torture: Trace long read-side delays

Although rcutorture will occasionally do a 50-millisecond grace-period delay, these delays are quite rare. And rightly so, because otherwise the read rate would be quite low. Thie means that it can be important to identify whether or not a given run contained a long-delay read. This commit therefore inserts a trace_rcu_torture_read() event to flag runs containing long delays.

Paul E. McKenney committed 10 years ago

Commit d0af39e1 parent f2151a02 files · +14 −2Browse files

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include/trace/events/rcu.h+4−1

@@ -698,7 +698,10 @@ TRACE_EVENT(rcu_batch_end, · 697 unmodified lines
698	698	/*
699	699	* Tracepoint for rcutorture readers. The first argument is the name
700	700	* of the RCU flavor from rcutorture's viewpoint and the second argument
701		− * is the callback address.
	701	+ * is the callback address. The third argument is the start time in
	702	+ * seconds, and the last two arguments are the grace period numbers
	703	+ * at the beginning and end of the read, respectively. Note that the
	704	+ * callback address can be NULL.
702	705	*/
703	706	TRACE_EVENT(rcu_torture_read,
704	707