How can I disable "cache: [GET /] miss" logs?

When I deployed my rails 3.2.1 app in production mode, I saw a lot of
entries like:
cache: [GET /] miss
cache: [GET //] miss

I would like to disable logging these entries.

My config/environments/production.rb did not have config.log_level
specified. So it should be :info by default. I tried config.log_level

:error, but it still spit out those log entries. How can I disable
while keeping other logs for errors and fatals?

Thanks for your help.