rcu: Add event-trace markers to TREE_RCU kthreads

Add event-trace markers to TREE_RCU kthreads to allow including these
kthread's CPU time in the utilization calculations.

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

diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h
index 508824e..ac52aba 100644 (file)
--- a/include/trace/events/rcu.h
+++ b/include/trace/events/rcu.h
@@ -13,6 +13,9 @@
  * "Start <activity>" -- Mark the start of the specified activity,
  *                      such as "context switch".  Nesting is permitted.
  * "End <activity>" -- Mark the end of the specified activity.
+ *
+ * An "@" character within "<activity>" is a comment character: Data
+ * reduction scripts will ignore the "@" and the remainder of the line.
  */
 TRACE_EVENT(rcu_utilization,
 

diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index ecd48a2..94d9ca1 100644 (file)
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -1219,9 +1219,12 @@ static int rcu_boost_kthread(void *arg)
        int spincnt = 0;
        int more2boost;
 
+       trace_rcu_utilization("Start boost kthread@init");
        for (;;) {
                rnp->boost_kthread_status = RCU_KTHREAD_WAITING;
+               trace_rcu_utilization("End boost kthread@rcu_wait");
                rcu_wait(rnp->boost_tasks || rnp->exp_tasks);
+               trace_rcu_utilization("Start boost kthread@rcu_wait");
                rnp->boost_kthread_status = RCU_KTHREAD_RUNNING;
                more2boost = rcu_boost(rnp);
                if (more2boost)
@@ -1229,11 +1232,14 @@ static int rcu_boost_kthread(void *arg)
                else
                        spincnt = 0;
                if (spincnt > 10) {
+                       trace_rcu_utilization("End boost kthread@rcu_yield");
                        rcu_yield(rcu_boost_kthread_timer, (unsigned long)rnp);
+                       trace_rcu_utilization("Start boost kthread@rcu_yield");
                        spincnt = 0;
                }
        }
        /* NOTREACHED */
+       trace_rcu_utilization("End boost kthread@notreached");
        return 0;
 }
 
@@ -1490,9 +1496,12 @@ static int rcu_cpu_kthread(void *arg)
        char work;
        char *workp = &per_cpu(rcu_cpu_has_work, cpu);
 
+       trace_rcu_utilization("Start CPU kthread@init");
        for (;;) {
                *statusp = RCU_KTHREAD_WAITING;
+               trace_rcu_utilization("End CPU kthread@rcu_wait");
                rcu_wait(*workp != 0 || kthread_should_stop());
+               trace_rcu_utilization("Start CPU kthread@rcu_wait");
                local_bh_disable();
                if (rcu_cpu_kthread_should_stop(cpu)) {
                        local_bh_enable();
@@ -1513,11 +1522,14 @@ static int rcu_cpu_kthread(void *arg)
                        spincnt = 0;
                if (spincnt > 10) {
                        *statusp = RCU_KTHREAD_YIELDING;
+                       trace_rcu_utilization("End CPU kthread@rcu_yield");
                        rcu_yield(rcu_cpu_kthread_timer, (unsigned long)cpu);
+                       trace_rcu_utilization("Start CPU kthread@rcu_yield");
                        spincnt = 0;
                }
        }
        *statusp = RCU_KTHREAD_STOPPED;
+       trace_rcu_utilization("End CPU kthread@term");
        return 0;
 }