Re: [PATCH 5/5][RFC] rcu: start new grace period from rcu_pending()

[Oleg Nesterov <oleg@tv-sign.ru>]

Oleg Nesterov wrote:
>
> I think it is better to set ->qs_pending = 1 directly in __rcu_pending():

This patch has a bug. I am sending a trivial fix, but now I am not
sure myself that 1 timer tick saved worth the code uglification.

[PATCH 6/5] rcu: start new grace period from rcu_pending() fix

We should not miss __rcu_pending(&rcu_bh_ctrlblk) in rcu_pending().

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>

--- 2.6.15/kernel/rcupdate.c~6_FIX	2006-01-09 00:26:44.000000000 +0300
+++ 2.6.15/kernel/rcupdate.c	2006-01-09 19:19:27.000000000 +0300
@@ -464,7 +464,7 @@ static int __rcu_pending(struct rcu_ctrl
 
 int rcu_pending(int cpu)
 {
-	return __rcu_pending(&rcu_ctrlblk, &per_cpu(rcu_data, cpu)) ||
+	return __rcu_pending(&rcu_ctrlblk, &per_cpu(rcu_data, cpu)) |
 		__rcu_pending(&rcu_bh_ctrlblk, &per_cpu(rcu_bh_data, cpu));
 }