rcu: Changes from reviews: avoid casts, fix/add warnings, improve comments
Changes suggested by review comments from Josh Triplett and
Mathieu Desnoyers.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Josh Triplett <josh@joshtriplett.org>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
LKML-Reference: <20090827220012.GA30525@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 04343be..4778936 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -92,7 +92,7 @@
rnp = rdp->mynode;
spin_lock(&rnp->lock);
t->rcu_read_unlock_special |= RCU_READ_UNLOCK_BLOCKED;
- t->rcu_blocked_node = (void *)rnp;
+ t->rcu_blocked_node = rnp;
/*
* If this CPU has already checked in, then this task
@@ -176,9 +176,9 @@
* most one time. So at most two passes through loop.
*/
for (;;) {
- rnp = (struct rcu_node *)t->rcu_blocked_node;
+ rnp = t->rcu_blocked_node;
spin_lock(&rnp->lock);
- if (rnp == (struct rcu_node *)t->rcu_blocked_node)
+ if (rnp == t->rcu_blocked_node)
break;
spin_unlock(&rnp->lock);
}
@@ -288,8 +288,10 @@
struct rcu_node *rnp_root = rcu_get_root(rsp);
struct task_struct *tp;
- if (rnp == rnp_root)
+ if (rnp == rnp_root) {
+ WARN_ONCE(1, "Last CPU thought to be offlined?");
return; /* Shouldn't happen: at least one CPU online. */
+ }
/*
* Move tasks up to root rcu_node. Rely on the fact that the