Performance applications that use Hardware Performance Monitoring Counters do not display information correctly

Products

• VMware Desktop Hypervisor
• VMware vSphere ESXi

Issue/Introduction

Symptoms:
When using applications that rely on Hardware Performance Monitoring Counters, such as the Linux application perf, you experience these symptoms:

• The performance counter data does not display correctly.
• The performance counter data is incorrect.
• The performance counter data is absent from the command output.

Environment

VMware ESX 4.0.x
VMware ESX Server 3.5.x
VMware ESXi 3.5.x Embedded
VMware ESX Server 2.0.x
VMware ESXi 4.0.x Embedded
VMware ESX Server 3.0.x
VMware ESXi 3.5.x Installable
VMware vSphere ESXi 5.0
VMware ESX Server 1.x
VMware ESXi 4.1.x Installable
VMware ESXi 4.0.x Installable
VMware ESX 4.1.x
VMware ESX Server 2.5.x
VMware ESXi 4.1.x Embedded
VMware ESX Server 2.1.x
VMware ESX Server 1.5.x

Cause

This issue occurs because the Hardware Performance Monitoring Counters (HW PMCs) are not interpreted in VMware virtualization products. This can cause any application that calls on the HW PMCs to display incorrect data or fail to display the counter metrics at all.

Resolution

The virtualized HW PMC features are not currently available in ESXi/ESX, VMware Workstation, and VMware Fusion.

To work around this issue, use a performance monitoring utility that does not require the use of Hardware Performance Monitoring Counters. Read the technical documentation with your performance monitoring applications to determine if HW PMCs are required.

Additional Information

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Impact/Risks:

HW PMCs may provide a layer of performance data not visible by conventional performance monitoring utilities. However, there is a risk of inaccurate data reporting being provided by utilities using HW PMCs where they are not supported. Therefore, avoid using any application that uses HW PMCs until this feature is enabled and supported on your chosen VMware virtualization product.