Computer Dictionary of Information Technology

first fit

A resource allocation scheme that searches a list of free resources and returns the first one that can satisfy the request.

For example, when allocating memory from a list of free blocks (a heap), first fit scans the list from the beginning until it finds a block which is big enough to satisfy the request. The requested size is allocated from this block and the rest of the block returned to the free pool.

First fit is faster than a best fit scheme, but results in more fragmentation of the free space because it is more likely to split up a large free block when a smaller block could have been used.