MySQL cannot start--cannot allocate the memory for the buffer pool

2017-08-13 13:40:27 19011 [Note] innodb:initializing buffer pool, size = 128.0M
Innodb:mmap (137363456 bytes) failed; errno 12
2017-08-13 13:40:27 19011 [ERROR] InnoDB: cannot allocate memory for the buffer pool
2017-08-13 13:40:27 19011 [ERROR] Plugin ' InnoDB ' init function returned ERROR.
2017-08-13 13:40:27 19011 [ERROR] Plugin ' InnoDB ' registration as a STORAGE ENGINE failed.
2017-08-13 13:40:27 19011 [ERROR] unknown/unsupported storage Engine:innodb
2017-08-13 13:40:27 19011 [ERROR] Aborting
# free-m found Insufficient memory

Workaround:

Add the following fields in MY.CNF

innodb_buffer_pool_size=200m
key_buffer=120m

MySQL cannot start--cannot allocate the memory for the buffer pool