Dynamically allocating limited system memory for DMA among multiple adapters
AssigneeInternational Business Machines Corporation
InventorsColin R. DeVilbiss, Wayne G. Holm, David B. Murray, Kristopher C. Whitney
Life of this patent
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Abstract
A method, apparatus, and computer program product dynamically allocate limited system memory for direct memory access (DMA) among a plurality of input/output (I/O) adapters in a system partition. Initially a minimum entitlement of I/O entitled memory capacity is allocated to each of the respective multiple I/O adapters. The minimum entitlement enables operation of an I/O adapter driver. Additional entitlement of I/O entitled memory capacity is selectively allocated based upon I/O demands of each I/O adapter.
Claims20
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.
A computer-implemented method for dynamically allocating limited system memory for direct memory access (DMA) among multiple I/O adapters in a system partition, said method comprises the steps of:
- using a free memory pool and managing I/O entitled memory capacity assigned to the system partition, initially assigning 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 an I/O adapter driver;
- managing I/O entitled memory for each respective I/O adapter, allowing unused entitlement allocated to the respective I/O adapter driver to be returned to a free memory pool;
- and allowing an amount of the entitlement allocated to be increased due to I/O demand;
- and
- selectively allocating additional entitlement of I/O entitled memory capacity based upon I/O demands of each respective I/O adapter.
A computer program product embodied on a computer readable storage medium for dynamically allocating limited system memory for direct memory access (DMA) among multiple I/O adapters in a computer system, said computer readable storage medium storing instructions, and said instructions when executed by the computer system cause the computer system to perform the steps comprising:
- using a free memory pool and managing I/O entitled memory capacity assigned to a system partition, 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 an I/O adapter driver;
- managing I/O entitled memory for each respective I/O adapter, allowing unused entitlement allocated to the respective I/O adapter driver to be returned to a free memory pool;
- and allowing an amount of the entitlement allocated to be increased due to I/O demand;
- and
- selectively allocating additional entitlement of I/O entitled memory capacity based upon I/O demands of each respective I/O adapter.
Dependencies are inferred from the claim text.