util: add a script for testing checkpointing

See comments in util/checkpoint-tester.py for details.

configs/common/Simulation.py

@@ -292,6 +292,16 @@ def run(options, root, testsys, cpu_class):
     num_checkpoints = 0
     exit_cause = ''
 
+    # If we're taking and restoring checkpoints, use checkpoint_dir
+    # option only for finding the checkpoints to restore from.  This
+    # lets us test checkpointing by restoring from one set of
+    # checkpoints, generating a second set, and then comparing them.
+    if options.take_checkpoints and options.checkpoint_restore:
+        if m5.options.outdir:
+            cptdir = m5.options.outdir
+        else:
+            cptdir = getcwd()
+
     # Checkpoints being taken via the command line at <when> and at
     # subsequent periods of <period>.  Checkpoint instructions
     # received from the benchmark running are ignored and skipped in

util/checkpoint-tester.py

@@ -0,0 +1,135 @@
+#! /usr/bin/env python
+
+# Copyright (c) 2010 Advanced Micro Devices, Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met: redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer;
+# redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution;
+# neither the name of the copyright holders nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# Author: Steve Reinhardt
+#
+
+# Basic test script for checkpointing.
+#
+# Given an M5 command and an interval (in ticks), this script will:
+# 1. Run the command, dumping periodic checkpoints at the given interval.
+# 2. Rerun the command for each pair of adjacent checkpoints:
+#    a. Restore from checkpoint N
+#    b. Run until the timestamp of checkpoint N+1
+#    c. Dump a checkpoint and end the simulation
+#    d. Diff the new checkpoint with the original checkpoint N+1
+#
+# Note that '--' must be used to separate the script options from the
+# M5 command line.
+#
+# Caveats:
+#
+# - This script relies on the checkpoint options implemented in
+#   configs/common/Simulation.py, so it works with commands based on
+#   the se.py and fs.py scripts in configs/example, but does not work
+#   directly with the existing regression tests.
+# - Interleaving simulator and program output can cause discrepancies
+#   in the file position checkpoint information since different runs
+#   have different amount of simulator output.
+# - Probably lots more issues we don't even know about yet.
+#
+# Examples:
+#
+# util/checkpoint-tester.py -i 400000 -- build/ALPHA_SE/m5.opt \
+#      configs/example/se.py -c tests/test-progs/hello/bin/alpha/tru64/hello \
+#      --output=progout --errout=progerr
+#
+# util/checkpoint-tester.py -i 200000000000 -- build/ALPHA_FS/m5.opt \
+#      configs/example/fs.py --script tests/halt.sh
+#
+
+
+import os, sys, re
+import subprocess
+import optparse
+
+parser = optparse.OptionParser()
+
+parser.add_option('-i', '--interval', type='int')
+parser.add_option('-d', '--directory', default='checkpoint-test')
+
+(options, args) = parser.parse_args()
+
+interval = options.interval
+
+if os.path.exists(options.directory):
+    print 'Error: test directory', options.directory, 'exists'
+    print '       Tester needs to create directory from scratch'
+    sys.exit(1)
+
+top_dir = options.directory
+os.mkdir(top_dir)
+
+cmd_echo = open(os.path.join(top_dir, 'command'), 'w')
+print >>cmd_echo, ' '.join(sys.argv)
+cmd_echo.close()
+
+m5_binary = args[0]
+
+options = args[1:]
+
+initial_args = ['--take-checkpoints', '%d,%d' % (interval, interval)]
+
+cptdir = os.path.join(top_dir, 'm5out')
+
+print '===> Running initial simulation.'
+subprocess.call([m5_binary] + ['-red', cptdir] + options + initial_args)
+
+dirs = os.listdir(cptdir)
+expr = re.compile('cpt\.([0-9]*)')
+cpts = []
+for dir in dirs:
+    match = expr.match(dir)
+    if match:
+        cpts.append(int(match.group(1)))
+
+cpts.sort()
+        
+# We test by loading checkpoint N, simulating to (and dumping at)
+# checkpoint N+1, then comparing the resulting checkpoint with the
+# original checkpoint N+1.  Thus the number of tests we can run is one
+# less than tha number of checkpoints.
+for i in range(1, len(cpts)):
+    print '===> Running test %d of %d.' % (i, len(cpts)-1)
+    mydir = os.path.join(top_dir, 'test.%d' % i)
+    subprocess.call([m5_binary] + ['-red', mydir] + options + initial_args +
+                    ['--max-checkpoints' , '1', '--checkpoint-dir', cptdir,
+                     '--checkpoint-restore', str(i)])
+    cpt_name = 'cpt.%d' % cpts[i]
+    diff_name = os.path.join(mydir, 'diffout')
+    diffout = open(diff_name, 'w')
+    subprocess.call(['diff', '-ru', '-I', '^##.*',
+                     '%s/%s' % (cptdir, cpt_name),
+                     '%s/%s' % (mydir, cpt_name)], stdout=diffout)
+    diffout.close()
+    # print out the diff
+    diffout = open(diff_name)
+    print diffout.read(),
+    diffout.close()
+
+