shivampotdar / ChampSim-CAWS

ChampSim

Compile

ChampSim takes five parameters: Branch predictor, L1D prefetcher, L2C prefetcher, LLC replacement policy, and the number of cores. For example, ./build_champsim.sh bimodal no no lru 1 builds a single-core processor with bimodal branch predictor, no L1/L2 data prefetchers, and the baseline LRU replacement policy for the LLC.

$ ./build_champsim.sh bimodal no no no no lru 1

$ ./build_champsim.sh ${BRANCH} ${L1I_PREFETCHER} ${L1D_PREFETCHER} ${L2C_PREFETCHER} ${LLC_PREFETCHER} ${LLC_REPLACEMENT} ${NUM_CORE}

Run simulation

Execute run_champsim.sh with proper input arguments. The default TRACE_DIR in run_champsim.sh is set to $PWD/dpc3_traces.

• Single-core simulation: Run simulation with run_champsim.sh script.

Usage: ./run_champsim.sh [BINARY] [N_WARM] [N_SIM] [TRACE] [OPTION]
$ ./run_champsim.sh bimodal-no-no-no-lru-1core 1 10 hello_world.trace.xz

${BINARY}: ChampSim binary compiled by "build_champsim.sh" (bimodal-no-no-lru-1core)
${N_WARM}: number of instructions for warmup (1 million)
${N_SIM}:  number of instructinos for detailed simulation (10 million)
${TRACE}: trace name (400.perlbench-41B.champsimtrace.xz)
${OPTION}: extra option for "-low_bandwidth" (src/main.cc)

Simulation results will be stored under "results_${N_SIM}M" as a form of "${TRACE}-${BINARY}-${OPTION}.txt".

How to create traces

The included Pin Tool champsim_tracer.cpp can be used to generate new traces. We used Pin 3.2 (pin-3.2-81205-gcc-linux), and it may require installing libdwarf.so, libelf.so, or other libraries, if you do not already have them. Please refer to the Pin documentation (https://software.intel.com/sites/landingpage/pintool/docs/81205/Pin/html/) for working with Pin 3.2.

Get this version of Pin:

wget http://software.intel.com/sites/landingpage/pintool/downloads/pin-3.2-81205-gcc-linux.tar.gz

Use the Pin tool like this

pin -t obj-intel64/champsim_tracer.so -- <your program here>

The tracer has three options you can set:

-o
Specify the output file for your trace.
The default is default_trace.champsim

-s <number>
Specify the number of instructions to skip in the program before tracing begins.
The default value is 0.

-t <number>
The number of instructions to trace, after -s instructions have been skipped.
The default value is 1,000,000.

For example, you could trace 200,000 instructions of the program ls, after skipping the first 100,000 instructions, with this command:

pin -t obj/champsim_tracer.so -o traces/ls_trace.champsim -s 100000 -t 200000 -- ls