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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_plugin.h
parentba49df4767d4fa5bbd2af3a51709fb81f94264ec (diff)
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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_plugin.h')
-rw-r--r--kernel/rcutree_plugin.h7
1 files changed, 5 insertions, 2 deletions
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index f92115488187..c177ba0cce9a 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -679,7 +679,10 @@ void synchronize_rcu(void)
"Illegal synchronize_rcu() in RCU read-side critical section");
if (!rcu_scheduler_active)
return;
- wait_rcu_gp(call_rcu);
+ if (rcu_expedited)
+ synchronize_rcu_expedited();
+ else
+ wait_rcu_gp(call_rcu);
}
EXPORT_SYMBOL_GPL(synchronize_rcu);
@@ -831,7 +834,7 @@ void synchronize_rcu_expedited(void)
udelay(trycount * num_online_cpus());
} else {
put_online_cpus();
- synchronize_rcu();
+ wait_rcu_gp(call_rcu);
return;
}
}