IdleWakeups

IdleWakeups detects idle wakeups in Chrome (using an ETW trace) and exports symbolized callstacks related to these wakeups into a gzip-compressed protocol buffer.

It uses the .NET TraceProcessing API to process ETW traces.

This tool was built for processing ETW traces from Chrome, so the default values of the flags are based on that use case. It uses _NT_SYMCACHE_PATH and _NT_SYMBOL_PATH for symbolizing traces if set, otherwise it uses WPA defaults.

See this blog post for details of the Trace Processor package used to drive this.

More explanations of the techniques used in this program can be found here.

The style and structure of this project is inspired by work in EtwToPprof.

Building

Build the provided Visual Studio Solution with VS 2022.

NuGet dependencies (included in solution)

• CommandLineParser v2.8.0
• Microsoft.Windows.EventTracing.Processing.All v1.9.2
• Google.Protobuf v3.19.3

Examples

Export idle wakeup callstacks found in trace.etl to specified pprof profile using default options:

IdleWakeups -o profile.pb.gz trace.etl

Export idle wakeup callstacks from all processes from 20s to 30s to default pprof profile:

IdleWakeups -p * --timeEnd 30 --timeStart 20 trace.etl

Export idle wakeup callstacks from specified process names:

IdleWakeups -p audiodg.exe,dwm.exe trace.etl

Export idle wakeup callstacks and thread/process ids:

IdleWakeups --includeProcessAndThreadIds trace.etl

Show summary of idle wakeup statistics but don't export to pprof:

IdleWakeups --exportToPprof False --writeSummary trace.etl

Reduce time to load symbols by reading from symbol cache which already contains symbols:

IdleWakeups --loadFromSymCache trace.etl

Command line flags

-o, --outputFileName                (Default: profile.pb.gz) Output file name for gzipped pprof
                                    profile.

-p, --processFilter                 (Default: chrome.exe) Filter for process names
                                    (comma-separated) to be included in the analysis. All
                                    processes will be analyzed if set to *.

--includeInlinedFunctions           (Default: false) Whether inlined functions should be
                                    included in the exported profile (slow).

--stripSourceFileNamePrefix         (Default: ^c:/b/s/w/ir/cache/builder/) Prefix regex to
                                    strip out of source file names in the exported profile.

--timeStart                         Start of time range to analyze in seconds

--timeEnd                           End of time range to analyze in seconds

--includeProcessIds                 (Default: false) Includes process ids in the exported
                                    profile.

--includeProcessAndThreadIds        (Default: false)  Includes process and thread ids in the
                                    exported profile.

--includeWokenThreadIdsForWakers    (Default: false) Adds ids of woken threads for waker
                                    threads in the exported profile.

--splitChromeProcesses              (Default: true) Splits chrome.exe processes by type in the
                                    exported profile.

-s, --writeSummary                  (Default: false) Writes a summary after analysis has
                                    completed.
                                
--loadSymbols                       (Default: true) Whether symbols should be loaded.

--loadFromSymCache                  (Default: false) Loads symbols from cache where processed
                                    symbols are stored.

--exportToPprof                     (Default: true) Whether results shall be exported to a
                                    gzipped pprof profile.

--pprofComment                      (Default: ) Free-form annotation to add to the exported
                                    profile as comment.

--listProcesses                     (Default: false) Whether all process names (unique) shall
                                    be printed out instead of running an analysis.

-t, --tabbed                        (Default: false) Print results as a tab-separated grid.

-v, --verboseOutput                 (Default: false) Set output to verbose messages.

--help                              Display this help screen.

--version                           Display version information.

etlFileName (pos. 0)                Required. ETL trace file name.

Disclaimer:

This is not an officially supported Google product.