Caching a memory descriptor for plural input/output requests

A method, implemented at a computer system that includes a processor, for caching a memory descriptor across a plurality of input/output (I/O) requests, the method comprising:

• creating a memory descriptor that describes a layout of a set of physical memory pages assigned to a buffer, the creating the memory descriptor including assigning and locking the set of physical memory pages to the memory descriptor;
• receiving a plurality of I/O requests on the buffer;
• for each I/O request of the plurality of I/O requests on the buffer:
• returning at least a subset of the memory descriptor for use by the I/O request, and
• using a reference count to track the I/O request as being pending on the memory descriptor;
• releasing the memory descriptor, including unlocking the set of physical memory pages, based at least on the reference count indicating that there is no pending I/O request on the memory descriptor;
• and
• based at least on receiving a request from a buffer consumer to register the buffer:
• creating a buffer entry data structure that includes a starting address and a buffer length for the buffer;
• and
• inserting the buffer entry data structure into a buffer entry list.

A computer system for caching a memory descriptor across a plurality of input/output (I/O) requests, comprising:

• a processor;
• and
• a computer storage media that stores computer-executable instructions that are executable by the processor to cause the computer system to at least:
• receive a request from a buffer consumer to register a buffer;
• create a memory descriptor that describes a layout of a set of physical memory pages assigned to the buffer, creating the memory descriptor including assigning and locking the set of physical memory pages to the memory descriptor;
• receive a plurality of I/O requests on the buffer;
• for each I/O request of the plurality of I/O requests on the buffer:
• return at least a subset of the memory descriptor for use by the I/O request, and
• use a reference count to track the I/O request as being pending on the memory descriptor;
• and
• release the memory descriptor, including unlocking the set of physical memory pages, based at least on the reference count indicating that there is no pending I/O request on the memory descriptor, wherein:
• an I/O request of the plurality of I/O requests comprises an offset and length identifying a subset of the buffer, and wherein returning at least the subset of the memory descriptor for use by the I/O request comprises returning a partial memory descriptor corresponding to the offset and length;
• or
• an I/O request of the plurality of I/O requests comprises an offset and length identifying an entirety of the buffer, and wherein returning at least the subset of the memory descriptor for use by the I/O request comprises returning the memory descriptor in its entirety.