diff -r 8a9b86071c15 perf.py
--- a/perf.py	Fri Dec 04 14:15:34 2015 -0800
+++ b/perf.py	Wed Feb 03 10:22:02 2016 +0200
@@ -88,6 +88,24 @@
 info = logging.info
 
 
+def have_taskset():
+    """Check if we are running on Linux and if the taskset command is
+    available. Taskset specifies CPU affinity for a given workload,
+    meaning that we can run the benchmarks on a given core to minimize
+    run to run variation.
+    """
+    if (platform.system() == "Linux"):
+        command = ["taskset", "-V"]
+        subproc = subprocess.Popen(command,
+                                   stdout=subprocess.PIPE,
+                                   stderr=subprocess.PIPE)
+        out, err = subproc.communicate()
+        if subproc.returncode != 0:
+            return False
+        else:
+            return True
+
+
 def interpreter_version(python, _cache={}):
     """Return the interpreter version for the given Python interpreter.
     *python* is the base command (as a list) to execute the interpreter.
@@ -2557,6 +2575,12 @@
                             " Unladen Swallow binaries. This is useful for"
                             " examining many benchmarks for optimization"
                             " effects."))
+    parser.add_option("--affinity", metavar="CPU_MASK", default=None,
+                      help=("Specify CPU affinity for benchmark runs. This way,"
+                            " benchmarks can be forced to run on a given CPU to"
+                            " minimize run to run variation. This is"
+                            " implemented on Linux and uses the taskset"
+                            " command."))
 
 
     options, args = parser.parse_args(argv)
@@ -2575,6 +2599,10 @@
     base_cmd_prefix = [base] + base_args
     changed_cmd_prefix = [changed] + changed_args
 
+    if options.affinity and have_taskset():
+        base_cmd_prefix = ["taskset", options.affinity] + base_cmd_prefix
+        changed_cmd_prefix = ["taskset", options.affinity] + changed_cmd_prefix
+
     logging.basicConfig(level=logging.INFO)
 
     if options.track_memory: