Transaction re-ordering

An apparatus comprising:

• a root controller configured to:
• receive a plurality of transactions over a point-to-point PCIe-compliant interconnect, wherein the root controller includes an I/O module including a protocol stack including a transaction layer, a link layer, and a physical layer, and the plurality of transactions include transaction layer packets each including a transaction layer header, and wherein the plurality of transactions are to be received in a first order, a particular one of the plurality of transactions follows another one of the plurality of transactions in the first order, and the plurality of transactions includes a subset of transactions each referencing a particular memory location;
• identify that relaxed ordering applies to the particular transaction based at least in part on a value of an ordering attribute field of the particular transaction, wherein the ordering attribute field comprises a single bit;
• and
• reorder at least the particular transaction in the plurality of transactions, wherein the plurality of transactions are in a different second order following the reordering, the particular transaction precedes the other transaction in the second order, the reordering allows the particular transaction to be completed prior to the other transaction, and priority of transactions is the subset of transactions, as defined in the first order, is to be maintained in the second order.

A method comprising:

• receiving a plurality of transactions over a PCIe-compliant interconnect, wherein the plurality of transactions are received in a first order;
• identifying a relaxed ordering value included in at least one of the plurality of transactions;
• identifying that a subset of the plurality of transactions each reference a particular memory location;
• and
• reordering the plurality of transactions into a second, different order based at least in part on the relaxed ordering value, wherein the plurality of transactions are in a second order following the reordering and priority of the subset of transactions in the first order is maintained in the second order.

A system comprising:

• a first device;
• a second device, including an I/O module executed by at least one processor to:
• receive a plurality of transactions over a PCIe-compliant interconnect, wherein the plurality of transactions are received in a first order and at least one of the transactions is requested by the first device;
• identify a relaxed ordering value included in at least one of the plurality of transactions;
• identify that a subset of the plurality of transactions each reference a particular memory location;
• reorder the plurality of transactions into a second, different order based at least in part on the relaxed ordering value, wherein the plurality of transactions are in a second order following the reordering and priority of the subset of transactions in the first order is maintained in the second order;
• and
• cause the plurality of transactions to be completed according to the second order.