switcheroo.py revision 11988
1# Copyright (c) 2012 ARM Limited
2# All rights reserved.
3#
4# The license below extends only to copyright in the software and shall
5# not be construed as granting a license to any other intellectual
6# property including but not limited to intellectual property relating
7# to a hardware implementation of the functionality of the software
8# licensed hereunder.  You may use the software subject to the license
9# terms below provided that you ensure that this notice is replicated
10# unmodified and in its entirety in all distributions of the software,
11# modified or unmodified, in source code or in binary form.
12#
13# Redistribution and use in source and binary forms, with or without
14# modification, are permitted provided that the following conditions are
15# met: redistributions of source code must retain the above copyright
16# notice, this list of conditions and the following disclaimer;
17# redistributions in binary form must reproduce the above copyright
18# notice, this list of conditions and the following disclaimer in the
19# documentation and/or other materials provided with the distribution;
20# neither the name of the copyright holders nor the names of its
21# contributors may be used to endorse or promote products derived from
22# this software without specific prior written permission.
23#
24# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
25# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
26# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
27# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
28# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
29# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
30# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
34# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35#
36# Authors: Andreas Sandberg
37
38import m5
39import _m5
40from m5.objects import *
41m5.util.addToPath('../configs/')
42from common.Caches import *
43
44class Sequential:
45    """Sequential CPU switcher.
46
47    The sequential CPU switches between all CPUs in a system in
48    order. The CPUs in the system must have been prepared for
49    switching, which in practice means that only one CPU is switched
50    in. base_config.BaseFSSwitcheroo can be used to create such a
51    system.
52    """
53    def __init__(self, cpus):
54        self.first_cpu = None
55        for (cpuno, cpu) in enumerate(cpus):
56            if not cpu.switched_out:
57                if self.first_cpu != None:
58                    fatal("More than one CPU is switched in");
59                self.first_cpu = cpuno
60
61        if self.first_cpu == None:
62            fatal("The system contains no switched in CPUs")
63
64        self.cur_cpu = self.first_cpu
65        self.cpus = cpus
66
67    def next(self):
68        self.cur_cpu = (self.cur_cpu + 1) % len(self.cpus)
69        return self.cpus[self.cur_cpu]
70
71    def first(self):
72        return self.cpus[self.first_cpu]
73
74def run_test(root, switcher=None, freq=1000, verbose=False):
75    """Test runner for CPU switcheroo tests.
76
77    The switcheroo test runner is used to switch CPUs in a system that
78    has been prepared for CPU switching. Such systems should have
79    multiple CPUs when they are instantiated, but only one should be
80    switched in. Such configurations can be created using the
81    base_config.BaseFSSwitcheroo class.
82
83    A CPU switcher object is used to control switching. The default
84    switcher sequentially switches between all CPUs in a system,
85    starting with the CPU that is currently switched in.
86
87    Unlike most other test runners, this one automatically configures
88    the memory mode of the system based on the first CPU the switcher
89    reports.
90
91    Keyword Arguments:
92      switcher -- CPU switcher implementation. See Sequential for
93                  an example implementation.
94      period -- Switching frequency in Hz.
95      verbose -- Enable output at each switch (suppressed by default).
96    """
97
98    if switcher == None:
99        switcher = Sequential(root.system.cpu)
100
101    current_cpu = switcher.first()
102    system = root.system
103    system.mem_mode = type(current_cpu).memory_mode()
104
105    # Suppress "Entering event queue" messages since we get tons of them.
106    # Worse yet, they include the timestamp, which makes them highly
107    # variable and unsuitable for comparing as test outputs.
108    if not verbose:
109        _m5.core.setLogLevel(_m5.core.LogLevel.WARN)
110
111    # instantiate configuration
112    m5.instantiate()
113
114    # Determine the switching period, this has to be done after
115    # instantiating the system since the time base must be fixed.
116    period = m5.ticks.fromSeconds(1.0 / freq)
117    while True:
118        exit_event = m5.simulate(period)
119        exit_cause = exit_event.getCause()
120
121        if exit_cause == "simulate() limit reached":
122            next_cpu = switcher.next()
123
124            if verbose:
125                print "Switching CPUs..."
126                print "Next CPU: %s" % type(next_cpu)
127            m5.drain()
128            if current_cpu != next_cpu:
129                m5.switchCpus(system, [ (current_cpu, next_cpu) ],
130                              verbose=verbose)
131            else:
132                print "Source CPU and destination CPU are the same, skipping..."
133            current_cpu = next_cpu
134        elif exit_cause == "target called exit()" or \
135                exit_cause == "m5_exit instruction encountered":
136
137            sys.exit(0)
138        else:
139            print "Test failed: Unknown exit cause: %s" % exit_cause
140            sys.exit(1)
141