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authorPaul E. McKenney <paul.mckenney@linaro.org>2011-06-17 15:53:19 -0700
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2011-09-28 21:38:12 -0700
commit29c00b4a1d9e277786120032aa8364631820d863 (patch)
tree23bf0c8cdb5268ef92ef9ed007639705e922b1b0 /include/trace
parent9d68197c05201d8edc70d58bd1d5dad05d8455e8 (diff)
rcu: Add event-tracing for RCU callback invocation
There was recently some controversy about the overhead of invoking RCU callbacks. Add TRACE_EVENT()s to obtain fine-grained timings for the start and stop of a batch of callbacks and also for each callback invoked. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'include/trace')
-rw-r--r--include/trace/events/rcu.h98
1 files changed, 98 insertions, 0 deletions
diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h
new file mode 100644
index 000000000000..db3f6e9e63e6
--- /dev/null
+++ b/include/trace/events/rcu.h
@@ -0,0 +1,98 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM rcu
+
+#if !defined(_TRACE_RCU_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_RCU_H
+
+#include <linux/tracepoint.h>
+
+/*
+ * Tracepoint for calling rcu_do_batch, performed to start callback invocation:
+ */
+TRACE_EVENT(rcu_batch_start,
+
+ TP_PROTO(long callbacks_ready, int blimit),
+
+ TP_ARGS(callbacks_ready, blimit),
+
+ TP_STRUCT__entry(
+ __field( long, callbacks_ready )
+ __field( int, blimit )
+ ),
+
+ TP_fast_assign(
+ __entry->callbacks_ready = callbacks_ready;
+ __entry->blimit = blimit;
+ ),
+
+ TP_printk("CBs=%ld bl=%d", __entry->callbacks_ready, __entry->blimit)
+);
+
+/*
+ * Tracepoint for the invocation of a single RCU callback
+ */
+TRACE_EVENT(rcu_invoke_callback,
+
+ TP_PROTO(struct rcu_head *rhp),
+
+ TP_ARGS(rhp),
+
+ TP_STRUCT__entry(
+ __field( void *, rhp )
+ __field( void *, func )
+ ),
+
+ TP_fast_assign(
+ __entry->rhp = rhp;
+ __entry->func = rhp->func;
+ ),
+
+ TP_printk("rhp=%p func=%pf", __entry->rhp, __entry->func)
+);
+
+/*
+ * Tracepoint for the invocation of a single RCU kfree callback
+ */
+TRACE_EVENT(rcu_invoke_kfree_callback,
+
+ TP_PROTO(struct rcu_head *rhp, unsigned long offset),
+
+ TP_ARGS(rhp, offset),
+
+ TP_STRUCT__entry(
+ __field(void *, rhp )
+ __field(unsigned long, offset )
+ ),
+
+ TP_fast_assign(
+ __entry->rhp = rhp;
+ __entry->offset = offset;
+ ),
+
+ TP_printk("rhp=%p func=%ld", __entry->rhp, __entry->offset)
+);
+
+/*
+ * Tracepoint for leaving rcu_do_batch, performed after callback invocation:
+ */
+TRACE_EVENT(rcu_batch_end,
+
+ TP_PROTO(int callbacks_invoked),
+
+ TP_ARGS(callbacks_invoked),
+
+ TP_STRUCT__entry(
+ __field( int, callbacks_invoked )
+ ),
+
+ TP_fast_assign(
+ __entry->callbacks_invoked = callbacks_invoked;
+ ),
+
+ TP_printk("CBs-invoked=%d", __entry->callbacks_invoked)
+);
+
+#endif /* _TRACE_RCU_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>