perf tools: Add cpu to struct thread

Tools may wish to track on which cpu a thread is running.  Add 'cpu' to
struct thread for that purpose.

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

E.g: Intel PT decoding uses sched_switch events to determine which task
is running on which cpu.  The Intel PT data comes straight from the
hardware which doesn't know about linux threads.

Signed-off-by: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: ahunter6

tools/perf/util/thread.c

@@ -34,6 +34,7 @@ struct thread *thread__new(pid_t pid, pid_t tid)
 		thread->pid_ = pid;
 		thread->tid = tid;
 		thread->ppid = -1;
+		thread->cpu = -1;
 		INIT_LIST_HEAD(&thread->comm_list);
 
 		comm_str = malloc(32);

tools/perf/util/thread.h

@@ -17,6 +17,7 @@ struct thread {
 	pid_t			pid_; /* Not all tools update this */
 	pid_t			tid;
 	pid_t			ppid;
+	int			cpu;
 	char			shortname[3];
 	bool			comm_set;
 	bool			dead; /* if set thread has exited */