Add README for benchmark

Author: haochengxia

benchmark/README.md

@@ -0,0 +1,17 @@
+# Benchmark
+
+We can run simulation to compare the performance of native c executable file `cachesim`, and the python binding via [simulation.py](./simulation.py).
+
+## Example
+
+```bash
+# at the root dir of the repository
+bash script/install.sh
+python benchmark/simulation.py  --trace_path=./src/libCacheSim/data/cloudPhysicsIO.oracleGeneral.bin
+```
+
+## Usage
+
+```
+python benchmark/simulation.py  -h
+```