gem5/util/cpt_upgrader.py
Curtis Dunham 87b9da2df4 sim: tag-based checkpoint versioning
This commit addresses gem5 checkpoints' linear versioning bottleneck.
Since development is distributed across many private trees, there exists
a sort of 'race' for checkpoint version numbers: internally a checkpoint
version may be used but then resynchronizing with the external tree causes
a conflict on that version.  This change replaces the linear version number
with a set of unique strings called tags.  Now the only conflicts that can
arise are of tag names, where collisions are much easier to avoid.

The checkpoint upgrader (util/cpt_upgrader.py) upgrades the version
representation, as one would expect. Each tag version implements its
upgrader code in a python file in the util/cpt_upgraders directory
rather than adding a function to the upgrader script itself.

The version tags are stored in the 'Globals' section rather than 'root'
(as the version was previously) because 'Globals' gets unserialized
first and can provide a warning before any other unserialization errors
can occur.
2015-09-02 15:23:30 -05:00

266 lines
9.8 KiB
Python
Executable file

#!/usr/bin/env python
# Copyright (c) 2012-2013,2015 ARM Limited
# All rights reserved
#
# The license below extends only to copyright in the software and shall
# not be construed as granting a license to any other intellectual
# property including but not limited to intellectual property relating
# to a hardware implementation of the functionality of the software
# licensed hereunder. You may use the software subject to the license
# terms below provided that you ensure that this notice is replicated
# unmodified and in its entirety in all distributions of the software,
# modified or unmodified, in source code or in binary form.
#
# 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.
#
# Authors: Ali Saidi
# Curtis Dunham
#
# This python code is used to migrate checkpoints that were created in one
# version of the simulator to newer version. As features are added or bugs are
# fixed some of the state that needs to be checkpointed can change. If you have
# many historic checkpoints that you use, manually editing them to fix them is
# both time consuming and error-prone.
# This script provides a way to migrate checkpoints to the newer repository in
# a programmatic way. It can be imported into another script or used on the
# command line. From the command line the script will either migrate every
# checkpoint it finds recursively (-r option) or a single checkpoint. When a
# change is made to the gem5 repository that breaks previous checkpoints an
# upgrade() method should be implemented in its own .py file and placed in
# src/util/cpt_upgraders/. For each upgrader whose tag is not present in
# the checkpoint tag list, the upgrade() method will be run, passing in a
# ConfigParser object which contains the open file. As these operations can
# be isa specific the method can verify the isa and use regexes to find the
# correct sections that need to be updated.
import ConfigParser
import glob, types, sys, os
import os.path as osp
verbose_print = False
def verboseprint(*args):
if not verbose_print:
return
for arg in args:
print arg,
print
class Upgrader:
tag_set = set()
by_tag = {}
legacy = {}
def __init__(self, filename):
self.filename = filename
execfile(filename, {}, self.__dict__)
if not hasattr(self, 'tag'):
self.tag = osp.basename(filename)[:-3]
if not hasattr(self, 'depends'):
self.depends = []
elif isinstance(self.depends, str):
self.depends = [self.depends]
if not hasattr(self, 'upgrader'):
print "Error: no upgrader method for", self.tag
sys.exit(1)
elif not isinstance(self.upgrader, types.FunctionType):
print "Error: 'upgrader' for %s is %s, not function", \
self.tag, type(self)
sys.exit(1)
if hasattr(self, 'legacy_version'):
Upgrader.legacy[self.legacy_version] = self
Upgrader.by_tag[self.tag] = self
Upgrader.tag_set.add(self.tag)
def ready(self, tags):
for dep in self.depends:
if dep not in tags:
return False
return True
def upgrade(self, cpt):
(self.upgrader)(cpt)
verboseprint("applied upgrade for", self.tag)
@staticmethod
def get(tag):
return Upgrader.by_tag[tag]
@staticmethod
def load_all():
util_dir = osp.dirname(osp.abspath(__file__))
for py in glob.glob(util_dir + '/cpt_upgraders/*.py'):
Upgrader(py)
# make linear dependences for legacy versions
i = 3
while i in Upgrader.legacy:
Upgrader.legacy[i].depends = [Upgrader.legacy[i-1].tag]
i = i + 1
def process_file(path, **kwargs):
if not osp.isfile(path):
import errno
raise IOError(ennro.ENOENT, "No such file", path)
verboseprint("Processing file %s...." % path)
if kwargs.get('backup', True):
import shutil
shutil.copyfile(path, path + '.bak')
cpt = ConfigParser.SafeConfigParser()
# gem5 is case sensitive with paramaters
cpt.optionxform = str
# Read the current data
cpt_file = file(path, 'r')
cpt.readfp(cpt_file)
cpt_file.close()
change = False
# Make sure we know what we're starting from
if cpt.has_option('root','cpt_ver'):
cpt_ver = cpt.getint('root','cpt_ver')
# Legacy linear checkpoint version
# convert to list of tags before proceeding
tags = set([])
for i in xrange(2, cpt_ver+1):
tags.add(Upgrader.legacy[i].tag)
verboseprint("performed legacy version -> tags conversion")
change = True
cpt.remove_option('root', 'cpt_ver')
elif cpt.has_option('Globals','version_tags'):
tags = set((''.join(cpt.get('Globals','version_tags'))).split())
else:
print "fatal: no version information in checkpoint"
exit(1)
verboseprint("has tags", ' '.join(tags))
# If the current checkpoint has a tag we don't know about, we have
# a divergence that (in general) must be addressed by (e.g.) merging
# simulator support for its changes.
unknown_tags = tags - Upgrader.tag_set
if unknown_tags:
print "warning: upgrade script does not recognize the following "\
"tags in this checkpoint:", ' '.join(unknown_tags)
# Apply migrations for tags not in checkpoint, respecting dependences
to_apply = Upgrader.tag_set - tags
while to_apply:
ready = set([ t for t in to_apply if Upgrader.get(t).ready(tags) ])
if not ready:
print "could not apply these upgrades:", ' '.join(to_apply)
print "upgrade dependences impossible to resolve; aborting"
exit(1)
for tag in ready:
Upgrader.get(tag).upgrade(cpt)
tags.add(tag)
change = True
to_apply -= ready
if not change:
verboseprint("...nothing to do")
return
cpt.set('Globals', 'version_tags', ' '.join(tags))
# Write the old data back
verboseprint("...completed")
cpt.write(file(path, 'w'))
if __name__ == '__main__':
from optparse import OptionParser, SUPPRESS_HELP
parser = OptionParser("usage: %prog [options] <filename or directory>")
parser.add_option("-r", "--recurse", action="store_true",
help="Recurse through all subdirectories modifying "\
"each checkpoint that is found")
parser.add_option("-N", "--no-backup", action="store_false",
dest="backup", default=True,
help="Do no backup each checkpoint before modifying it")
parser.add_option("-v", "--verbose", action="store_true",
help="Print out debugging information as")
parser.add_option("--get-cc-file", action="store_true",
# used during build; generate src/sim/tags.cc and exit
help=SUPPRESS_HELP)
(options, args) = parser.parse_args()
verbose_print = options.verbose
Upgrader.load_all()
if options.get_cc_file:
print "// this file is auto-generated by util/cpt_upgrader.py"
print "#include <string>"
print "#include <set>"
print
print "std::set<std::string> version_tags = {"
for tag in Upgrader.tag_set:
print " \"%s\"," % tag
print "};"
exit(0)
elif len(args) != 1:
parser.error("You must specify a checkpoint file to modify or a "\
"directory of checkpoints to recursively update")
# Deal with shell variables and ~
path = osp.expandvars(osp.expanduser(args[0]))
# Process a single file if we have it
if osp.isfile(path):
process_file(path, **vars(options))
# Process an entire directory
elif osp.isdir(path):
cpt_file = osp.join(path, 'm5.cpt')
if options.recurse:
# Visit very file and see if it matches
for root,dirs,files in os.walk(path):
for name in files:
if name == 'm5.cpt':
process_file(osp.join(root,name), **vars(options))
for dir in dirs:
pass
# Maybe someone passed a cpt.XXXXXXX directory and not m5.cpt
elif osp.isfile(cpt_file):
process_file(cpt_file, **vars(options))
else:
print "Error: checkpoint file not found at in %s " % path,
print "and recurse not specified"
sys.exit(1)
sys.exit(0)