Thanks Ciro. I will follow your recommendations.
Best regards, Abbas Fairouz ------------------------------------------------- Abbas Fairouz, PhD candidate Dept. of ECE, Texas A&M University College Station, TX 77843, USA ------------------------------------------------- On Wed, Sep 12, 2018 at 2:30 AM, Ciro Santilli <ciro.santi...@gmail.com> wrote: > Hey Abbas, Please always reply to the gem5 mailing list, and CC me > when appropriate, > > I can understand why you would like to have a fixed number. > > I think the stats can vary due to a very wide number of complex > factors. Some of those may be more accurate, others no one knows, > others just bugs. > > This can also be observed by the fact that the stats checks have been > CHANGED by a long time, e.g.: > https://www.mail-archive.com/gem5-dev@gem5.org/msg26855.html changes > happen so often that devs haven't found the time to properly > understand and justify them. > > My recommendation is that you re-run your old experiments on the newer > gem5 version, and compare everything there. > > gem5 is not a cycle accurate system simulator, so absolute values or > small variations are not meaningful in general. > > This also teaches us that results obtained with small margins are > generally not meaningful for publication since the noise is too great. > > What that error margin is, I don't know. > > On Tue, Sep 11, 2018 at 3:51 PM Abbas Fairouz <afair...@tamu.edu> wrote: > > > > Hi Ciro, > > > > Thanks for your reply. > > > > The reason I was asking about the differences between these two versions > of GEM5, because I have published a paper two years ago using the old GEM5 > version. Now, I need two do more experiments on GEM5 using new memory > technologies (such as HBM). I'm getting different results in the new GEM5 > version, for the same benchmarks I used in the old GEM5 version. > > > > Is it because the new GEM5 has more accurate: > > 1) Memory modeling? > > 2) Cache modeling? > > 3) CPU modeling? > > > > > > > > > > Best regards, > > Abbas Fairouz > > > > > > ------------------------------------------------- > > Abbas Fairouz, PhD candidate > > Dept. of ECE, Texas A&M University > > College Station, TX 77843, USA > > ------------------------------------------------- > > > > > > On Wed, Sep 5, 2018 at 4:52 AM, Ciro Santilli <ciro.santi...@gmail.com> > wrote: > >> > >> Thanks for the detailed report, > >> > >> I recommend that if you really care about this difference, then do a > bisection of gem5 and pinpoint which commit introduced it, and then tell us > which one it was, possibly also pinging the author for clarification. > >> > >> If you are not familiar with bisection, here is a detailed example that > you should be able to adapt easily for this use case: https://github.com/ > cirosantilli/linux-kernel-module-cheat/tree/83b36867cf06ffdca3ce04296a8568 > d4f37ea13b#bisection > >> > >> > >> On Tue, Sep 4, 2018 at 8:50 PM Abbas Fairouz <afair...@tamu.edu> wrote: > >>> > >>> Hi guys, > >>> > >>> I have simulated a simple "hello world" example on two different > versions of GEM5. I have got two different "system.cpu.numCycles" results > in both simulations. In both simulations, I have been using the same > configurations (linux image, vm, caches, ...etc). > >>> > >>> I will list the parts of the configuration files and "stats.txt" files > for both simulations. > >>> > >>> They have the same path to ~/gem5/system files. > >>> I ran them on the same configuration: FS mode, O3 CPU, CPU speed is > 2GHz, DDR3_1600, l2 cache. > >>> > >>> > >>> Running script is "test.rcS": > >>> > >>> /sbin/m5 resetstats > >>> > >>> echo "Start" > >>> > >>> echo `ls` > >>> > >>> cd test > >>> > >>> ./a.out > >>> > >>> echo "Bye" > >>> > >>> /sbin/m5 exit > >>> > >>> > >>> > >>> "a.out" is a binary code of "hello.c" file: > >>> > >>> #include <stdio.h> > >>> > >>> int main() > >>> > >>> { > >>> > >>> //printf() displays the string inside quotation > >>> > >>> printf("Hello, World!\n"); > >>> > >>> int x = 100 + 5 * 23 - 16 + 6 * 44 - 289 / 4; > >>> > >>> printf("X = %d\n", x); > >>> > >>> > >>> return 0; > >>> > >>> } > >>> > >>> > >>> > >>> > >>> > >>> ========================================================== > >>> > >>> Old GEM5 (gem5-stable-0e86fac7254c) > >>> > >>> In "configs/common/FSConfig.py": > >>> > >>> # Command line > >>> > >>> self.boot_osflags = 'earlyprintk=ttyS0 console=ttyS0 lpj=7999923 ' > + \ > >>> > >>> 'root=/dev/hda1' > >>> > >>> # abbas > >>> > >>> #self.kernel = binary('x86_64-vmlinux-2.6.22.9') > >>> > >>> self.kernel = binary('x86_64-vmlinux-2.6.22.9.smp') > >>> > >>> #self.kernel = binary('x86_64-vmlinux-2.6.28.4-smp') > >>> > >>> return self > >>> > >>> > >>> > >>> In "configs/common/Benchmarks.py": > >>> > >>> elif buildEnv['TARGET_ISA'] == 'x86': > >>> > >>> # abbas > >>> > >>> #return env.get('LINUX_IMAGE', disk('x86root.img')) > >>> > >>> return env.get('LINUX_IMAGE', disk('x86root-taco.img')) > >>> > >>> > >>> > >>> In "configs/common/Simulation.py": > >>> > >>> elif options.fast_forward: > >>> > >>> CPUClass = TmpClass > >>> > >>> # Abbas > >>> > >>> #TmpClass = AtomicSimpleCPU > >>> > >>> #test_mem_mode = 'atomic' > >>> > >>> TmpClass = TimingSimpleCPU > >>> > >>> test_mem_mode = 'timing' > >>> > >>> > >>> > >>> Running GEM5 command: > >>> > >>> ./build/X86/gem5.opt -d m5out/test ./configs/example/fs.py --caches > --l2cache --l1d_size=128kB --script=myscripts/test.rcS > --mem-type=DDR3_1600_x64 --restore-with-cpu=detailed > >>> > >>> > >>> GEM5 terminal (tail): > >>> > >>> TCP cubic registered > >>> > >>> NET: Registered protocol family 1 > >>> > >>> NET: Registered protocol family 10 > >>> > >>> IPv6 over IPv4 tunneling driver > >>> > >>> NET: Registered protocol family 17 > >>> > >>> EXT2-fs warning: maximal mount count reached, running e2fsck is > recommended > >>> > >>> VFS: Mounted root (ext2 filesystem). > >>> > >>> Freeing unused kernel memory: 248k freed > >>> > >>> mounting filesystems... > >>> > >>> loading script... > >>> > >>> Start > >>> > >>> benches bin boot dev etc home lib lib32 lib64 linuxrc lost+found mnt > normal opt parsec proc real root sbin sys test tmp usr var > >>> > >>> Hello > >>> > >>> X = 391 > >>> > >>> Bye > >>> > >>> > >>> > >>> > >>> In "stats.txt" file: > >>> > >>> system.cpu.apic_clk_domain.clock 8000 > # Clock period in ticks > >>> > >>> system.cpu.numCycles 4273712 > # number of cpu cycles simulated > >>> > >>> system.cpu.numWorkItemsStarted 0 > # number of work items this cpu started > >>> > >>> system.cpu.numWorkItemsCompleted 0 > # number of work items this cpu completed > >>> > >>> system.cpu.committedInsts 1954222 > # Number of instructions committed > >>> > >>> system.cpu.committedOps 3584009 > # Number of ops (including micro ops) committed > >>> > >>> system.cpu.num_int_alu_accesses 3508387 > # Number of integer alu accesses > >>> > >>> system.cpu.num_fp_alu_accesses 21132 > # Number of float alu accesses > >>> > >>> system.cpu.num_func_calls 85033 > # number of times a function call or return occured > >>> > >>> system.cpu.num_conditional_control_insts 254623 > # number of instructions that are conditional controls > >>> > >>> system.cpu.num_int_insts 3508387 > # number of integer instructions > >>> > >>> system.cpu.num_fp_insts 21132 > # number of float instructions > >>> > >>> system.cpu.num_int_register_reads 7285240 > # number of times the integer registers were read > >>> > >>> system.cpu.num_int_register_writes 2775300 > # number of times the integer registers were written > >>> > >>> system.cpu.num_fp_register_reads 35511 > # number of times the floating registers were read > >>> > >>> system.cpu.num_fp_register_writes 16891 > # number of times the floating registers were written > >>> > >>> system.cpu.num_cc_register_reads 1862494 > # number of times the CC registers were read > >>> > >>> system.cpu.num_cc_register_writes 1160708 > # number of times the CC registers were written > >>> > >>> system.cpu.num_mem_refs 885650 > # number of memory refs > >>> > >>> system.cpu.num_load_insts 499134 > # Number of load instructions > >>> > >>> system.cpu.num_store_insts 386516 > # Number of store instructions > >>> > >>> system.cpu.num_idle_cycles 109958.492414 > # Number of idle cycles > >>> > >>> system.cpu.num_busy_cycles 4163753.507586 > # Number of busy cycles > >>> > >>> system.cpu.not_idle_fraction 0.974271 > # Percentage of non-idle cycles > >>> > >>> system.cpu.idle_fraction 0.025729 > # Percentage of idle cycles > >>> > >>> system.cpu.Branches 374315 > # Number of branches fetched > >>> > >>> system.cpu.op_class::No_OpClass 22624 0.63% > 0.63% # Class of executed instruction > >>> > >>> system.cpu.op_class::IntAlu 2647876 73.88% > 74.51% # Class of executed instruction > >>> > >>> system.cpu.op_class::IntMult 6228 0.17% > 74.68% # Class of executed instruction > >>> > >>> system.cpu.op_class::IntDiv 3691 0.10% > 74.78% # Class of executed instruction > >>> > >>> system.cpu.op_class::FloatAdd 18119 0.51% > 75.29% # Class of executed instruction > >>> > >>> system.cpu.op_class::FloatCmp 0 0.00% > 75.29% # Class of executed instruction > >>> > >>> system.cpu.op_class::FloatCvt 0 0.00% > 75.29% # Class of executed instruction > >>> > >>> system.cpu.op_class::FloatMult 0 0.00% > 75.29% # Class of executed instruction > >>> > >>> system.cpu.op_class::FloatDiv 0 0.00% > 75.29% # Class of executed instruction > >>> > >>> system.cpu.op_class::FloatSqrt 0 0.00% > 75.29% # Class of executed instruction > >>> > >>> system.cpu.op_class::SimdAdd 0 0.00% > 75.29% # Class of executed instruction > >>> > >>> system.cpu.op_class::SimdAddAcc 0 0.00% > 75.29% # Class of executed instruction > >>> > >>> system.cpu.op_class::SimdAlu 0 0.00% > 75.29% # Class of executed instruction > >>> > >>> system.cpu.op_class::SimdCmp 0 0.00% > 75.29% # Class of executed instruction > >>> > >>> system.cpu.op_class::SimdCvt 0 0.00% > 75.29% # Class of executed instruction > >>> > >>> system.cpu.op_class::SimdMisc 0 0.00% > 75.29% # Class of executed instruction > >>> > >>> system.cpu.op_class::SimdMult 0 0.00% > 75.29% # Class of executed instruction > >>> > >>> > >>> > >>> > >>> > >>> > >>> New GEM5 > >>> > >>> In "configs/common/FSConfig.py": > >>> > >>> # Command line > >>> > >>> if not cmdline: > >>> > >>> cmdline = 'earlyprintk=ttyS0 console=ttyS0 lpj=7999923 > root=/dev/hda1' > >>> > >>> self.boot_osflags = fillInCmdline(mdesc, cmdline) > >>> > >>> # abbas > >>> > >>> #self.kernel = binary('x86_64-vmlinux-2.6.22.9') > >>> > >>> self.kernel = binary('x86_64-vmlinux-2.6.22.9.smp') > >>> > >>> #self.kernel = binary('x86_64-vmlinux-2.6.28.4-smp') > >>> > >>> return self > >>> > >>> > >>> > >>> In "configs/common/Benchmarks.py": > >>> > >>> elif buildEnv['TARGET_ISA'] == 'x86': > >>> > >>> # abbas > >>> > >>> #return env.get('LINUX_IMAGE', disk('x86root.img')) > >>> > >>> #return env.get('LINUX_IMAGE', disk('linux-x86.img')) > >>> > >>> return env.get('LINUX_IMAGE', disk('x86root-taco.img')) > >>> > >>> > >>> > >>> In "configs/common/Simulation.py": > >>> > >>> elif options.fast_forward: > >>> > >>> CPUClass = TmpClass > >>> > >>> # Abbas > >>> > >>> #TmpClass = AtomicSimpleCPU > >>> > >>> #test_mem_mode = 'atomic' > >>> > >>> TmpClass = TimingSimpleCPU > >>> > >>> test_mem_mode = 'timing' > >>> > >>> > >>> > >>> Running GEM5 command: > >>> > >>> ./build/X86/gem5.opt -d m5out/test ./configs/example/fs.py --caches > --l2cache --l1d_size=128kB --script=myscripts/test.rcS > --mem-type=DDR3_1600_8x8 --restore-with-cpu=DerivO3CPU > >>> > >>> > >>> > >>> > >>> GEM5 terminal (tail): > >>> > >>> TCP cubic registered > >>> > >>> NET: Registered protocol family 1 > >>> > >>> NET: Registered protocol family 10 > >>> > >>> IPv6 over IPv4 tunneling driver > >>> > >>> NET: Registered protocol family 17 > >>> > >>> EXT2-fs warning: maximal mount count reached, running e2fsck is > recommended > >>> > >>> VFS: Mounted root (ext2 filesystem). > >>> > >>> Freeing unused kernel memory: 248k freed > >>> > >>> mounting filesystems... > >>> > >>> loading script... > >>> > >>> Start > >>> > >>> benches bin boot dev etc home lib lib32 lib64 linuxrc lost+found mnt > normal opt parsec proc real root sbin sys test tmp usr var > >>> > >>> Hello > >>> > >>> X = 391 > >>> > >>> Bye > >>> > >>> > >>> > >>> > >>> In "stats.txt" file: > >>> > >>> system.cpu_voltage_domain.voltage 1 > # Voltage in Volts > >>> > >>> system.cpu_clk_domain.clock 500 > # Clock period in ticks > >>> > >>> system.cpu.dtb.walker.pwrStateResidencyTicks::UNDEFINED > 5141035093500 # Cumulative time (in ticks) in > various power states > >>> > >>> system.cpu.dtb.rdAccesses 497427 > # TLB accesses on read requests > >>> > >>> system.cpu.dtb.wrAccesses 384596 > # TLB accesses on write requests > >>> > >>> system.cpu.dtb.rdMisses 434 > # TLB misses on read requests > >>> > >>> system.cpu.dtb.wrMisses 163 > # TLB misses on write requests > >>> > >>> system.cpu.apic_clk_domain.clock 8000 > # Clock period in ticks > >>> > >>> system.cpu.interrupts.pwrStateResidencyTicks::UNDEFINED > 5141035093500 # Cumulative time (in ticks) in > various power states > >>> > >>> system.cpu.itb.walker.pwrStateResidencyTicks::UNDEFINED > 5141035093500 # Cumulative time (in ticks) in > various power states > >>> > >>> system.cpu.itb.rdAccesses 0 > # TLB accesses on read requests > >>> > >>> system.cpu.itb.wrAccesses 2532817 > # TLB accesses on write requests > >>> > >>> system.cpu.itb.rdMisses 0 > # TLB misses on read requests > >>> > >>> system.cpu.itb.wrMisses 640 > # TLB misses on write requests > >>> > >>> system.cpu.numPwrStateTransitions 64 > # Number of power state transitions > >>> > >>> system.cpu.pwrStateClkGateDist::samples 32 > # Distribution of time spent in the clock gated state > >>> > >>> system.cpu.pwrStateClkGateDist::mean 1344463.875000 > # Distribution of time spent in the clock gated state > >>> > >>> system.cpu.pwrStateClkGateDist::stdev 1757712.048093 > # Distribution of time spent in the clock gated state > >>> > >>> system.cpu.pwrStateClkGateDist::1000-5e+10 32 100.00% > 100.00% # Distribution of time spent in the clock gated state > >>> > >>> system.cpu.pwrStateClkGateDist::min_value 219525 > # Distribution of time spent in the clock gated state > >>> > >>> system.cpu.pwrStateClkGateDist::max_value 4847757 > # Distribution of time spent in the clock gated state > >>> > >>> system.cpu.pwrStateClkGateDist::total 32 > # Distribution of time spent in the clock gated state > >>> > >>> system.cpu.pwrStateResidencyTicks::ON 2768793027 > # Cumulative time (in ticks) in various power states > >>> > >>> system.cpu.pwrStateResidencyTicks::CLK_GATED 43022844 > # Cumulative time (in ticks) in various power states > >>> > >>> system.cpu.numCycles 4233161 > # number of cpu cycles simulated > >>> > >>> system.cpu.numWorkItemsStarted 0 > # number of work items this cpu started > >>> > >>> system.cpu.numWorkItemsCompleted 0 > # number of work items this cpu completed > >>> > >>> system.cpu.kern.inst.arm 0 > # number of arm instructions executed > >>> > >>> system.cpu.kern.inst.quiesce 0 > # number of quiesce instructions executed > >>> > >>> system.cpu.committedInsts 1956251 > # Number of instructions committed > >>> > >>> system.cpu.committedOps 3569940 > # Number of ops (including micro ops) committed > >>> > >>> system.cpu.num_int_alu_accesses 3492413 > # Number of integer alu accesses > >>> > >>> system.cpu.num_fp_alu_accesses 21132 > # Number of float alu accesses > >>> > >>> system.cpu.num_vec_alu_accesses 0 > # Number of vector alu accesses > >>> > >>> system.cpu.num_func_calls 84965 > # number of times a function call or return > >>> > >>> > >>> > >>> > >>> ========================================================== > >>> > >>> > >>> > >>> Can anyone explains to me why both simulations does not have the same > number of cycles? > >>> > >>> Old GEM5: system.cpu.numCycles 4273712 > >>> New GEM5: system.cpu.numCycles 4233161 > >>> > >>> > >>> Best regards, > >>> Abbas Fairouz > >>> > >>> > >>> ------------------------------------------------- > >>> Abbas Fairouz, PhD candidate > >>> Dept. of ECE, Texas A&M University > >>> College Station, TX 77843, USA > >>> ------------------------------------------------- > >>> > >>> _______________________________________________ > >>> gem5-users mailing list > >>> gem5-users@gem5.org > >>> http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users > > > > >
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