Index: lit.cfg
===================================================================
--- lit.cfg
+++ lit.cfg
@@ -145,6 +145,13 @@
     new_commandline = " ".join(map(quote, runsafely_prefix + tokens))
     return new_commandline
 
+def wrapScriptInRunSafely(script, outfile):
+    adjusted_script = []
+    for line in script:
+        line = prepareRunSafely(config, line, outfile)
+        adjusted_script.append(line)
+    return adjusted_script
+
 class TestSuiteTest(FileBasedTest):
     def __init__(self):
         super(TestSuiteTest, self).__init__()
@@ -169,11 +176,19 @@
         runscript = applySubstitutions(runscript, substitutions)
         verifyscript = applySubstitutions(verifyscript, substitutions)
 
-        adjusted_runscript = []
-        for line in runscript:
-            line = prepareRunSafely(config, line, outfile)
-            adjusted_runscript.append(line)
-        runscript = adjusted_runscript
+        if litConfig.params.get('profile') == 'perf':
+            # wrap linux perf command to do profiling
+            profilefile = tmpBase + ".perf_data"
+            profilescript=[]
+            for line in runscript:
+                profilescript.append(
+                    ' '.join(
+                        ['perf record -e cycles,cache-misses,branch-misses -o',
+                          profilefile, line]))
+            profilescript = wrapScriptInRunSafely(profilescript,
+                                                  outfile=tmpBase+".perf.out")
+
+        runscript = wrapScriptInRunSafely(runscript, outfile)
 
         # Create the output directory if it does not already exist.
         lit.util.mkdir_p(os.path.dirname(tmpBase))
@@ -203,6 +218,10 @@
             except IOError:
                 pass
 
+        if litConfig.params.get('profile') == 'perf':
+            res = runScript(test, litConfig, profilescript, tmpBase)
+            out, err, exitCode, timeoutInfo = res
+
         # Run verification script (the "VERIFY:" part)
         if len(verifyscript) > 0:
             res = runScript(test, litConfig, verifyscript, tmpBase)