cluster.py revision 8801:1a84c6a81299
15952Ssaidi@eecs.umich.edu# Copyright (c) 2006-2007 The Regents of The University of Michigan
25952Ssaidi@eecs.umich.edu# All rights reserved.
35952Ssaidi@eecs.umich.edu#
45952Ssaidi@eecs.umich.edu# Redistribution and use in source and binary forms, with or without
55952Ssaidi@eecs.umich.edu# modification, are permitted provided that the following conditions are
65952Ssaidi@eecs.umich.edu# met: redistributions of source code must retain the above copyright
75952Ssaidi@eecs.umich.edu# notice, this list of conditions and the following disclaimer;
85952Ssaidi@eecs.umich.edu# redistributions in binary form must reproduce the above copyright
95952Ssaidi@eecs.umich.edu# notice, this list of conditions and the following disclaimer in the
105952Ssaidi@eecs.umich.edu# documentation and/or other materials provided with the distribution;
115952Ssaidi@eecs.umich.edu# neither the name of the copyright holders nor the names of its
125952Ssaidi@eecs.umich.edu# contributors may be used to endorse or promote products derived from
135952Ssaidi@eecs.umich.edu# this software without specific prior written permission.
145952Ssaidi@eecs.umich.edu#
155952Ssaidi@eecs.umich.edu# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
165952Ssaidi@eecs.umich.edu# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
175952Ssaidi@eecs.umich.edu# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
185952Ssaidi@eecs.umich.edu# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
195952Ssaidi@eecs.umich.edu# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
205952Ssaidi@eecs.umich.edu# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
215952Ssaidi@eecs.umich.edu# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
225952Ssaidi@eecs.umich.edu# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
235952Ssaidi@eecs.umich.edu# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
245952Ssaidi@eecs.umich.edu# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
255952Ssaidi@eecs.umich.edu# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
265952Ssaidi@eecs.umich.edu#
275952Ssaidi@eecs.umich.edu# Authors: Ron Dreslinski
285952Ssaidi@eecs.umich.edu
295952Ssaidi@eecs.umich.edu# Simple test script
305952Ssaidi@eecs.umich.edu#
315952Ssaidi@eecs.umich.edu# "m5 test.py"
325952Ssaidi@eecs.umich.edu
335952Ssaidi@eecs.umich.eduimport os
346216Snate@binkert.orgimport optparse
356216Snate@binkert.orgimport sys
366216Snate@binkert.org
376216Snate@binkert.orgimport m5
386216Snate@binkert.orgfrom m5.objects import *
396216Snate@binkert.org
405952Ssaidi@eecs.umich.edum5.util.addToPath('../common')
416216Snate@binkert.org
426216Snate@binkert.org# --------------------
435952Ssaidi@eecs.umich.edu# Define Command Line Options
445952Ssaidi@eecs.umich.edu# ====================
455952Ssaidi@eecs.umich.edu
465952Ssaidi@eecs.umich.eduparser = optparse.OptionParser()
475952Ssaidi@eecs.umich.edu
485952Ssaidi@eecs.umich.eduparser.add_option("-d", "--detailed", action="store_true")
495952Ssaidi@eecs.umich.eduparser.add_option("-t", "--timing", action="store_true")
505952Ssaidi@eecs.umich.eduparser.add_option("-m", "--maxtick", type="int")
515952Ssaidi@eecs.umich.eduparser.add_option("-c", "--numclusters",
525952Ssaidi@eecs.umich.edu                  help="Number of clusters", type="int")
535952Ssaidi@eecs.umich.eduparser.add_option("-n", "--numcpus",
545952Ssaidi@eecs.umich.edu                  help="Number of cpus in total", type="int")
555952Ssaidi@eecs.umich.eduparser.add_option("-f", "--frequency",
565952Ssaidi@eecs.umich.edu                  default = "1GHz",
576002Snate@binkert.org                  help="Frequency of each CPU")
585952Ssaidi@eecs.umich.eduparser.add_option("--l1size",
595952Ssaidi@eecs.umich.edu                  default = "32kB")
605952Ssaidi@eecs.umich.eduparser.add_option("--l1latency",
615952Ssaidi@eecs.umich.edu                  default = 1)
625952Ssaidi@eecs.umich.eduparser.add_option("--l2size",
635952Ssaidi@eecs.umich.edu                  default = "256kB")
645952Ssaidi@eecs.umich.eduparser.add_option("--l2latency",
655952Ssaidi@eecs.umich.edu                  default = 10)
665952Ssaidi@eecs.umich.eduparser.add_option("--rootdir",
675952Ssaidi@eecs.umich.edu                  help="ROot directory of Splash2",
685952Ssaidi@eecs.umich.edu                  default="/dist/splash2/codes/")
695952Ssaidi@eecs.umich.eduparser.add_option("-b", "--benchmark",
705952Ssaidi@eecs.umich.edu                  help="Splash 2 benchmark to run")
715952Ssaidi@eecs.umich.edu
725952Ssaidi@eecs.umich.edu(options, args) = parser.parse_args()
735952Ssaidi@eecs.umich.edu
745952Ssaidi@eecs.umich.eduif args:
755952Ssaidi@eecs.umich.edu    print "Error: script doesn't take any positional arguments"
765952Ssaidi@eecs.umich.edu    sys.exit(1)
775952Ssaidi@eecs.umich.edu
785952Ssaidi@eecs.umich.edu# --------------------
795952Ssaidi@eecs.umich.edu# Define Splash2 Benchmarks
805952Ssaidi@eecs.umich.edu# ====================
815952Ssaidi@eecs.umich.educlass Cholesky(LiveProcess):
825952Ssaidi@eecs.umich.edu        executable = options.rootdir + '/kernels/cholesky/CHOLESKY'
835952Ssaidi@eecs.umich.edu        cmd = 'CHOLESKY -p' + str(options.numcpus) + ' '\
845952Ssaidi@eecs.umich.edu             + options.rootdir + '/kernels/cholesky/inputs/tk23.O'
855952Ssaidi@eecs.umich.edu
865952Ssaidi@eecs.umich.educlass FFT(LiveProcess):
875952Ssaidi@eecs.umich.edu        executable = options.rootdir + 'kernels/fft/FFT'
885952Ssaidi@eecs.umich.edu        cmd = 'FFT -p' + str(options.numcpus) + ' -m18'
895952Ssaidi@eecs.umich.edu
905952Ssaidi@eecs.umich.educlass LU_contig(LiveProcess):
915952Ssaidi@eecs.umich.edu        executable = options.rootdir + 'kernels/lu/contiguous_blocks/LU'
925952Ssaidi@eecs.umich.edu        cmd = 'LU -p' + str(options.numcpus)
935952Ssaidi@eecs.umich.edu
945952Ssaidi@eecs.umich.educlass LU_noncontig(LiveProcess):
955952Ssaidi@eecs.umich.edu        executable = options.rootdir + 'kernels/lu/non_contiguous_blocks/LU'
965952Ssaidi@eecs.umich.edu        cmd = 'LU -p' + str(options.numcpus)
975952Ssaidi@eecs.umich.edu
985952Ssaidi@eecs.umich.educlass Radix(LiveProcess):
995952Ssaidi@eecs.umich.edu        executable = options.rootdir + 'kernels/radix/RADIX'
1005952Ssaidi@eecs.umich.edu        cmd = 'RADIX -n524288 -p' + str(options.numcpus)
1015952Ssaidi@eecs.umich.edu
1025952Ssaidi@eecs.umich.educlass Barnes(LiveProcess):
1035952Ssaidi@eecs.umich.edu        executable = options.rootdir + 'apps/barnes/BARNES'
1045952Ssaidi@eecs.umich.edu        cmd = 'BARNES'
1055952Ssaidi@eecs.umich.edu        input = options.rootdir + 'apps/barnes/input.p' + str(options.numcpus)
1065952Ssaidi@eecs.umich.edu
1075952Ssaidi@eecs.umich.educlass FMM(LiveProcess):
1085952Ssaidi@eecs.umich.edu        executable = options.rootdir + 'apps/fmm/FMM'
1095952Ssaidi@eecs.umich.edu        cmd = 'FMM'
1105952Ssaidi@eecs.umich.edu        input = options.rootdir + 'apps/fmm/inputs/input.2048.p' + str(options.numcpus)
1115952Ssaidi@eecs.umich.edu
1125952Ssaidi@eecs.umich.educlass Ocean_contig(LiveProcess):
1135952Ssaidi@eecs.umich.edu        executable = options.rootdir + 'apps/ocean/contiguous_partitions/OCEAN'
1145952Ssaidi@eecs.umich.edu        cmd = 'OCEAN -p' + str(options.numcpus)
1155952Ssaidi@eecs.umich.edu
1165952Ssaidi@eecs.umich.educlass Ocean_noncontig(LiveProcess):
1175952Ssaidi@eecs.umich.edu        executable = options.rootdir + 'apps/ocean/non_contiguous_partitions/OCEAN'
1185952Ssaidi@eecs.umich.edu        cmd = 'OCEAN -p' + str(options.numcpus)
1195952Ssaidi@eecs.umich.edu
1205952Ssaidi@eecs.umich.educlass Raytrace(LiveProcess):
1215952Ssaidi@eecs.umich.edu        executable = options.rootdir + 'apps/raytrace/RAYTRACE'
1225952Ssaidi@eecs.umich.edu        cmd = 'RAYTRACE -p' + str(options.numcpus) + ' ' \
1235952Ssaidi@eecs.umich.edu             + options.rootdir + 'apps/raytrace/inputs/teapot.env'
1245952Ssaidi@eecs.umich.edu
1255952Ssaidi@eecs.umich.educlass Water_nsquared(LiveProcess):
1265952Ssaidi@eecs.umich.edu        executable = options.rootdir + 'apps/water-nsquared/WATER-NSQUARED'
1275952Ssaidi@eecs.umich.edu        cmd = 'WATER-NSQUARED'
1285952Ssaidi@eecs.umich.edu        input = options.rootdir + 'apps/water-nsquared/input.p' + str(options.numcpus)
1295952Ssaidi@eecs.umich.edu
1305952Ssaidi@eecs.umich.educlass Water_spatial(LiveProcess):
1315952Ssaidi@eecs.umich.edu        executable = options.rootdir + 'apps/water-spatial/WATER-SPATIAL'
1325952Ssaidi@eecs.umich.edu        cmd = 'WATER-SPATIAL'
1335952Ssaidi@eecs.umich.edu        input = options.rootdir + 'apps/water-spatial/input.p' + str(options.numcpus)
1345952Ssaidi@eecs.umich.edu
1355952Ssaidi@eecs.umich.edu
1365952Ssaidi@eecs.umich.edu# --------------------
1375952Ssaidi@eecs.umich.edu# Base L1 Cache Definition
1385952Ssaidi@eecs.umich.edu# ====================
1395952Ssaidi@eecs.umich.edu
1405952Ssaidi@eecs.umich.educlass L1(BaseCache):
1415952Ssaidi@eecs.umich.edu    latency = options.l1latency
1425952Ssaidi@eecs.umich.edu    block_size = 64
1435952Ssaidi@eecs.umich.edu    mshrs = 12
1445952Ssaidi@eecs.umich.edu    tgts_per_mshr = 8
1455952Ssaidi@eecs.umich.edu
1465952Ssaidi@eecs.umich.edu# ----------------------
1475952Ssaidi@eecs.umich.edu# Base L2 Cache Definition
1485952Ssaidi@eecs.umich.edu# ----------------------
1495952Ssaidi@eecs.umich.edu
1505952Ssaidi@eecs.umich.educlass L2(BaseCache):
1515952Ssaidi@eecs.umich.edu    block_size = 64
1525952Ssaidi@eecs.umich.edu    latency = options.l2latency
1535952Ssaidi@eecs.umich.edu    mshrs = 92
1545952Ssaidi@eecs.umich.edu    tgts_per_mshr = 16
1555952Ssaidi@eecs.umich.edu    write_buffers = 8
1565952Ssaidi@eecs.umich.edu
1575952Ssaidi@eecs.umich.edu# ----------------------
1585952Ssaidi@eecs.umich.edu# Define the clusters with their cpus
1595952Ssaidi@eecs.umich.edu# ----------------------
1605952Ssaidi@eecs.umich.educlass Cluster:
1615952Ssaidi@eecs.umich.edu    pass
1625952Ssaidi@eecs.umich.edu
1635952Ssaidi@eecs.umich.educpusPerCluster = options.numcpus/options.numclusters
1645952Ssaidi@eecs.umich.edu
1655952Ssaidi@eecs.umich.edubusFrequency = Frequency(options.frequency)
1665952Ssaidi@eecs.umich.edubusFrequency *= cpusPerCluster
1675952Ssaidi@eecs.umich.edu
1685952Ssaidi@eecs.umich.eduall_cpus = []
1695952Ssaidi@eecs.umich.eduall_l1s = []
1705952Ssaidi@eecs.umich.eduall_l1buses = []
1715952Ssaidi@eecs.umich.eduif options.timing:
1725952Ssaidi@eecs.umich.edu    clusters = [ Cluster() for i in xrange(options.numclusters)]
1735952Ssaidi@eecs.umich.edu    for j in xrange(options.numclusters):
1745952Ssaidi@eecs.umich.edu        clusters[j].id = j
1755952Ssaidi@eecs.umich.edu    for cluster in clusters:
1765952Ssaidi@eecs.umich.edu        cluster.clusterbus = Bus(clock=busFrequency)
1775952Ssaidi@eecs.umich.edu        all_l1buses += [cluster.clusterbus]
1785952Ssaidi@eecs.umich.edu        cluster.cpus = [TimingSimpleCPU(cpu_id = i + cluster.id,
1795952Ssaidi@eecs.umich.edu                                        clock=options.frequency)
1805952Ssaidi@eecs.umich.edu                        for i in xrange(cpusPerCluster)]
1815952Ssaidi@eecs.umich.edu        all_cpus += cluster.cpus
1825952Ssaidi@eecs.umich.edu        cluster.l1 = L1(size=options.l1size, assoc = 4)
1835952Ssaidi@eecs.umich.edu        all_l1s += [cluster.l1]
1845952Ssaidi@eecs.umich.eduelif options.detailed:
1855952Ssaidi@eecs.umich.edu    clusters = [ Cluster() for i in xrange(options.numclusters)]
1865952Ssaidi@eecs.umich.edu    for j in xrange(options.numclusters):
1875952Ssaidi@eecs.umich.edu        clusters[j].id = j
1885952Ssaidi@eecs.umich.edu    for cluster in clusters:
1895952Ssaidi@eecs.umich.edu        cluster.clusterbus = Bus(clock=busFrequency)
1905952Ssaidi@eecs.umich.edu        all_l1buses += [cluster.clusterbus]
1915952Ssaidi@eecs.umich.edu        cluster.cpus = [DerivO3CPU(cpu_id = i + cluster.id,
1925952Ssaidi@eecs.umich.edu                                   clock=options.frequency)
1935952Ssaidi@eecs.umich.edu                        for i in xrange(cpusPerCluster)]
1945952Ssaidi@eecs.umich.edu        all_cpus += cluster.cpus
1955952Ssaidi@eecs.umich.edu        cluster.l1 = L1(size=options.l1size, assoc = 4)
1965952Ssaidi@eecs.umich.edu        all_l1s += [cluster.l1]
1975952Ssaidi@eecs.umich.eduelse:
1985952Ssaidi@eecs.umich.edu    clusters = [ Cluster() for i in xrange(options.numclusters)]
1995952Ssaidi@eecs.umich.edu    for j in xrange(options.numclusters):
2005952Ssaidi@eecs.umich.edu        clusters[j].id = j
2015952Ssaidi@eecs.umich.edu    for cluster in clusters:
2025952Ssaidi@eecs.umich.edu        cluster.clusterbus = Bus(clock=busFrequency)
2035952Ssaidi@eecs.umich.edu        all_l1buses += [cluster.clusterbus]
2045952Ssaidi@eecs.umich.edu        cluster.cpus = [AtomicSimpleCPU(cpu_id = i + cluster.id,
2055952Ssaidi@eecs.umich.edu                                        clock=options.frequency)
2065952Ssaidi@eecs.umich.edu                        for i in xrange(cpusPerCluster)]
2075952Ssaidi@eecs.umich.edu        all_cpus += cluster.cpus
2085952Ssaidi@eecs.umich.edu        cluster.l1 = L1(size=options.l1size, assoc = 4)
2095952Ssaidi@eecs.umich.edu        all_l1s += [cluster.l1]
2105952Ssaidi@eecs.umich.edu
2115952Ssaidi@eecs.umich.edu# ----------------------
2125952Ssaidi@eecs.umich.edu# Create a system, and add system wide objects
2135952Ssaidi@eecs.umich.edu# ----------------------
2145952Ssaidi@eecs.umich.edusystem = System(cpu = all_cpus, l1_ = all_l1s, l1bus_ = all_l1buses, physmem = PhysicalMemory(),
2155952Ssaidi@eecs.umich.edu                membus = Bus(clock = busFrequency))
2165952Ssaidi@eecs.umich.edu
2175952Ssaidi@eecs.umich.edusystem.toL2bus = Bus(clock = busFrequency)
2185952Ssaidi@eecs.umich.edusystem.l2 = L2(size = options.l2size, assoc = 8)
2195952Ssaidi@eecs.umich.edu
2205952Ssaidi@eecs.umich.edu# ----------------------
2215952Ssaidi@eecs.umich.edu# Connect the L2 cache and memory together
2225952Ssaidi@eecs.umich.edu# ----------------------
2235952Ssaidi@eecs.umich.edu
2245952Ssaidi@eecs.umich.edusystem.physmem.port = system.membus.port
2255952Ssaidi@eecs.umich.edusystem.l2.cpu_side = system.toL2bus.port
2265952Ssaidi@eecs.umich.edusystem.l2.mem_side = system.membus.port
2275952Ssaidi@eecs.umich.edu
2285952Ssaidi@eecs.umich.edu# ----------------------
2295952Ssaidi@eecs.umich.edu# Connect the L2 cache and clusters together
2305952Ssaidi@eecs.umich.edu# ----------------------
2315952Ssaidi@eecs.umich.edufor cluster in clusters:
2325952Ssaidi@eecs.umich.edu    cluster.l1.cpu_side = cluster.clusterbus.port
2335952Ssaidi@eecs.umich.edu    cluster.l1.mem_side = system.toL2bus.port
2345952Ssaidi@eecs.umich.edu    for cpu in cluster.cpus:
2355952Ssaidi@eecs.umich.edu        cpu.icache_port = cluster.clusterbus.port
2365952Ssaidi@eecs.umich.edu        cpu.dcache_port = cluster.clusterbus.port
2375952Ssaidi@eecs.umich.edu
2385952Ssaidi@eecs.umich.edu# ----------------------
2395952Ssaidi@eecs.umich.edu# Define the root
2405952Ssaidi@eecs.umich.edu# ----------------------
2415952Ssaidi@eecs.umich.edu
2425952Ssaidi@eecs.umich.eduroot = Root(full_system = False, system = system)
2435952Ssaidi@eecs.umich.edu
2445952Ssaidi@eecs.umich.edu# --------------------
2455952Ssaidi@eecs.umich.edu# Pick the correct Splash2 Benchmarks
2465952Ssaidi@eecs.umich.edu# ====================
2475952Ssaidi@eecs.umich.eduif options.benchmark == 'Cholesky':
2485952Ssaidi@eecs.umich.edu    root.workload = Cholesky()
2495952Ssaidi@eecs.umich.eduelif options.benchmark == 'FFT':
2505952Ssaidi@eecs.umich.edu    root.workload = FFT()
2515952Ssaidi@eecs.umich.eduelif options.benchmark == 'LUContig':
2525952Ssaidi@eecs.umich.edu    root.workload = LU_contig()
2535952Ssaidi@eecs.umich.eduelif options.benchmark == 'LUNoncontig':
2545952Ssaidi@eecs.umich.edu    root.workload = LU_noncontig()
2555952Ssaidi@eecs.umich.eduelif options.benchmark == 'Radix':
2565952Ssaidi@eecs.umich.edu    root.workload = Radix()
2575952Ssaidi@eecs.umich.eduelif options.benchmark == 'Barnes':
2585952Ssaidi@eecs.umich.edu    root.workload = Barnes()
2595952Ssaidi@eecs.umich.eduelif options.benchmark == 'FMM':
2605952Ssaidi@eecs.umich.edu    root.workload = FMM()
2615952Ssaidi@eecs.umich.eduelif options.benchmark == 'OceanContig':
2625952Ssaidi@eecs.umich.edu    root.workload = Ocean_contig()
2635952Ssaidi@eecs.umich.eduelif options.benchmark == 'OceanNoncontig':
2645952Ssaidi@eecs.umich.edu    root.workload = Ocean_noncontig()
2655952Ssaidi@eecs.umich.eduelif options.benchmark == 'Raytrace':
2665952Ssaidi@eecs.umich.edu    root.workload = Raytrace()
2675952Ssaidi@eecs.umich.eduelif options.benchmark == 'WaterNSquared':
2685952Ssaidi@eecs.umich.edu    root.workload = Water_nsquared()
2695952Ssaidi@eecs.umich.eduelif options.benchmark == 'WaterSpatial':
2705952Ssaidi@eecs.umich.edu    root.workload = Water_spatial()
2715952Ssaidi@eecs.umich.eduelse:
2725952Ssaidi@eecs.umich.edu    m5.util.panic("""
2735952Ssaidi@eecs.umich.eduThe --benchmark environment variable was set to something improper.
2745952Ssaidi@eecs.umich.eduUse Cholesky, FFT, LUContig, LUNoncontig, Radix, Barnes, FMM, OceanContig,
2755952Ssaidi@eecs.umich.eduOceanNoncontig, Raytrace, WaterNSquared, or WaterSpatial
2765952Ssaidi@eecs.umich.edu""")
2775952Ssaidi@eecs.umich.edu
2785952Ssaidi@eecs.umich.edu# --------------------
2795952Ssaidi@eecs.umich.edu# Assign the workload to the cpus
2805952Ssaidi@eecs.umich.edu# ====================
2815952Ssaidi@eecs.umich.edu
2825952Ssaidi@eecs.umich.edufor cluster in clusters:
2835952Ssaidi@eecs.umich.edu    for cpu in cluster.cpus:
2845952Ssaidi@eecs.umich.edu        cpu.workload = root.workload
2855952Ssaidi@eecs.umich.edu
2865952Ssaidi@eecs.umich.edu# ----------------------
2875952Ssaidi@eecs.umich.edu# Run the simulation
2885952Ssaidi@eecs.umich.edu# ----------------------
2895952Ssaidi@eecs.umich.edu
2905952Ssaidi@eecs.umich.eduif options.timing or options.detailed:
2915952Ssaidi@eecs.umich.edu    root.system.mem_mode = 'timing'
2925952Ssaidi@eecs.umich.edu
2935952Ssaidi@eecs.umich.edu# instantiate configuration
2945952Ssaidi@eecs.umich.edum5.instantiate()
2955952Ssaidi@eecs.umich.edu
2965952Ssaidi@eecs.umich.edu# simulate until program terminates
2975952Ssaidi@eecs.umich.eduif options.maxtick:
2985952Ssaidi@eecs.umich.edu    exit_event = m5.simulate(options.maxtick)
2995952Ssaidi@eecs.umich.eduelse:
3005952Ssaidi@eecs.umich.edu    exit_event = m5.simulate(m5.MaxTick)
3015952Ssaidi@eecs.umich.edu
3025952Ssaidi@eecs.umich.eduprint 'Exiting @ tick', m5.curTick(), 'because', exit_event.getCause()
3035952Ssaidi@eecs.umich.edu
3045952Ssaidi@eecs.umich.edu