A translation look-aside buffer (TLB) has lockable entries. A number of entries to lock may be determined by counting unique page access instances during an active period of a process, determining a value of a page usage metric for the process, and comparing the value of the page usage metric to values of page usage metrics for other processes. The page usage metric may consider many different factors, including the amount of time a process is active, a frequency of invocation of the process, and a priority level of a process.