Introduction to Windows Performance Analyzer (WPA)

The Windows Performance Analyzer (WPA) is a powerful tool for in-depth analysis of system and application performance. It allows developers and system administrators to capture detailed performance traces using Event Tracing for Windows (ETW) and then visualize and analyze this data to identify performance bottlenecks, diagnose issues, and optimize system behavior.

WPA is part of the Windows ADK (Assessment and Deployment Kit) and provides a rich set of visualizations and analytical capabilities, including CPU usage, disk I/O, memory consumption, application responsiveness, and more.

Getting Started with WPA

This section guides you through the initial steps to start using WPA effectively.

Downloading WPA

WPA is included in the Windows Performance Toolkit, which is a component of the Windows ADK. You can download the latest version from the official Microsoft website: Download Windows ADK

Installation

During the Windows ADK installation, select "Windows Performance Toolkit" to install WPA and related tools.

Collecting Performance Data (.etl files)

Performance data is typically collected using tools like Windows Performance Recorder (WPR) or `xperf`. WPR is generally recommended for most scenarios due to its user-friendly interface.

Example using WPR command-line:

wpr.exe -start GeneralProfile -filemode c:\perf_data.etl -start CPU -start Disk -start FileIO -start Power

To stop recording:

wpr.exe -stop c:\perf_data.etl

Opening WPA and Loading Data

Launch Windows Performance Analyzer. You will be prompted to open a trace file. Select your recorded .etl file. WPA will then process the data and present it for analysis.

Once the trace is loaded, WPA populates the "Analysis" pane with various analysis modules.

Key Features of WPA

WPA offers a comprehensive set of features for performance analysis.

Graph Pane

The Graph Pane is where you visualize time-series data. You can add various graphs to represent metrics like CPU usage, disk I/O operations, context switches, and more. Graphs can be stacked, overlaid, and zoomed for detailed examination.

Table Pane

The Table Pane displays aggregated or detailed data in a tabular format. This is useful for viewing statistics, identifying top consumers of resources, or examining specific events. You can configure columns to display relevant information.

Filtering and Sorting

WPA provides robust filtering and sorting capabilities. You can filter data based on process name, thread ID, event type, time range, and many other criteria. Sorting allows you to quickly identify the most significant contributors to performance issues.

Bookmarks and Regions

You can mark specific time intervals (regions) in your trace for later reference or to isolate problematic periods. Bookmarks are invaluable for documenting findings or sharing specific parts of a trace with colleagues.

Analysis Reports

WPA can generate summary reports that highlight potential performance issues and provide recommendations. These reports can be a good starting point for deeper investigation.

Common Analysis Scenarios

WPA is used to diagnose a wide range of performance problems.

CPU Usage Analysis

Analyze CPU utilization by process, thread, or function. Identify hot spots, CPU contention, and inefficient code paths. Key graphs include "CPU Usage (Precise)" and "CPU Usage (Sampled)".

Disk I/O Analysis

Investigate disk read/write activity. Understand which processes are performing the most I/O, identify latency issues, and diagnose storage bottlenecks. Examine graphs like "Disk I/O" and "File I/O".

Memory Usage Analysis

Monitor memory allocation, page faults, and garbage collection activity. WPA helps in identifying memory leaks or excessive memory consumption. Look into "Memory" and "VirtualAlloc" graphs.

Application Responsiveness

Analyze application startup times, UI thread blocking, and overall system responsiveness. WPA's "Application Response Analysis" provides insights into user experience.

Advanced Topics

Explore advanced features such as creating custom analysis configurations, scripting WPA analysis, and integrating with other development tools. Advanced users can delve into specific ETW providers and event data for fine-grained analysis.

Troubleshooting

Common issues include trace file corruption, missing symbols, and performance overhead during data collection. Ensure symbol paths are correctly configured in WPA and use appropriate recording profiles to minimize impact. Consult official Microsoft documentation for detailed troubleshooting guides.