printk ratelimiting rewrite

All ratelimit user use same jiffies and burst params, so some messages
(callbacks) will be lost.

For example:
a call printk_ratelimit(5 * HZ, 1)
b call printk_ratelimit(5 * HZ, 1) before the 5*HZ timeout of a, then b will
will be supressed.

- rewrite __ratelimit, and use a ratelimit_state as parameter.  Thanks for
  hints from andrew.

- Add WARN_ON_RATELIMIT, update rcupreempt.h

- remove __printk_ratelimit

- use __ratelimit in net_ratelimit

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 7 insertions, 2 deletions

diff --git a/include/linux/rcupreempt.h b/include/linux/rcupreempt.h
index f04b64eca636..0967f03b0705 100644
--- a/include/linux/rcupreempt.h
+++ b/include/linux/rcupreempt.h
@@ -115,16 +115,21 @@ DECLARE_PER_CPU(struct rcu_dyntick_sched, rcu_dyntick_sched);
 
 static inline void rcu_enter_nohz(void)
 {
+        static DEFINE_RATELIMIT_STATE(rs, 10 * HZ, 1);
+
         smp_mb(); /* CPUs seeing ++ must see prior RCU read-side crit sects */
         __get_cpu_var(rcu_dyntick_sched).dynticks++;
-        WARN_ON(__get_cpu_var(rcu_dyntick_sched).dynticks & 0x1);
+        WARN_ON_RATELIMIT(__get_cpu_var(rcu_dyntick_sched).dynticks & 0x1, &rs);
 }
 
 static inline void rcu_exit_nohz(void)
 {
+        static DEFINE_RATELIMIT_STATE(rs, 10 * HZ, 1);
+
         smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */
         __get_cpu_var(rcu_dyntick_sched).dynticks++;
-        WARN_ON(!(__get_cpu_var(rcu_dyntick_sched).dynticks & 0x1));
+        WARN_ON_RATELIMIT(!(__get_cpu_var(rcu_dyntick_sched).dynticks & 0x1),
+                                &rs);
 }
 
 #else /* CONFIG_NO_HZ */