From: Paul E. McKenney Date: Fri, 1 Aug 2008 21:10:02 +0000 (-0700) Subject: rcu: fixes to include/linux/rcupreempt.h X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=ff9cf2ce7afe76435d66c898cc9dacaa68e79d41;p=linux-beck.git rcu: fixes to include/linux/rcupreempt.h Hello! Compared tip/core/rcu to my latest patchset, and found the following issues: o the memory barrier in rcu_exit_nohz() somehow got out of place (it is correct in mainline as of 2.6.26-rc7). o There is a duplicate declaration of rcu_dyntick_sched. The attached patch fixes these. Signed-off-by: Paul E. McKenney Signed-off-by: Ingo Molnar --- diff --git a/include/linux/rcupreempt.h b/include/linux/rcupreempt.h index 0967f03b0705..addb5e282f39 100644 --- a/include/linux/rcupreempt.h +++ b/include/linux/rcupreempt.h @@ -111,7 +111,6 @@ extern struct rcupreempt_trace *rcupreempt_trace_cpu(int cpu); struct softirq_action; #ifdef CONFIG_NO_HZ -DECLARE_PER_CPU(struct rcu_dyntick_sched, rcu_dyntick_sched); static inline void rcu_enter_nohz(void) { @@ -126,8 +125,8 @@ 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++; + smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */ WARN_ON_RATELIMIT(!(__get_cpu_var(rcu_dyntick_sched).dynticks & 0x1), &rs); }