Systems and methods for adaptive credit-based flow
View Patent ↗The present invention relates generally to an information handling system. Aspects of the present invention include an adaptive credit-based flow control in an information handling system. In embodiments, a request/grant credit system can be eliminated since the receiver can dynamically allocate credits based on demand at the sender. In embodiments, the sender can provide information related to its queue size to the receiver. The receiver can estimate queue size and demand based on the estimated queue size. In embodiments, the receiver allocates credits based on sender demand.
1. An information handling system (IHS), the system comprising:
a plurality of input/output (I/O) ports, which facilitate communications with one or more devices that are communicatively coupled to the IHS;
a data processing component that processes data traffic via at least one of the plurality of I/O ports;
an amount of fixed buffer that corresponds with a particular port in the plurality of I/O ports;
a demand estimator that determines demand; and
a shared buffer pool at least a portion of which is dynamically allocated to at least one of the plurality of ports based at least in part on at least a portion of the determined demand and availability of buffer credits in the shared buffer pool;
the IHS being configured:
when operating as a sender, to determine an amount of available buffer credit and send data traffic based on having buffer credit available, the IHS as the sender also having a queue size representing a size of data traffic that has not been sent and is ready to send; and
when operating as a receiver, to receive information from a second IHS operating as a sender, the receiver also determines demand based on a queue size associated with second IHS and available buffer credit at the second IHS.
2. The system of claim 1 wherein the queue size is an estimate of a raw queue size.
3. The system of claim 1 wherein the queue size is an estimate of the rate of change of the queue size.
4. The system of claim 1 wherein the shared buffer pool is proportionally dynamically allocated based on the determined demand is based at least in part upon demand of another information handling system that is communicatively coupled to the information handling system estimate and the availability of credits in the shared buffer pool.
5. The system of claim 1 , wherein the shared buffer pool is dynamically allocated based on amount of availability of fixed buffer credit.
6. The system of claim 1 wherein the shared buffer pool is dynamically allocated based on allocation and consumption of the shared buffer pool.
7. The system of claim 1 wherein the IHS when operating as a sender further provides information related to queue size to a receiver node responsive to the queue size crossing a predetermined threshold value.
8. The system of claim 1 wherein the IHS when operating as a sender further automatically provides information about queue size to a receiver node at a predetermined periodic interval.
9. A receiver information handling system (IHS), the receiver IHS comprising:
a plurality of input/output (I/O) ports configured to receive data traffic from a peer IHS;
a peer queue size estimator configured to automatically receive data related to a queue size of the peer IHS and estimates a peer queue size using the received data related to the queue size of the peer IHS;
a memory management unit comprising:
a fixed memory buffer configured to permit the receiver IHS to grant a buffer credit to the peer IHS; and
a shared buffer pool configured to permit the receiver IHS to allocate buffer space from the shared buffer pool across the plurality of ports at the receiver IHS based on at least part of the estimated peer queue size and availability of buffer credits in the shared buffer pool; and
a scheduler that grants one or more buffer credits to the peer IHS.
10. The node of claim 9 wherein the scheduler runs periodically to grant a one or more buffer credits to the peer IHS.
11. The node of claim 10 wherein the plurality of ports are configured to use one or more classes of traffic.