Yardstick Test Case Description TC012ΒΆ

Memory Bandwidth
test case id OPNFV_YARDSTICK_TC012_Memory Bandwidth
metric Megabyte per second (MBps)
test purpose Measure the rate at which data can be read from and written to the memory (this includes all levels of memory).
configuration

File: opnfv_yardstick_tc012.yaml

  • SLA (optional): 15000 (MBps) min_bw: The minimum amount of memory bandwidth that is accepted.
  • Size: 10 240 kB - test allocates twice that size (20 480kB) zeros it and then measures the time it takes to copy from one side to another.
  • Benchmark: rdwr - measures the time to read data into memory and then write data to the same location.
  • Warmup: 0 - the number of iterations to perform before taking actual measurements.
  • Iterations: 10 - test is run 10 times iteratively.
  • Interval: 1 - there is 1 second delay between each iteration.
test tool

Lmbench

Lmbench is a suite of operating system microbenchmarks. This test uses bw_mem tool from that suite. Lmbench is not always part of a Linux distribution, hence it needs to be installed in the test image.
references

man-pages

McVoy, Larry W., and Carl Staelin. “lmbench: Portable Tools for Performance Analysis.” USENIX annual technical conference. 1996.
applicability

Test can be configured with different:

  • memory sizes;
  • memory operations (such as rd, wr, rdwr, cp, frd, fwr, fcp, bzero, bcopy);
  • number of warmup iterations;
  • iterations and intervals.

There are default values for each above-mentioned option.
pre-test conditions

The test case image needs to be installed into Glance with Lmbench included in the image.

No POD specific requirements have been identified.
test sequence description and expected result
step 1

The host is installed as client. Lmbench’s bw_mem tool is invoked and logs are produced and stored.

Result: logs are stored.
test verdict Test fails if the measured memory bandwidth is below the SLA value or if there is a test case execution problem.