rcu: Fix accelerated grace periods for last non-dynticked CPU

It is invalid to invoke __rcu_process_callbacks() with irqs
disabled, so do it indirectly via raise_softirq().  This
requires a state-machine implementation to cycle through the
grace-period machinery the required number of times.

Located-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1267231138-27856-1-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 1 insertions, 0 deletions

diff --git a/kernel/rcutree.h b/kernel/rcutree.h
index 2ceb08388582..1439eb504c22 100644
--- a/kernel/rcutree.h
+++ b/kernel/rcutree.h
@@ -373,5 +373,6 @@ static int rcu_preempt_needs_cpu(int cpu);
 static void __cpuinit rcu_preempt_init_percpu_data(int cpu);
 static void rcu_preempt_send_cbs_to_orphanage(void);
 static void __init __rcu_init_preempt(void);
+static void rcu_needs_cpu_flush(void);
 
 #endif /* #ifndef RCU_TREE_NONCORE */