diff --git a/tests/configs/base_config.py b/tests/configs/base_config.py
index e099633..2bed5f6 100644
--- a/tests/configs/base_config.py
+++ b/tests/configs/base_config.py
@@ -288,7 +288,7 @@
                                            response_latency = 20,
                                            tgts_per_mshr = 8)
                           for r in system.mem_ranges]
-            for i in xrange(len(system.physmem)):
+            for i in range(len(system.physmem)):
                 system.physmem[i].port = system.llc[i].mem_side
                 system.llc[i].cpu_side = system.membus.master
 
diff --git a/tests/configs/gpu-ruby.py b/tests/configs/gpu-ruby.py
index e846dba..155775a 100644
--- a/tests/configs/gpu-ruby.py
+++ b/tests/configs/gpu-ruby.py
@@ -197,7 +197,7 @@
 
 # List of compute units; one GPU can have multiple compute units
 compute_units = []
-for i in xrange(n_cu):
+for i in range(n_cu):
     compute_units.append(ComputeUnit(cu_id = i, perLaneTLB = per_lane,
                                      num_SIMDs = options.simds_per_cu,
                                      wfSize = options.wf_size,
@@ -227,8 +227,8 @@
                                               options.ldsBankConflictPenalty)))
     wavefronts = []
     vrfs = []
-    for j in xrange(options.simds_per_cu):
-        for k in xrange(shader.n_wf):
+    for j in range(options.simds_per_cu):
+        for k in range(int(shader.n_wf)):
             wavefronts.append(Wavefront(simdId = j, wf_slot_id = k))
         vrfs.append(VectorRegisterFile(simd_id=j,
                               num_regs_per_simd=options.vreg_file_size))
@@ -308,15 +308,15 @@
 gpu_port_idx = gpu_port_idx - options.num_cp * 2
 
 wavefront_size = options.wf_size
-for i in xrange(n_cu):
+for i in range(n_cu):
     # The pipeline issues wavefront_size number of uncoalesced requests
     # in one GPU issue cycle. Hence wavefront_size mem ports.
-    for j in xrange(wavefront_size):
+    for j in range(wavefront_size):
         system.cpu[shader_idx].CUs[i].memory_port[j] = \
                   system.ruby._cpu_ports[gpu_port_idx].slave[j]
     gpu_port_idx += 1
 
-for i in xrange(n_cu):
+for i in range(n_cu):
     if i > 0 and not i % options.cu_per_sqc:
         gpu_port_idx += 1
     system.cpu[shader_idx].CUs[i].sqc_port = \
diff --git a/tests/configs/memtest-filter.py b/tests/configs/memtest-filter.py
index 90ad042..56297d2 100644
--- a/tests/configs/memtest-filter.py
+++ b/tests/configs/memtest-filter.py
@@ -33,7 +33,7 @@
 
 #MAX CORES IS 8 with the fals sharing method
 nb_cores = 8
-cpus = [ MemTest() for i in xrange(nb_cores) ]
+cpus = [ MemTest() for i in range(nb_cores) ]
 
 # system simulated
 system = System(cpu = cpus,
diff --git a/tests/configs/memtest-ruby.py b/tests/configs/memtest-ruby.py
index 9cf92af..5947c80 100644
--- a/tests/configs/memtest-ruby.py
+++ b/tests/configs/memtest-ruby.py
@@ -66,7 +66,7 @@
 # ruby does not support atomic, functional, or uncacheable accesses
 cpus = [ MemTest(percent_functional=50,
                  percent_uncacheable=0, suppress_func_warnings=True) \
-         for i in xrange(nb_cores) ]
+         for i in range(nb_cores) ]
 
 # overwrite options.num_cpus with the nb_cores value
 options.num_cpus = nb_cores
diff --git a/tests/configs/memtest.py b/tests/configs/memtest.py
index db7a5ef..959ec4e 100644
--- a/tests/configs/memtest.py
+++ b/tests/configs/memtest.py
@@ -33,7 +33,7 @@
 
 #MAX CORES IS 8 with the fals sharing method
 nb_cores = 8
-cpus = [ MemTest() for i in xrange(nb_cores) ]
+cpus = [ MemTest() for i in range(nb_cores) ]
 
 # system simulated
 system = System(cpu = cpus,
diff --git a/tests/configs/o3-timing-mp-ruby.py b/tests/configs/o3-timing-mp-ruby.py
index 9248b08..90319d1 100644
--- a/tests/configs/o3-timing-mp-ruby.py
+++ b/tests/configs/o3-timing-mp-ruby.py
@@ -30,7 +30,7 @@
 from m5.objects import *
 
 nb_cores = 4
-cpus = [ DerivO3CPU(cpu_id=i) for i in xrange(nb_cores) ]
+cpus = [ DerivO3CPU(cpu_id=i) for i in range(nb_cores) ]
 
 import ruby_config
 ruby_memory = ruby_config.generate("TwoLevel_SplitL1UnifiedL2.rb", nb_cores)
diff --git a/tests/configs/pc-simple-timing-ruby.py b/tests/configs/pc-simple-timing-ruby.py
index 19c38dc..18c9909 100644
--- a/tests/configs/pc-simple-timing-ruby.py
+++ b/tests/configs/pc-simple-timing-ruby.py
@@ -63,7 +63,7 @@
 system.cpu_clk_domain = SrcClockDomain(clock = '2GHz',
                                        voltage_domain = system.voltage_domain)
 system.cpu = [TimingSimpleCPU(cpu_id=i, clk_domain = system.cpu_clk_domain)
-              for i in xrange(options.num_cpus)]
+              for i in range(options.num_cpus)]
 
 Ruby.create_system(options, True, system, system.iobus, system._dma_ports)
 
diff --git a/tests/configs/simple-atomic-mp-ruby.py b/tests/configs/simple-atomic-mp-ruby.py
index e435907..52cba7d 100644
--- a/tests/configs/simple-atomic-mp-ruby.py
+++ b/tests/configs/simple-atomic-mp-ruby.py
@@ -30,7 +30,7 @@
 from m5.objects import *
 
 nb_cores = 4
-cpus = [ AtomicSimpleCPU(cpu_id=i) for i in xrange(nb_cores) ]
+cpus = [ AtomicSimpleCPU(cpu_id=i) for i in range(nb_cores) ]
 
 import ruby_config
 ruby_memory = ruby_config.generate("TwoLevel_SplitL1UnifiedL2.rb", nb_cores)
diff --git a/tests/configs/simple-timing-mp-ruby.py b/tests/configs/simple-timing-mp-ruby.py
index 248d046..52d7df9 100644
--- a/tests/configs/simple-timing-mp-ruby.py
+++ b/tests/configs/simple-timing-mp-ruby.py
@@ -59,7 +59,7 @@
 options.l3_assoc=2
 
 nb_cores = 4
-cpus = [ TimingSimpleCPU(cpu_id=i) for i in xrange(nb_cores) ]
+cpus = [ TimingSimpleCPU(cpu_id=i) for i in range(nb_cores) ]
 
 # overwrite the num_cpus to equal nb_cores
 options.num_cpus = nb_cores
diff --git a/tests/configs/t1000-simple-atomic.py b/tests/configs/t1000-simple-atomic.py
index 0d971a0..ea906b3 100644
--- a/tests/configs/t1000-simple-atomic.py
+++ b/tests/configs/t1000-simple-atomic.py
@@ -51,7 +51,7 @@
 # the physmem name to avoid bumping all the reference stats
 system.physmem = [SimpleMemory(range = r)
                   for r in system.mem_ranges]
-for i in xrange(len(system.physmem)):
+for i in range(len(system.physmem)):
     system.physmem[i].port = system.membus.master
 
 root = Root(full_system=True, system=system)
diff --git a/tests/legacy-configs/run.py b/tests/legacy-configs/run.py
index 3eac490..47b5ab7 100644
--- a/tests/legacy-configs/run.py
+++ b/tests/legacy-configs/run.py
@@ -85,7 +85,7 @@
 executable = args.executable
 
 for config in args.config:
-    execfile(config)
+    exec(compile(open(config).read(), config, 'exec'))
 
 # Initialize all CPUs in a system
 def initCPUs(sys):
diff --git a/tests/run.py b/tests/run.py
index 93ea82e..6e4b453 100644
--- a/tests/run.py
+++ b/tests/run.py
@@ -209,7 +209,9 @@
 # for ruby configurations, remove the protocol name from the test filename
 if re.search('-ruby', test_filename):
     test_filename = test_filename.split('-ruby')[0]+'-ruby'
-execfile(joinpath(tests_root, 'configs', test_filename + '.py'))
+exec(compile( \
+    open(joinpath(tests_root, 'configs', test_filename + '.py')).read(), \
+    joinpath(tests_root, 'configs', test_filename + '.py'), 'exec'))
 
 # set default maxtick... script can override
 # -1 means run forever
@@ -217,7 +219,9 @@
 
 # tweak configuration for specific test
 sys.path.append(joinpath(tests_root, category, mode, name))
-execfile(joinpath(tests_root, category, mode, name, 'test.py'))
+exec(compile( \
+    open(joinpath(tests_root, category, mode, name, 'test.py')).read(), \
+    joinpath(tests_root, category, mode, name, 'test.py'), 'exec'))
 
 # Initialize all CPUs in a system
 def initCPUs(sys):