git instaweb --httpd=webrick - error

I have two repository, for one i had ran git instaweb --httpd=webrick for web access, when i try to run for second i'm getting below error. I will be hosting six repo in one server, how to handle this.

ERROR --> 
/usr/lib/ruby/1.8/webrick/utils.rb:73:in `initialize': Address already in use - bind(2) (Errno::EADDRINUSE)
        from /usr/lib/ruby/1.8/webrick/utils.rb:73:in `new'
        from /usr/lib/ruby/1.8/webrick/utils.rb:73:in `create_listeners'
        from /usr/lib/ruby/1.8/webrick/utils.rb:70:in `each'
        from /usr/lib/ruby/1.8/webrick/utils.rb:70:in `cre开发者_开发百科ate_listeners'
        from /usr/lib/ruby/1.8/webrick/server.rb:75:in `listen'
        from /usr/lib/ruby/1.8/webrick/server.rb:63:in `initialize'
        from /usr/lib/ruby/1.8/webrick/httpserver.rb:24:in `initialize'
        from /home/gitadmin/sdk.git/gitweb/webrick.rb:20:in `new'
        from /home/gitadmin/sdk.git/gitweb/webrick.rb:20
Could not execute http daemon webrick.

The port is already in use by the first repo. You'll either have to specify a different port (using the --port argument to git instaweb), or use another solution. Git instaweb isn't really designed for serving multiple repos, though; you probably want to use git daemon to serve the repos and Gitweb to browse them. Both are available as part of core Git.