diff --git a/Dockerfile b/Dockerfile
index 367558df..d0b5cc0b 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -36,6 +36,8 @@ RUN pip3 install  \
 
 RUN pip3 install matplotlib
 
+RUN apt install openmpi-bin openmpi-common libopenmpi-dev -y
+
 COPY . .
 
 RUN pip3 install . --timeout 100
diff --git a/README.md b/README.md
index 49ac9e4f..78ad8804 100644
--- a/README.md
+++ b/README.md
@@ -258,7 +258,7 @@ print(c.name())
 # Output: c
 ```
 
-###Operations
+### Operations
 
 
 Jittor'op is simular with numpy. Let's try some operations. We create Var `a` and `b` via operation `jt.float32`, and add them. Printing those variables shows they have the same shape and dtype.
diff --git a/README.src.md b/README.src.md
index 1277bcfc..3fbdb14a 100644
--- a/README.src.md
+++ b/README.src.md
@@ -322,7 +322,7 @@ print(c.name())
 # Output: c
 ```
 
-###Operations
+### Operations
 
 ### 数据运算
 
diff --git a/python/jittor_utils/__init__.py b/python/jittor_utils/__init__.py
index 710a25c3..09f381c0 100644
--- a/python/jittor_utils/__init__.py
+++ b/python/jittor_utils/__init__.py
@@ -129,9 +129,17 @@ def do_compile(args):
         run_cmd(cmd)
         return True
 
+pool_size = 0
+
 def run_cmds(cmds, cache_path, jittor_path):
+    global pool_size
+    if pool_size == 0:
+        mem_bytes = os.sysconf('SC_PAGE_SIZE') * os.sysconf('SC_PHYS_PAGES')
+        mem_gib = mem_bytes/(1024.**3)
+        pool_size = min(8,max(int(mem_gib // 3), 1))
+        LOG.i(f"Total mem: {mem_gib:.2f}GB, using {pool_size} procs for compiling.")
     cmds = [ [cmd, cache_path, jittor_path] for cmd in cmds ]
-    with Pool(8) as p:
+    with Pool(pool_size) as p:
         p.map(do_compile, cmds)
 
 def download(url, filename):
diff --git a/setup.py b/setup.py
index 0e530b59..e57c69ab 100644
--- a/setup.py
+++ b/setup.py
@@ -21,7 +21,7 @@ with open(os.path.join(path, "README.md"), "r", encoding='utf8') as fh:
 
 setuptools.setup(
     name='jittor',  
-    version='1.1.2',
+    version='1.1.3',
     # scripts=[],
     author="Jittor Group",
     author_email="ran.donglang@gmail.com",