diff --git a/.gitmodules b/.gitmodules
index 0f8368b..38fdbd6 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,6 +1,9 @@
 [submodule "nfs"]
 	path = roles/nfs
 	url = https://github.com/geerlingguy/ansible-role-nfs.git
 [submodule "roles/jenkins"]
 	path = roles/jenkins
 	url = https://github.com/ICTO/ansible-jenkins.git
+[submodule "roles/swap"]
+	path = roles/swap
+	url = https://github.com/tribou/ansible-swap.git
diff --git a/README.md b/README.md
index 0984d2b..21f1688 100644
--- a/README.md
+++ b/README.md
@@ -1,50 +1,65 @@
 C4SCIENCE
 =========
 
 * Ansible playbook for git infrastructure on openstack
 
 INSTALL
 -------
 
 * You need ansible >= 2.0
 
 ```
 cd ~
 git clone https://github.com/ansible/ansible.git
 cd ansible
 git submodule update --init --recursive
 sudo python setup.py install
 sudo pip install shade 
 sudo apt-get install python-nova
 ```
 
 USAGE
 -----
 
 * How to use,
 
 ```
   make status #list instances
   make up #create instances
   make clean #destroy instances
 ```
 
 * You must create an Switch Engines bucket
     * see https://help.switch.ch/engines/documentation/s3-like-object-storage/
 
 ```
   ./s3cmd mb s3://phabricator
 ```
 
 * you must create a volume for the repo, and attach it to the jump server
 
 ```
     nova volume-create 100
     nova volume-attach <server> <volume> /dev/vdb
 ```
 
 TODO
 ----
 
 * Shibboleth auth
 * Volumes for /var/lib/mysql
+
+TEST
+----
+
+* Some benchmarking examples,
+
+```
+# GIT
+cd /tmp
+parallel -j 10 git clone ssh://git@86.119.28.215:1234/diffusion/TESTA/test.git \
+    -- $(for i in $(seq 20); do echo test$i; done) 1> /dev/null
+# HTTP
+ab -C phsid:cz27psxxn2zjxtkw4v2tokhbjy4ix2lrifj6exm3 -C phusr:admin -n 1000 \
+    -c 10 http://86.119.28.215/diffusion/TESTA/repository/master/
+```
diff --git a/main.yml b/main.yml
index 279f8a4..59474f0 100644
--- a/main.yml
+++ b/main.yml
@@ -1,69 +1,79 @@
 ---
 - name: Create Instances
   hosts: 127.0.0.1
   connection: local
   gather_facts: false
   vars_files:
     - "vars/main.yml"
   tasks:
     - include: tasks/create-instances.yml
 
 - name: Configure Jump Server
   hosts: lbs 
   vars_files:
     - "vars/main.yml"
+    - "vars/swap.yml"
   user: centos
   sudo: yes
   pre_tasks:
       #- debug: var=hostvars['127.0.0.1']['openstackjump']['private_ip'][0]
     - include: tasks/common.yml
     - include: tasks/configure-jump.yml
   roles:
+      - role: swap/roles/swap
       - role: nfs
         nfs_server_daemon: nfs-server # doesn't work as it's in vars not default
   handlers:
     - include: handlers/main.yml
 
 - name: Configure Databases
   hosts: dbs
   vars_files:
     - "vars/main.yml"
+    - "vars/swap.yml"
   user: centos
   sudo: yes
+  roles:
+      - role: swap/roles/swap
   tasks:
     - include: tasks/common.yml
     - include: tasks/configure-dbs.yml
   handlers:
     - include: handlers/main.yml
 
 - name: Configure App
   hosts: app
   vars_files:
     - "vars/main.yml"
+    - "vars/swap.yml"
   user: centos
   sudo: yes
+  roles:
+      - role: swap/roles/swap
   tasks:
     - include: tasks/common.yml
     - include: tasks/configure-app.yml
   handlers:
     - include: handlers/main.yml
 
 #- name: Configure Jenkins
 #  hosts: ci
 #  vars_files:
 #    - "vars/main.yml"
+#    - "vars/swap.yml"
 #  user: centos
 #  sudo: yes
 #  tasks:
 #    - include: tasks/common.yml
 #  roles:
+#      - role: swap/roles/swap
 #      - role: jenkins
 #        plugins:
 #          - 'ldap'
 #          - 'preSCMbuildstep'
 #        prefix: '/build'
 #        email:
 #          smtp_host: 'mail.epfl.ch'
 #          smtp_ssl: 'true'
 #          default_email_suffix: '@epfl.ch'
 #
diff --git a/roles/swap b/roles/swap
new file mode 160000
index 0000000..801a751
--- /dev/null
+++ b/roles/swap
@@ -0,0 +1 @@
+Subproject commit 801a751ce4f8a99804f20dbe4aba4e64c5f1e5b8
diff --git a/vars/swap.yml b/vars/swap.yml
new file mode 100644
index 0000000..f1141f7
--- /dev/null
+++ b/vars/swap.yml
@@ -0,0 +1,21 @@
+---
+# All ansible-swap variables
+# Override any in your local ansible group_vars/swap.yml
+
+# Location of swapfile
+swap_path: "/swapfile"
+
+# Hosts with low RAM may need to use a small bs size
+dd_bs_size_mb: 32
+
+# Total size for swapfile
+# Count of how many passes dd should make at bs size
+swap_count: 128
+
+# 0 to 100, how often swap is utilized
+# 60 is good for desktops, 10 is good for VPS
+swappiness: 10
+
+# How often inode info is removed from cache
+# Usually a frequent and costly lookup if not cached
+vfs_cache_pressure: 50