International Business Machines Corporation
Uncore input/output latency analysis

Abstract:

A computing system includes a core system and an uncore system. The core system includes a packet generator unit configured to generate a data packet having a plurality of bytes defining a target packet size, and to output a first byte among the plurality of bytes at a packet delivery start time. The uncore system includes an input/output (I/O) bridge configured to connect an I/O component to the core system, and a packet monitor unit configured to monitor the bytes delivered from the packet generator unit to the I/O component. The packet monitor unit further determines a packet delivery end time after detecting a last byte of the data packet. The computing system determines a latency attributed to the uncore system and the I/O bridge based on the packet delivery start time and the packet delivery end time.