Apache – Invalid command ‘SSLMutex’

I am in the process of upgrading Apache version from 2.0 to 2.4. After 2.4 installed, I have faced below issue.

Invalid command 'SSLMutex', perhaps misspelled or defined by a module not included in the server configuration
AH00526: Syntax error on line 77 of /apache/conf/ssl.conf:

The line #77 in ssl.conf is SSLMutex file:/apache/logs/ssl_mutex.

I have loaded mod_ssl and along with I have loaded below mod also but still I could not fix this.

LoadModule authn_core_module modules/mod_authn_core.so
LoadModule authz_core_module modules/mod_authz_core.so
LoadModule socache_dbm_module modules/mod_socache_dbm.so
LoadModule socache_shmcb_module modules/mod_socache_shmcb.so

NOTE: If I comment out the SSLMutex line in ssl.conf file then Apache is working including SSL port. I am afraid what will happen if SSLMutex issue is not resolved. Please suggest some solution.

thanks