rcu: Track rcu_nocb_kthread()'s sleeping and awakening

[platform/adaptation/renesas_rcar/renesas_kernel.git] / include / trace / events / rcu.h

diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h
index ee2376c..a087d82 100644 (file)
--- a/include/trace/events/rcu.h
+++ b/include/trace/events/rcu.h
@@ -39,15 +39,26 @@ TRACE_EVENT(rcu_utilization,
 #if defined(CONFIG_TREE_RCU) || defined(CONFIG_TREE_PREEMPT_RCU)
 
 /*
- * Tracepoint for grace-period events: starting and ending a grace
- * period ("start" and "end", respectively), a CPU noting the start
- * of a new grace period or the end of an old grace period ("cpustart"
- * and "cpuend", respectively), a CPU passing through a quiescent
- * state ("cpuqs"), a CPU coming online or going offline ("cpuonl"
- * and "cpuofl", respectively), a CPU being kicked for being too
- * long in dyntick-idle mode ("kick"), a CPU accelerating its new
- * callbacks to RCU_NEXT_READY_TAIL ("AccReadyCB"), and a CPU
- * accelerating its new callbacks to RCU_WAIT_TAIL ("AccWaitCB").
+ * Tracepoint for grace-period events.  Takes a string identifying the
+ * RCU flavor, the grace-period number, and a string identifying the
+ * grace-period-related event as follows:
+ *
+ *     "AccReadyCB": CPU acclerates new callbacks to RCU_NEXT_READY_TAIL.
+ *     "AccWaitCB": CPU accelerates new callbacks to RCU_WAIT_TAIL.
+ *     "newreq": Request a new grace period.
+ *     "start": Start a grace period.
+ *     "cpustart": CPU first notices a grace-period start.
+ *     "cpuqs": CPU passes through a quiescent state.
+ *     "cpuonl": CPU comes online.
+ *     "cpuofl": CPU goes offline.
+ *     "reqwait": GP kthread sleeps waiting for grace-period request.
+ *     "reqwaitsig": GP kthread awakened by signal from reqwait state.
+ *     "fqswait": GP kthread waiting until time to force quiescent states.
+ *     "fqsstart": GP kthread starts forcing quiescent states.
+ *     "fqsend": GP kthread done forcing quiescent states.
+ *     "fqswaitsig": GP kthread awakened by signal from fqswait state.
+ *     "end": End a grace period.
+ *     "cpuend": CPU first notices a grace-period end.
  */
 TRACE_EVENT(rcu_grace_period,
 
@@ -161,6 +172,46 @@ TRACE_EVENT(rcu_grace_period_init,
 );
 
 /*
+ * Tracepoint for RCU no-CBs CPU callback handoffs.  This event is intended
+ * to assist debugging of these handoffs.
+ *
+ * The first argument is the name of the RCU flavor, and the second is
+ * the number of the offloaded CPU are extracted.  The third and final
+ * argument is a string as follows:
+ *
+ *     "WakeEmpty": Wake rcuo kthread, first CB to empty list.
+ *     "WakeOvf": Wake rcuo kthread, CB list is huge.
+ *     "WakeNot": Don't wake rcuo kthread.
+ *     "WakeNotPoll": Don't wake rcuo kthread because it is polling.
+ *     "Poll": Start of new polling cycle for rcu_nocb_poll.
+ *     "Sleep": Sleep waiting for CBs for !rcu_nocb_poll.
+ *     "WokeEmpty": rcuo kthread woke to find empty list.
+ *     "WokeNonEmpty": rcuo kthread woke to find non-empty list.
+ *     "WaitQueue": Enqueue partially done, timed wait for it to complete.
+ *     "WokeQueue": Partial enqueue now complete.
+ */
+TRACE_EVENT(rcu_nocb_wake,
+
+       TP_PROTO(const char *rcuname, int cpu, const char *reason),
+
+       TP_ARGS(rcuname, cpu, reason),
+
+       TP_STRUCT__entry(
+               __field(const char *, rcuname)
+               __field(int, cpu)
+               __field(const char *, reason)
+       ),
+
+       TP_fast_assign(
+               __entry->rcuname = rcuname;
+               __entry->cpu = cpu;
+               __entry->reason = reason;
+       ),
+
+       TP_printk("%s %d %s", __entry->rcuname, __entry->cpu, __entry->reason)
+);
+
+/*
  * Tracepoint for tasks blocking within preemptible-RCU read-side
  * critical sections.  Track the type of RCU (which one day might
  * include SRCU), the grace-period number that the task is blocking
@@ -656,6 +707,7 @@ TRACE_EVENT(rcu_barrier,
 #define trace_rcu_future_grace_period(rcuname, gpnum, completed, c, \
                                      level, grplo, grphi, event) \
                                      do { } while (0)
+#define trace_rcu_nocb_wake(rcuname, cpu, reason) do { } while (0)
 #define trace_rcu_preempt_task(rcuname, pid, gpnum) do { } while (0)
 #define trace_rcu_unlock_preempted_task(rcuname, gpnum, pid) do { } while (0)
 #define trace_rcu_quiescent_state_report(rcuname, gpnum, mask, qsmask, level, \