Re: [PATCH] rcu: simplify the usage of percpu data

["Paul E. McKenney" <paulmck@linux.vnet.ibm.com>]

On Mon, Jun 28, 2010 at 09:56:54AM -0700, Paul E. McKenney wrote:
> On Mon, Jun 28, 2010 at 10:38:39AM +0200, Tejun Heo wrote:
> > On 06/28/2010 10:25 AM, Lai Jiangshan wrote:
> > > &percpu_data is compatible with allocated percpu data.
> > > 
> > > And we use it and remove the "rda[NR_CPUS]" array.
> > > 
> > > Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
> > 
> > Looks good to me.
> > 
> > Reviewed-by: Tejun Heo <tj@kernel.org>
> 
> Thank you both!!!  I have queued this.

FYI, I added the patchlet below to make it build for CONFIG_RCU_TRACE
kernels.

							Thanx, Paul

------------------------------------------------------------------------

rcu: apply ->rda changes to rcutree_trace.c
    
The print_rcu_pendings() function used the ->rda[] array, so this
commit makes it instead use per_cpu_ptr().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c
index 36c95b4..458e032 100644
--- a/kernel/rcutree_trace.c
+++ b/kernel/rcutree_trace.c
@@ -262,7 +262,7 @@ static void print_rcu_pendings(struct seq_file *m, struct rcu_state *rsp)
 	struct rcu_data *rdp;
 
 	for_each_possible_cpu(cpu) {
-		rdp = rsp->rda[cpu];
+		rdp = per_cpu_ptr(rsp->rda, cpu);
 		if (rdp->beenonline)
 			print_one_rcu_pending(m, rdp);
 	}