perf session: Flag if the event stream is entirely in memory

Flag if the event stream is a file that has been mmapped in one go.

This is useful, for example, if a tool needs to keep an event for later
reference.  If the new flag is set, a pointer to the event can be
retained, otherwise the event must be copied.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1405332185-4050-28-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index 3140f8a..0321013 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -36,6 +36,9 @@
 	struct trace_event	tevent;
 	struct events_stats	stats;
 	bool			repipe;
+	bool			one_mmap;
+	void			*one_mmap_addr;
+	u64			one_mmap_offset;
 	struct ordered_samples	ordered_samples;
 	struct perf_data_file	*file;
 };