rcu: Augment rcu_batch_end tracing for idle and callback state

The current rcu_batch_end event trace records only the name of the RCU
flavor and the total number of callbacks that remain queued on the
current CPU.  This is insufficient for testing and tuning the new
dyntick-idle RCU_FAST_NO_HZ code, so this commit adds idle state along
with whether or not any of the callbacks that were ready to invoke
at the beginning of rcu_do_batch() are still queued.

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

1 files changed, 8 insertions, 2 deletions

diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c
index e5bd94954fa3..977296dca0a4 100644
--- a/kernel/rcutiny.c
+++ b/kernel/rcutiny.c
@@ -259,7 +259,11 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp)
         /* If no RCU callbacks ready to invoke, just return. */
         if (&rcp->rcucblist == rcp->donetail) {
                 RCU_TRACE(trace_rcu_batch_start(rcp->name, 0, -1));
-                RCU_TRACE(trace_rcu_batch_end(rcp->name, 0));
+                RCU_TRACE(trace_rcu_batch_end(rcp->name, 0,
+                                              ACCESS_ONCE(rcp->rcucblist),
+                                              need_resched(),
+                                              is_idle_task(current),
+                                              rcu_is_callbacks_kthread()));
                 return;
         }
 
@@ -288,7 +292,9 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp)
                 RCU_TRACE(cb_count++);
         }
         RCU_TRACE(rcu_trace_sub_qlen(rcp, cb_count));
-        RCU_TRACE(trace_rcu_batch_end(rcp->name, cb_count));
+        RCU_TRACE(trace_rcu_batch_end(rcp->name, cb_count, 0, need_resched(),
+                                      is_idle_task(current),
+                                      rcu_is_callbacks_kthread()));
 }
 
 static void rcu_process_callbacks(struct softirq_action *unused)