gem5/configs/example/memtest.py
Andreas Hansson f00cba34eb Mem: Make SimpleMemory single ported
This patch changes the simple memory to have a single slave port
rather than a vector port. The simple memory makes no attempts at
modelling the contention between multiple ports, and any such
multiplexing and demultiplexing could be done in a bus (or crossbar)
outside the memory controller. This scenario also matches with the
ongoing work on a SimpleDRAM model, which will be a single-ported
single-channel controller that can be used in conjunction with a bus
(or crossbar) to create a multi-port multi-channel controller.

There are only very few regressions that make use of the vector port,
and these are all for functional accesses only. To facilitate these
cases, memtest and memtest-ruby have been updated to also have a
"functional" bus to perform the (de)multiplexing of the functional
memory accesses.
2012-07-12 12:56:13 -04:00

203 lines
7.5 KiB
Python

# Copyright (c) 2006-2007 The Regents of The University of Michigan
# 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.
#
# Authors: Ron Dreslinski
import optparse
import sys
import m5
from m5.objects import *
parser = optparse.OptionParser()
parser.add_option("-a", "--atomic", action="store_true",
help="Use atomic (non-timing) mode")
parser.add_option("-b", "--blocking", action="store_true",
help="Use blocking caches")
parser.add_option("-l", "--maxloads", metavar="N", default=0,
help="Stop after N loads")
parser.add_option("-m", "--maxtick", type="int", default=m5.MaxTick,
metavar="T",
help="Stop after T ticks")
#
# The "tree" specification is a colon-separated list of one or more
# integers. The first integer is the number of caches/testers
# connected directly to main memory. The last integer in the list is
# the number of testers associated with the uppermost level of memory
# (L1 cache, if there are caches, or main memory if no caches). Thus
# if there is only one integer, there are no caches, and the integer
# specifies the number of testers connected directly to main memory.
# The other integers (if any) specify the number of caches at each
# level of the hierarchy between.
#
# Examples:
#
# "2:1" Two caches connected to memory with a single tester behind each
# (single-level hierarchy, two testers total)
#
# "2:2:1" Two-level hierarchy, 2 L1s behind each of 2 L2s, 4 testers total
#
parser.add_option("-t", "--treespec", type="string", default="8:1",
help="Colon-separated multilevel tree specification, "
"see script comments for details "
"[default: %default]")
parser.add_option("--force-bus", action="store_true",
help="Use bus between levels even with single cache")
parser.add_option("-f", "--functional", type="int", default=0,
metavar="PCT",
help="Target percentage of functional accesses "
"[default: %default]")
parser.add_option("-u", "--uncacheable", type="int", default=0,
metavar="PCT",
help="Target percentage of uncacheable accesses "
"[default: %default]")
parser.add_option("--progress", type="int", default=1000,
metavar="NLOADS",
help="Progress message interval "
"[default: %default]")
(options, args) = parser.parse_args()
if args:
print "Error: script doesn't take any positional arguments"
sys.exit(1)
block_size = 64
try:
treespec = [int(x) for x in options.treespec.split(':')]
numtesters = reduce(lambda x,y: x*y, treespec)
except:
print "Error parsing treespec option"
sys.exit(1)
if numtesters > block_size:
print "Error: Number of testers limited to %s because of false sharing" \
% (block_size)
sys.exit(1)
if len(treespec) < 1:
print "Error parsing treespec"
sys.exit(1)
# define prototype L1 cache
proto_l1 = BaseCache(size = '32kB', assoc = 4, block_size = block_size,
latency = '1ns', tgts_per_mshr = 8)
if options.blocking:
proto_l1.mshrs = 1
else:
proto_l1.mshrs = 4
# build a list of prototypes, one for each level of treespec, starting
# at the end (last entry is tester objects)
prototypes = [ MemTest(atomic=options.atomic, max_loads=options.maxloads,
percent_functional=options.functional,
percent_uncacheable=options.uncacheable,
progress_interval=options.progress) ]
# next comes L1 cache, if any
if len(treespec) > 1:
prototypes.insert(0, proto_l1)
# now add additional cache levels (if any) by scaling L1 params
for scale in treespec[:-2]:
# clone previous level and update params
prev = prototypes[0]
next = prev()
next.size = prev.size * scale
next.latency = prev.latency * 10
next.assoc = prev.assoc * scale
next.mshrs = prev.mshrs * scale
prototypes.insert(0, next)
# system simulated
system = System(funcmem = SimpleMemory(in_addr_map = False),
funcbus = NoncoherentBus(),
physmem = SimpleMemory(latency = "100ns"))
def make_level(spec, prototypes, attach_obj, attach_port):
fanout = spec[0]
parent = attach_obj # use attach obj as config parent too
if len(spec) > 1 and (fanout > 1 or options.force_bus):
port = getattr(attach_obj, attach_port)
new_bus = CoherentBus(clock="500MHz", width=16)
if (port.role == 'MASTER'):
new_bus.slave = port
attach_port = "master"
else:
new_bus.master = port
attach_port = "slave"
parent.cpu_side_bus = new_bus
attach_obj = new_bus
objs = [prototypes[0]() for i in xrange(fanout)]
if len(spec) > 1:
# we just built caches, more levels to go
parent.cache = objs
for cache in objs:
cache.mem_side = getattr(attach_obj, attach_port)
make_level(spec[1:], prototypes[1:], cache, "cpu_side")
else:
# we just built the MemTest objects
parent.cpu = objs
for t in objs:
t.test = getattr(attach_obj, attach_port)
t.functional = system.funcbus.slave
make_level(treespec, prototypes, system.physmem, "port")
# connect reference memory to funcbus
system.funcbus.master = system.funcmem.port
# -----------------------
# run simulation
# -----------------------
root = Root( full_system = False, system = system )
if options.atomic:
root.system.mem_mode = 'atomic'
else:
root.system.mem_mode = 'timing'
# The system port is never used in the tester so merely connect it
# to avoid problems
root.system.system_port = root.system.physmem.port
# Not much point in this being higher than the L1 latency
m5.ticks.setGlobalFrequency('1ns')
# instantiate configuration
m5.instantiate()
# simulate until program terminates
exit_event = m5.simulate(options.maxtick)
print 'Exiting @ tick', m5.curTick(), 'because', exit_event.getCause()