Using KSRTM

Kernel System Response Time Measurement (KSRTM) is a Windows driver and utility that measures HAL-level timer latencies on the RTSS cores and provides reports and histograms of the results.

To measure HAL-level timer latency, run command prompt as Administrator and type the following:

"c:\program files\IntervalZero\rtx64\bin\ksrtm.exe" [/r|/k|/m][/h][/n][/s][/d][/l][/u minutes] seconds_to_sample

IMPORTANT! Do not attempt to stop the RTX64 subsystem while KSRTM is running. The subsystem may become unstable and crash.

Parameters

/r

Real-time HAL extension timer (default). Exercises the KSRTM test using the RTX64 hardware abstraction layer timer. Runs on as many cores as RTX64 is configured to use for real time.

/k

Kernel (DPC-level) timer. Exercises the KSRTM test using the Windows kernel timer. Only runs on one CPU.

/m

Multimedia (user-level) timer. Exercises the KSRTM test using the multimedia timer. Only runs on one CPU.

/h

Displays histogram of latencies (in addition to summary).

/n

Do not use real-time process and thread priorities. Avoids setting highest real-time priority (relevant only for the multimedia user level timer).

/s

Sound output (square wave driven by timer). Only practical when RTX64 is configured to use one real time core. With two or more cores driving the speaker, there are collisions leading to “dirty” sound.

/d

Display loaded driver information. Causes the program to display information about currently loaded drivers, such as the name, start address, and end address.

/l

Longest latency event information. Only supported for the RTX64 HAL timer test [/r].

/u minutes

Minutes between display updates. For tests that are set to last longer than a minute (seconds_to_sample>60), this option forces the program to display the current data after the specified number of minutes.

seconds_to_sample

Duration in seconds to sample timer response latencies.