Merge remote branch 'cros/upstream' into tempbranch

client/tests/tracing_microbenchmark/tracers.py

Index: client/tests/tracing_microbenchmark/tracers.py
diff --git a/client/tests/tracing_microbenchmark/tracers.py b/client/tests/tracing_microbenchmark/tracers.py
new file mode 100644
index 0000000000000000000000000000000000000000..bdd5194de0ccfa8caf52f0acecb5f961378fd880
--- /dev/null
+++ b/client/tests/tracing_microbenchmark/tracers.py
@@ -0,0 +1,60 @@
+import os
+from autotest_lib.client.bin import utils
+
+import base_tracer
+try:
+    from site_tracers import *
+except ImportError:
+    pass
+
+
+off = base_tracer.Tracer
+
+
+class ftrace(base_tracer.Tracer):
+
+    mountpoint = '/sys/kernel/debug'
+    tracing_dir = os.path.join(mountpoint, 'tracing')
+
+    def warmup(self, buffer_size_kb):
+        if not os.path.exists(self.tracing_dir):
+            utils.system('mount -t debugfs debugfs %s' % self.mountpoint)
+
+        # ensure clean state:
+        self.trace_config('tracing_enabled', '0')
+        self.trace_config('current_tracer', 'nop')
+        self.trace_config('events/enable', '0')
+        self.trace_config('trace', '')
+        # set ring buffer size:
+        self.trace_config('buffer_size_kb', str(buffer_size_kb))
+        # enable tracepoints:
+        self.trace_config('events/syscalls/sys_enter_getuid/enable', '1')
+
+    def cleanup(self):
+        # reset ring buffer size:
+        self.trace_config('buffer_size_kb', '1408')
+        # disable tracepoints:
+        self.trace_config('events/enable', '0')
+
+    def start_tracing(self):
+        self.trace_config('tracing_enabled', '1')
+
+    def stop_tracing(self):
+        self.trace_config('tracing_enabled', '0')
+
+    def reset_tracing(self):
+        self.trace_config('trace', '')
+
+    def gather_stats(self, results):
+        per_cpu = os.path.join(self.tracing_dir, 'per_cpu')
+        for cpu in os.listdir(per_cpu):
+            cpu_stats = os.path.join(per_cpu, cpu, 'stats')
+            for line in utils.read_file(cpu_stats).splitlines():
+                key, val = line.split(': ')
+                key = key.replace(' ', '_')
+                val = int(val)
+                cpu_key = '%s_%s' % (cpu, key)
+                total_key = 'total_' + key
+                results[cpu_key] = val
+                results[total_key] = (results.get(total_key, 0) + 
+                                      results[cpu_key])