Merge branch 'rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

Pull RCU updates from Paul E. McKenney.

Major changes:

" 1.	Update RCU documentation.  These were posted to LKML at
	http://article.gmane.org/gmane.linux.kernel/1566994.

  2.	Miscellaneous fixes.  These were posted to LKML at
	http://article.gmane.org/gmane.linux.kernel/1567027.

  3.	Grace-period-related changes, primarily to aid in debugging,
	inspired by a -rt debugging session.  These were posted to
	LKML at http://article.gmane.org/gmane.linux.kernel/1567076.

  4.	Idle entry/exit changes, primarily to address issues located
	by Tibor Billes.  These were posted to LKML at
	http://article.gmane.org/gmane.linux.kernel/1567096.

  5.	Code reorganization moving RCU's source files from kernel
	to kernel/rcu.  This was posted to LKML at
	http://article.gmane.org/gmane.linux.kernel/1577344."

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 66 insertions, 14 deletions

diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h
index ee2376cfaab3..aca382266411 100644
--- 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
@@ -540,17 +591,17 @@ TRACE_EVENT(rcu_invoke_kfree_callback,
 TRACE_EVENT(rcu_batch_end,
 
         TP_PROTO(const char *rcuname, int callbacks_invoked,
-                 bool cb, bool nr, bool iit, bool risk),
+                 char cb, char nr, char iit, char risk),
 
         TP_ARGS(rcuname, callbacks_invoked, cb, nr, iit, risk),
 
         TP_STRUCT__entry(
                 __field(const char *, rcuname)
                 __field(int, callbacks_invoked)
-                __field(bool, cb)
-                __field(bool, nr)
-                __field(bool, iit)
-                __field(bool, risk)
+                __field(char, cb)
+                __field(char, nr)
+                __field(char, iit)
+                __field(char, risk)
         ),
 
         TP_fast_assign(
@@ -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, \