[PATCH tip/core/rcu 10/10] rcu: Initialize tiny RCU stall-warning timeouts at boot

From: Paul E. McKenney
Date: Wed Jan 07 2015 - 12:54:48 EST


From: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>

The current tiny RCU stall-warning code assumes that the jiffies counter
starts at zero, however, it is sometimes initialized to other values,
for example, -30,000. This commit therefore changes rcu_init() to
invoke reset_cpu_stall_ticks() for both flavors of RCU to initialize
the stall-warning times properly at boot.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
---
kernel/rcu/tiny.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c
index 0db5649f8817..fc0f2c07af3a 100644
--- a/kernel/rcu/tiny.c
+++ b/kernel/rcu/tiny.c
@@ -383,6 +383,8 @@ EXPORT_SYMBOL_GPL(call_rcu_bh);
void __init rcu_init(void)
{
open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);
+ RCU_TRACE(reset_cpu_stall_ticks(&rcu_sched_ctrlblk));
+ RCU_TRACE(reset_cpu_stall_ticks(&rcu_bh_ctrlblk));

rcu_early_boot_tests();
}
--
1.8.1.5

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