[elrepo] Performance issue

[Mahmood Naderan]

Hi,
I am using a Centos 7 where the default kernel version is 3.10. I have
installed that on a VirtualBox as a test system. Then I decided to upgrade
the kernel to 4.15 with the elrepo packages.

With the NAS parallel benchmark suite, I have noticed some performance
degradation. The runtime is about one minute longer with 4.15. I know that
this using VirtualBox is not a good infrastructure for performance
measurements, but may be can be used as a hint.

See the results below

Kernel-3.10
  bt.C.4    =>    698.12 sec
  ep.D.4    =>    2561.44 sec
  cg.C.2    =>    187.96 sec
  ft.C.2    =>    288.49 sec
  ft.C.4    =>    160.72 sec
  lu.C.4    =>    541.46 sec
  lu.D.4    =>    12705.02 sec

Kernel-4.15
  bt.C.4    =>    746.17 sec
  ep.D.4    =>    2510.52 sec
  cg.C.2    =>    209.17 sec
  ft.C.2    =>    284.43 sec
  ft.C.4    =>    155.67 sec
  lu.C.4    =>    646.67 sec
  lu.D.4    =>    16930.73 sec

Any idea?

Regards,
Mahmood
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.elrepo.org/pipermail/elrepo/attachments/20180211/7d023a4b/attachment.html>