gem5/tests/configs/switcheroo.py
Andreas Sandberg f16c0a4a90 sim: Decouple draining from the SimObject hierarchy
Draining is currently done by traversing the SimObject graph and
calling drain()/drainResume() on the SimObjects. This is not ideal
when non-SimObjects (e.g., ports) need draining since this means that
SimObjects owning those objects need to be aware of this.

This changeset moves the responsibility for finding objects that need
draining from SimObjects and the Python-side of the simulator to the
DrainManager. The DrainManager now maintains a set of all objects that
need draining. To reduce the overhead in classes owning non-SimObjects
that need draining, objects inheriting from Drainable now
automatically register with the DrainManager. If such an object is
destroyed, it is automatically unregistered. This means that drain()
and drainResume() should never be called directly on a Drainable
object.

While implementing the new functionality, the DrainManager has now
been made thread safe. In practice, this means that it takes a lock
whenever it manipulates the set of Drainable objects since SimObjects
in different threads may create Drainable objects
dynamically. Similarly, the drain counter is now an atomic_uint, which
ensures that it is manipulated correctly when objects signal that they
are done draining.

A nice side effect of these changes is that it makes the drain state
changes stricter, which the simulation scripts can exploit to avoid
redundant drains.
2015-07-07 09:51:05 +01:00

138 lines
5.6 KiB
Python

# Copyright (c) 2012 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: Andreas Sandberg
import m5
from m5.objects import *
m5.util.addToPath('../configs/common')
from Caches import *
class Sequential:
"""Sequential CPU switcher.
The sequential CPU switches between all CPUs in a system in
order. The CPUs in the system must have been prepared for
switching, which in practice means that only one CPU is switched
in. base_config.BaseFSSwitcheroo can be used to create such a
system.
"""
def __init__(self, cpus):
self.first_cpu = None
for (cpuno, cpu) in enumerate(cpus):
if not cpu.switched_out:
if self.first_cpu != None:
fatal("More than one CPU is switched in");
self.first_cpu = cpuno
if self.first_cpu == None:
fatal("The system contains no switched in CPUs")
self.cur_cpu = self.first_cpu
self.cpus = cpus
def next(self):
self.cur_cpu = (self.cur_cpu + 1) % len(self.cpus)
return self.cpus[self.cur_cpu]
def first(self):
return self.cpus[self.first_cpu]
def run_test(root, switcher=None, freq=1000, verbose=False):
"""Test runner for CPU switcheroo tests.
The switcheroo test runner is used to switch CPUs in a system that
has been prepared for CPU switching. Such systems should have
multiple CPUs when they are instantiated, but only one should be
switched in. Such configurations can be created using the
base_config.BaseFSSwitcheroo class.
A CPU switcher object is used to control switching. The default
switcher sequentially switches between all CPUs in a system,
starting with the CPU that is currently switched in.
Unlike most other test runners, this one automatically configures
the memory mode of the system based on the first CPU the switcher
reports.
Keyword Arguments:
switcher -- CPU switcher implementation. See Sequential for
an example implementation.
period -- Switching frequency in Hz.
verbose -- Enable output at each switch (suppressed by default).
"""
if switcher == None:
switcher = Sequential(root.system.cpu)
current_cpu = switcher.first()
system = root.system
system.mem_mode = type(current_cpu).memory_mode()
# Suppress "Entering event queue" messages since we get tons of them.
# Worse yet, they include the timestamp, which makes them highly
# variable and unsuitable for comparing as test outputs.
m5.internal.core.cvar.want_info = verbose
# instantiate configuration
m5.instantiate()
# Determine the switching period, this has to be done after
# instantiating the system since the time base must be fixed.
period = m5.ticks.fromSeconds(1.0 / freq)
while True:
exit_event = m5.simulate(period)
exit_cause = exit_event.getCause()
if exit_cause == "simulate() limit reached":
next_cpu = switcher.next()
if verbose:
print "Switching CPUs..."
print "Next CPU: %s" % type(next_cpu)
m5.drain()
if current_cpu != next_cpu:
m5.switchCpus(system, [ (current_cpu, next_cpu) ],
verbose=verbose)
else:
print "Source CPU and destination CPU are the same, skipping..."
current_cpu = next_cpu
elif exit_cause == "target called exit()" or \
exit_cause == "m5_exit instruction encountered":
sys.exit(0)
else:
print "Test failed: Unknown exit cause: %s" % exit_cause
sys.exit(1)