[PATCH 1/2] sched: Add cond_resched_rcu_lock() helper

From: Simon Horman
Date: Thu Apr 25 2013 - 21:46:10 EST


This is intended for use in loops which read data protected by RCU and may
have a large number of iterations. Such an example is dumping the list of
connections known to IPVS: ip_vs_conn_array() and ip_vs_conn_seq_next().

As suggested by Eric Dumazet.

Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Cc: Julian Anastasov <ja@xxxxxx>
Signed-off-by: Simon Horman <horms@xxxxxxxxxxxx>
---
include/linux/sched.h | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index e692a02..7eec4c7 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2787,3 +2787,12 @@ static inline unsigned long rlimit_max(unsigned int limit)
}

#endif
+
+static void inline cond_resched_rcu_lock(void)
+{
+ if (need_resched()) {
+ rcu_read_unlock();
+ cond_resched();
+ rcu_read_lock();
+ }
+}
--
1.8.2.1

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