[default]
callback_whitelist = profile_tasks
# The best way I’ve found to time the execution of Ansible playbooks is by enabling the profile_tasks callback. This callback is included with Ansible and all you need to do to enable it is add callback_whitelist = profile_tasks to the [defaults] section of your ansible.cfg:

[ssh_connection] 
ssh_args 
 
= -o ControlMaster=auto -o ControlPersist=60s
#The first thing to check is whether SSH multiplexing is enabled and used. This gives a tremendous speed boost because Ansible can reuse opened SSH sessions instead of negotiating new one (actually more than one) for every task. Ansible has this setting turned on by default. It can be set in
 
 configuration file as follows:

[ssh_connection]
pipelining = True
# You can enable pipelining by simply adding pipelining = True to the [ssh_connection]area of your ansible.cfg or by by using the ANSIBLE_PIPELINING and ANSIBLE_SSH_PIPELINING environment variables.

[defaults]
strategy_plugins = /path/to/mitogen-0.2
 
.5/ansible_mitogen/plugins/strategy
strategy = mitogen_linear
# Enabling Mitogen for Ansible is as simple as downloading and extracting the plugin, then adding 2 lines to the [defaults] section of your ansible.cfg

[ssh_connection]
ssh_args = -o ControlMaster=auto -o ControlPersist=60s -o PreferredAuthentications=publickey
#PreferredAuthentications  It is an SSH-client setting which informs server about preferred authentication methods. By default Ansible uses: -o PreferredAuthentications=gssapi-with-mic,gssapi-keyex,hostbased,publickey

[defaults]
forks = 20

[defaults]
internal_poll_interval = 0.001
#When module is executed on remote host, Ansible starts to poll for its result. The lower is interval between poll attempts, the higher is CPU load on Ansible control host. But we want to have CPU available for greater forks number (see above). You can tweak poll interval in  ansible.cfg

gathering = smart
fact_caching_timeout = 86400
fact_caching = jsonfile
fact_caching_connection = /dev/shm/ansible_fact_cache