How to set xperf so it writes more often to the log file?

To make xperf write more frequently to the log file, you can adjust the buffer size and buffer count settings. Xperf is part of the Windows Performance Toolkit (WPT) and is used for performance analysis and tracing.

By default, xperf uses a circular buffer to store the recorded events. The buffer size and buffer count determine how much data is stored and how often it is flushed to the log file. You can increase the buffer size and buffer count to make xperf write more frequently to the log file.

Here's how you can set the buffer size and buffer count in xperf:

1. Open a Command Prompt with administrative privileges.

2. Use the xperf -on command to start the tracing session. For example:

   bashCopy code
   xperf -on PROC_THREAD+LOADER+CSWITCH+FILENAME -BufferSize 1024 -MinBuffers 256 -MaxBuffers 256 -MaxFile 1024
   
   

   In this example:

   • -BufferSize 1024: Specifies the buffer size (in kilobytes).
   • -MinBuffers 256: Specifies the minimum number of buffers.
   • -MaxBuffers 256: Specifies the maximum number of buffers.
   • -MaxFile 1024: Specifies the maximum size of the log file (in megabytes). The file will roll over to a new file if it reaches this size.

3. Perform the tasks you want to capture performance data for.

4. Use the xperf -d command to stop the tracing and save the data to a file:

   bashCopy code
   xperf -d output.etl
   
   

   Replace output.etl with the desired filename for the log file.

By increasing the buffer size and buffer count, xperf will write more often to the log file, capturing a higher frequency of performance data. Keep in mind that larger buffer sizes and buffer counts may require more memory and disk space, so adjust the settings based on your specific needs and system resources.