Patent ID: 8135934

Claim:
An apparatus for dynamically allocating limited system memory for direct memory access (DMA) among multiple I/O adapters in a system partition comprising: a partition entitlement manager using a free memory pool and managing I/O entitled memory capacity assigned to the system partition, said partition entitlement manager embodied in a non-transitory machine readable medium, said partition entitlement manager initially allocating a minimum entitlement of said I/O entitled memory capacity to each of the respective multiple I/O adapters, said minimum entitlement enabling operation of each respective I/O adapter driver; a respective quota managing I/O entitled memory for each respective I/O adapter; said quota embodied in a non-transitory machine readable medium, said respective quota allowing unused entitlement allocated to the respective I/O adapter driver to be returned to said free memory pool; said respective quota allowing an amount of the entitlement allocated to be increased due to I/O demand; and said partition entitlement manager selectively allocating additional entitlement of I/O entitled memory capacity based upon I/O demands of each respective I/O adapter.