perf machine: Add ability to record the current tid for each cpu

Add an array to struct machine to store the current tid running on each
cpu.

Add machine functions to get / set the tid for a cpu.

This will be used to determine the tid when decoding a per-cpu
Instruction Trace.

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/1406035081-14301-17-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h
index c8c74a1..8771d0c 100644
--- a/tools/perf/util/machine.h
+++ b/tools/perf/util/machine.h
@@ -33,6 +33,7 @@
 	struct map_groups kmaps;
 	struct map	  *vmlinux_maps[MAP__NR_TYPES];
 	symbol_filter_t	  symbol_filter;
+	pid_t		  *current_tid;
 };
 
 static inline
@@ -191,4 +192,8 @@
 					     perf_event__process, data_mmap);
 }
 
+pid_t machine__get_current_tid(struct machine *machine, int cpu);
+int machine__set_current_tid(struct machine *machine, int cpu, pid_t pid,
+			     pid_t tid);
+
 #endif /* __PERF_MACHINE_H */