When the scheduling policy is fixed share, GPU utilization is reported as higher than expected#

Description#

When the scheduling policy is fixed share, GPU engine utilization can be reported as higher than expected for a vGPU.

For example, GPU engine usage for six P40-4Q vGPUs on a Tesla P40 GPU might be reported as follows:

[root@localhost:~] nvidia-smi vgpu
Mon Aug 20 10:33:18 2018
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 390.42                 Driver Version: 390.42                    |
|-------------------------------+--------------------------------+------------+
| GPU  Name                     | Bus-Id                         | GPU-Util   |
|      vGPU ID    Name          | VM ID    VM Name               | vGPU-Util  |
|===============================+================================+============|
|   0  Tesla P40                | 00000000:81:00.0               |  99%       |
|      85109      GRID P40-4Q   | 85110    win7-xmpl-146048-1    |     32%    |
|      87195      GRID P40-4Q   | 87196    win7-xmpl-146048-2    |     39%    |
|      88095      GRID P40-4Q   | 88096    win7-xmpl-146048-3    |     26%    |
|      89170      GRID P40-4Q   | 89171    win7-xmpl-146048-4    |      0%    |
|      90475      GRID P40-4Q   | 90476    win7-xmpl-146048-5    |      0%    |
|      93363      GRID P40-4Q   | 93364    win7-xmpl-146048-6    |      0%    |
+-------------------------------+--------------------------------+------------+
|   1  Tesla P40                | 00000000:85:00.0               |   0%       |
+-------------------------------+--------------------------------+------------+

The vGPU utilization of vGPU 85109 is reported as 32%. For vGPU 87195, vGPU utilization is reported as 39%. And for 88095, it is reported as 26%. However, the expected vGPU utilization of any vGPU should not exceed approximately 16.7%.

This behavior is a result of the mechanism that is used to measure GPU engine utilization.

Status#

Open

Ref. ##

2227591