perf bench: Add memcpy() benchmark

'perf bench mem memcpy' is a benchmark suite for measuring memcpy()
performance.

Example on a Intel(R) Core(TM)2 Duo CPU E6850 @ 3.00GHz:

| % perf bench mem memcpy -l 1GB
| # Running mem/memcpy benchmark...
| # Copying 1MB Bytes from 0xb7d98008 to 0xb7e99008 ...
|
|     726.216412 MB/Sec

Signed-off-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1258471212-30281-1-git-send-email-mitake@dcl.info.waseda.ac.jp>
[ v2: updated changelog, clarified history of builtin-bench.c ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>

tools/perf/builtin-bench.c

@@ -12,6 +12,7 @@
  *
  * Available subsystem list:
  *  sched ... scheduler and IPC mechanism
+ *  mem   ... memory access performance
  *
  */
 
@@ -43,6 +44,15 @@ static struct bench_suite sched_suites[] = {
 	  NULL                  }
 };
 
+static struct bench_suite mem_suites[] = {
+	{ "memcpy",
+	  "Simple memory copy in various ways",
+	  bench_mem_memcpy },
+	{ NULL,
+	  NULL,
+	  NULL             }
+};
+
 struct bench_subsys {
 	const char *name;
 	const char *summary;
@@ -53,9 +63,12 @@ static struct bench_subsys subsystems[] = {
 	{ "sched",
 	  "scheduler and IPC mechanism",
 	  sched_suites },
+	{ "mem",
+	  "memory access performance",
+	  mem_suites },
 	{ NULL,
 	  NULL,
-	  NULL         }
+	  NULL       }
 };
 
 static void dump_suites(int subsys_index)