Roll in may refer to any of the following:
1. With data, roll in describes restoring data (e.g., files or programs) that were rolled out to an auxiliary storage or secondary storage back to the primary storage. For example, moving data from virtual memory on the hard drive back into RAM (random-access memory).
2. With the IBM Series/1, the term roll in describes restoring a task set that had been previously rolled out. A roll in occurs when a task set has the highest queue priority.