A method and system for maintaining a pinned kernel memory pool from which memory buffers are allocated to time critical processing tasks. The memory pool initially comprises a base block of pinned kernel memory to which additional memory blocks are added as more buffers are requested. Non-contiguous memory blocks may be used because they are maintained as a linked list. New buffer requests are satisfied from the earliest added blocks. The most recently added memory blocks are periodically examined for use to determine if they are in use and are returned to the kernel memory pool if they are unused.