Introduction to Omniperf¶

Slides
Recording in /appl/local/training/profiling-20230413/recordings/04_Intro_OmniPerf.mp4

Remarks¶

Warning

For security reasons it is best to run omniperf analyze on a single user machine that is protected by a firewall (which is why we do not want to install it visibly on LUMI). It opens an unprotected port to a webserver so everybody with access to LUMI can easily guess the port number and get access to some of your data that way.

Q&A¶

Not related to omniperf. On tranining/exercises/HPE/openacc-mpi-demos after doing sbatch job.slurm.
```
srun: error: CPU binding outside of job step allocation, allocated CPUs are: 0x01FFFFFFFFFFFFFE01FFFFFFFFFFFFFE.
srun: error: Task launch for StepId=3372350.2 failed on node nid007281: Unable to satisfy cpu bind request
srun: error: Application launch failed: Unable to satisfy cpu bind request
```
Answer
- let me fix it, I will report here when it is done (for the record, this is due to the today's change in Slurm)... done, please check.
  - what change in slurm happened today?
  - LUMI admins somehow reverted a change in Slurm that came in with the update where SLURM no longer propagates cpus-per-task if set in an SBATCH job comment into the srun. The old behaviour was restored but we tested the scripts yesterday. There was a user email this morning.
Slide 43, the kernels performance are good or not? There is a threshold in terms of distance from boundaries?

Answer

Will be in the recording. The performance is not very good (and take into account the scales are logarithmic so the dots are very far from the boundary).