On Thu, Oct 14, 2021 at 3:13 AM Punit Agrawal <punitagrawal@xxxxxxxxx> wrote: > > Hi, > > Standard deviation is an important measure to evaluate the latency > response of a real time system. It is calculated by downstream tools > such as rteval but the value cannot be correctly calculated when the > latency value exceeds the range of histogram. > > This series adds support to report the streaming standard deviation of > latencies to cyclictest. This approach avoids having to track all > latency values and adds minimal overhead (two additional doubles and > compute steps) to each iteration. > > In terms of patch organization, the first 5 patches are clean-ups that > were noticed in the course of developing the support for standard > deviation. It should be possible to apply them indepndently. > > Patch 6 converts the existing average calculation to a streaming > version. This running average value is needed for the standard > deviation. > > Patch 7 finally adds support for calculating standard deviation. > > The changes were verified by capturing the latency samples and > verifying the average and standard deviation with manual calculation. > > All feedback welcome. > > Thanks, > Punit > > Punit Agrawal (7): > rt-tests: cyclictest: Drop unused defines > rt-tests: cyclictest: Simplify duplicate initialization of "stop" > rt-tests: cyclictest: Drop unnecessary variable "stopped" > rt-tests: cyclictest: Drop unnecessary variable "bufsize" > rt-tests: cyclictest: Move signal handler to avoid function > declaration > rt-tests: cyclictest: Use streaming algorithm to calculate averages > rt-tests: cyclictest: Add support to report standard deviation > > Makefile | 2 +- > src/cyclictest/cyclictest.c | 149 +++++++++++++++++++++--------------- > 2 files changed, 87 insertions(+), 64 deletions(-) > > -- > 2.32.0 > Hi Punit, Thanks for your contributions! I noticed there were no commit messages for patches 1 and 5. Would it be possible to add commit messages to all patches in the future? Commit messages help those trying to learn (Me :-) ) and understand the purpose of the patch. Thanks, Joe
