US 8,429,661 B1Granted

Managing multi-threaded FIFO memory by determining whether issued credit count for dedicated class of threads is less than limit

AssigneeNVIDIA Corporation

InventorsRobert A. Alfieri, Marcio T. Oliveira

Life of this patent

Estimating the term…

Loading patent…

Abstract

Systems and methods storing data for multi-threaded processing permit multiple execution threads to store data in a single first-in first-out (FIFO) memory. Threads are assigned to classes, with each class including one or more threads. Each class may be allocated dedicated entries in the FIFO memory. A class may also be allocated shared entries in the FIFO memory. The shared entries may be used by any thread. Data for a first thread may be stored in the FIFO memory while data for a second thread is read from the FIFO memory, even when the first thread and the second thread are not in the same class. The FIFO memory is shared between the threads to conserve die area, however each thread may be executed independently, as if each thread has a dedicated FIFO memory.

Claims18

Dependent claims

A method of storing data for a plurality of threads in a FIFO (first-in first-out memory) storage, the method comprising:

determining whether an issued credit count for a dedicated class of threads is less than a first limit value;
if the issued credit count is less than the first limit value, then issuing a sender credit for the dedicated class of threads to a sender indicating that an entry is available in the FIFO storage for data that is to be processed by a thread included in the dedicated class of threads;
if the issued credit count is not less than the first limit value, then issuing a sender credit for a shared class of threads to the sender indicating that an entry is available in the FIFO storage for data that is to be processed by a thread included in the shared class of threads, wherein a first number of entries in the FIFO storage are allocated to the shared class of threads that includes the plurality of threads, and a second number of entries in the FIFO storage are allocated to the dedicated class of threads, wherein the dedicated class of threads includes only a portion of the plurality of threads;
receiving first data from the sender;
obtaining a pointer to an entry in the FIFO storage from a free pointer list that includes pointers to available entries in the FIFO storage;
storing the first data in the entry in the FIFO storage;
storing the pointer in an ordered list of pointers;
and
outputting a receiver credit to a receiver indicating that the first data for the first thread is stored in the FIFO storage.

6 more elements

A system for storing data for a plurality of threads, comprising:

a sender interface configured to receive data that is to be processed by the plurality of threads and further configured to output a receiver credit to a receiver indicating that the data is stored in the FIFO storage;
a FIFO (first-in first-out memory) storage coupled to the sender interface and configured to store the data, wherein a first number of entries in the FIFO storage are allocated to a shared class of threads that includes the plurality of threads and a second number of entries in the FIFO storage are allocated to a dedicated class of threads that includes only a portion of the plurality of threads, wherein the sender interface is configured to:
determine whether an issued credit count for the dedicated class of threads is less than a first limit value;
if the issued credit count is less than the first limit value, then issue a sender credit for the dedicated class of threads to a sender indicating that an entry is available in the FIFO storage for data that is to be processed by a thread included in the dedicated class of threads;
if the issued credit count is not less than the first limit value, issue a sender credit for the shared class of threads to the sender indicating that an entry is available in the FIFO storage for data that is to be processed by a thread included in the shared class of threads;
a receiver interface coupled to the FIFO storage and configured to output the data from the FIFO storage;
and
a read and write control unit configured to maintain an ordered pointer list and coupled to the FIFO storage, the ordered pointer list including free pointers corresponding to entries in the FIFO storage that are available to store the data in a first portion and pointers corresponding to entries in the FIFO storage that are not available in a second portion.

5 more elements

Dependencies are inferred from the claim text.