Postgres not able to start

I have a problem with postgres not being able to start:

• Starting PostgreSQL 9.5 database server * The PostgreSQL server failed to start. Please check the log output: 2016-08-25 04:20:53 EDT [1763-1] FATAL: could not map anonymous shared memory: Cannot allocate memory 2016-08-25 04:20:53 EDT [1763-2] HINT: This error usually means that PostgreSQL’s request for a shared memory segment exceeded available memory, swap space, or huge pages. To reduce the request size (currently 1124007936 bytes), reduce PostgreSQL’s shared memory usage, perhaps by reducing shared_buffers or max_connections. This is the response that I got. I checked the log in tail -f /var/log/postgresql/postgresql-9.5-main.logand I can see the same response.

Can someone suggest what can be the problem?

I used following commands to stop/start the postgres server on Ubuntu 14.04 with postgres 9.5:

sudo service postgresql stop sudo service postgresql start