Abstract: A system and methods are provided for inserting probe points into an executing program, and measuring the time spent traversing code paths from one probe point to any other probe point or some other performance metric (e.g., instructions executed, cache misses, memory addresses accessed). One method is implemented by inserting N probes. Each probe has a corresponding function configured to: retrieve the identifier and timestamp of the previous probe executed, calculate the time spent traversing the path from the previous probe to the current probe, and update a matrix of N×N elements, wherein each element corresponds to a path from one probe to another probe. After completion of the program, this matrix is useful for identifying code paths that are bottlenecks and hence candidates for optimization.

Abstract: A system and method for reclaiming descriptors in a separate process (e.g., thread) from one in which packets are posted to a descriptor ring. The packet-posting process need not be interrupted to reclaim used descriptors, thereby reducing the delay in transmitting packets through a communication interface. The descriptor reclamation process, which may execute on a separate processor from the packet-posting process, may remain quiescent as long as the ring is less than half full or there are no descriptors to reclaim. Then, both processes may operate in parallel.

Abstract: A system and methods are provided for inserting probe points into an executing program, and measuring the time spent traversing code paths from one probe point to any other probe point or some other performance metric (e.g., instructions executed, cache misses, memory addresses accessed). One method is implemented by inserting N probes. Each probe has a corresponding function configured to: retrieve the identifier and timestamp of the previous probe executed, calculate the time spent traversing the path from the previous probe to the current probe, and update a matrix of N×N elements, wherein each element corresponds to a path from one probe to another probe. After completion of the program, this matrix is useful for identifying code paths that are bottlenecks and hence candidates for optimization.