User Guide

  • 2020
  • 06/18/2020
  • Public Content
Contents

Retire Stalls

Metric Description

This metric is defined as a ratio of the number of cycles when no micro-operations are retired to all cycles. In the absence of performance issues, long latency operations, and dependency chains, retire stalls are insignificant. Otherwise, retire stalls result in a performance penalty. On processors based on the Intel microarchitecture code name Nehalem, this metric is based on precise events that do not suffer from significant skid.

Possible Issues

A high number of retire stalls is detected. This may result from branch misprediction, instruction starvation, long latency operations, and other issues. Use this metric to find where you have stalled instructions. Once you have located the problem, analyze metrics such as LLC Miss, Execution Stalls, Remote Accesses, Data Sharing, and Contested Accesses, or look for long-latency instructions like divisions and string operations to understand the cause.

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804