Developer Guide

  • 2021.2
  • 06/11/2021
  • Public
Contents

Command-Line Options

Running the MRL sample workload with the
-h
option yields the following usage message:
Usage: taskset --cpu-list 3 mrl_userspace_app --address ADDRESS --iterations ITERATIONS --processor {TGL-U,EHL} [--outliers OUTLIERS] [--threshold THRESHOLD]
Option
Description
taskset --cpu-list 3
Processor core on which the sample will run.
--address ADDRESS
Physical memory address of the PCIe device with
0x
prefix. Example: 0x607d4dc000.
--iterations ITERATIONS
Execute N iterations of the main loop to gather more precise timing statistics.
--processor PROCESSOR
Processor where the MRL application will be executed.
--outliers OUTLIERS
Optional. This parameter is used to filter iterations that executed greater than N instructions. By default, N is set to the expected amount of instructions for measuring latency of a single MMIO read transaction. By removing iterations with instructions greater than N, MRL is effectively masking interrupts and software overhead. (default: 90)
--threshold THRESHOLD
Optional. The MRL sample can hang due to a low outliers number. If
--outliers N
is too small, the sample will never count any iterations and will never stop running because it is waiting to collect N data points as specified in
--iterations
. To avoid the hang, use the threshold parameter to limit the number of iterations N that the sample should run. This parameter will stop the sample after it has run N iterations. (default: equal to 120% of
--iterations N
)
To get the physical memory address of the PCIe device, run the following commands on each board:
lspci | grep -E 'Ethernet controller: Intel Corporation'
The following output example shows the PCIe device name is aa:00.0.
aa:00.0 Ethernet controller: Intel Corporation Device 15f2 (rev 20)
If you see
15f2
in the output, the device is an Intel® Ethernet Controller I225. If you see
a0ac
or
4b32
in the output, the device is an integrated TSN Ethernet controller.
Run
lspci
with found PCIe device address and search for device memory.
lspci -s aa:00.0 -v | grep Memory
The following output example shows the addresses 88200000 and 88300000.
Memory at 88200000 (32-bit, non-prefetchable) [size=1M] Memory at 88300000 (32-bit, non-prefetchable) [size=16K]
Enter the address in the
--address
field with
0x
prefix.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.