1. A method for providing an extendable job structure for executing instructions on an accelerator, the method comprising: receiving, by a processing device, a number of data descriptor blocks, wherein each of the number of data descriptor blocks comprises memory location addresses for data associated with each of the number of data descriptor blocks and a pointer to a next of the number of the data descriptor block; receiving a last data descriptor block comprising memory location addresses for data associated with last data descriptor block and an last block indicator, wherein one of the pointers to the next of the number of the data descriptor blocks points to the last data descriptor block; based on determining that additional memory is required for executing instructions on the accelerator: modifying the last data descriptor block to become a data extender block comprising a pointer to one of one or more new data descriptor blocks, each of the one or more new data descriptor blocks comprises memory location addresses for data; and creating a new last data descriptor block comprising memory locations for data associated with the new last data descriptor block and the last block indicator.