Bug 2184914 - DPDK-friendly VMs should request isolated emulator thread
Summary: DPDK-friendly VMs should request isolated emulator thread
Keywords:
Status: CLOSED WONTFIX
Alias: None
Product: Container Native Virtualization (CNV)
Classification: Red Hat
Component: Networking
Version: 4.13.0
Hardware: Unspecified
OS: Unspecified
medium
medium
Target Milestone: ---
: 4.13.2
Assignee: Petr Horáček
QA Contact: Yossi Segev
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2023-04-06 07:41 UTC by Petr Horáček
Modified: 2023-06-14 13:04 UTC (History)
0 users

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Last Closed: 2023-06-14 13:04:47 UTC
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System ID Private Priority Status Summary Last Updated
Red Hat Issue Tracker CNV-27911 0 None None None 2023-04-06 07:45:30 UTC

Description Petr Horáček 2023-04-06 07:41:58 UTC
Description of problem:
Currently, our DPDK checkup VM as well as our reference DPDK-VM spec does not prescribe setting spec.domain.cpu.isolateEmulatorThread=true.

Running simple testpmd tests with no disk I/O you will not catch emulator threads or IOthreads isolation issues. However, real applications typically have a couple of threads that do regular I/O (e.g. writing logs to disk).

We should enable this attribute.

Version-Release number of selected component (if applicable):
4.13 rc

How reproducible:
Was not reproduced

Steps to Reproduce:
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Actual results:


Expected results:


Additional info:

Comment 1 Petr Horáček 2023-05-11 10:09:56 UTC
Deferring to 4.13.2 to save capacity verifying urgent 4.13.1 bugs.

Comment 2 Petr Horáček 2023-06-14 13:04:47 UTC
Copying comment from the linked Jira https://issues.redhat.com/browse/CNV-27911:

  > Isolation of the emulator thread should not affect zero packet loss (IOW DPDK performance), therefore can't see why this is necessary.
  >
  > It should be up to the user to enable this feature (or not), but DPDK zero packet loss should work whether isolation of emulator thread is enabled or disabled.


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