitdiff
path: root/kernel/rcutree.c
diff options
context:
space:
mode:
authorAntti P Miettinen <ananaza@iki.fi>2012-10-05 09:59:15 +0300
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2012-10-23 14:54:08 -0700
commit3705b88db0d7cc4a097c32d9e554054103d3f807 (patch)
treef3baf8c94363506964c9f944496267f74cdee47c /kernel/rcutree.c
parentba49df4767d4fa5bbd2af3a51709fb81f94264ec (diff)
downloadvexpress-lsk-3705b88db0d7cc4a097c32d9e554054103d3f807.tar.gz
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>
Diffstat (limited to 'kernel/rcutree.c')
-rw-r--r--kernel/rcutree.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 74df86bd920..f9c17c39953 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -2224,7 +2224,10 @@ void synchronize_sched(void)
"Illegal synchronize_sched() in RCU-sched read-side critical section");
if (rcu_blocking_is_gp())
return;
- wait_rcu_gp(call_rcu_sched);
+ if (rcu_expedited)
+ synchronize_sched_expedited();
+ else
+ wait_rcu_gp(call_rcu_sched);
}
EXPORT_SYMBOL_GPL(synchronize_sched);
@@ -2245,7 +2248,10 @@ void synchronize_rcu_bh(void)
"Illegal synchronize_rcu_bh() in RCU-bh read-side critical section");
if (rcu_blocking_is_gp())
return;
- wait_rcu_gp(call_rcu_bh);
+ if (rcu_expedited)
+ synchronize_rcu_bh_expedited();
+ else
+ wait_rcu_gp(call_rcu_bh);
}
EXPORT_SYMBOL_GPL(synchronize_rcu_bh);
@@ -2328,7 +2334,7 @@ void synchronize_sched_expedited(void)
if (trycount++ < 10) {
udelay(trycount * num_online_cpus());
} else {
- synchronize_sched();
+ wait_rcu_gp(call_rcu_sched);
return;
}