Bug 1549698 - ceph tcmu-runner perf changes
Summary: ceph tcmu-runner perf changes
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Ceph Storage
Classification: Red Hat Storage
Component: iSCSI
Version: 3.0
Hardware: Unspecified
OS: Unspecified
low
medium
Target Milestone: z3
: 3.0
Assignee: Mike Christie
QA Contact: Tejas
Aron Gunn
URL:
Whiteboard:
: 1562390 1565570 (view as bug list)
Depends On:
Blocks: 1562459
TreeView+ depends on / blocked
 
Reported: 2018-02-27 16:46 UTC by Mike Christie
Modified: 2022-02-21 18:20 UTC (History)
8 users (show)

Fixed In Version: tcmu-runner-1.3.0-0.4.2.el7cp
Doc Type: Bug Fix
Doc Text:
.Tuning the kernel notifications for `tcmu-runner` Previously, `tcmu-runner` would wait to notify the kernel once all outstanding commands had completed. This caused higher latency for commands that were at the beginning of the queue. With this release, `tcmu-runner` will notify the kernel once the first command completes. Batching multiple commands completions together to notify the kernel will still occur, if multiple commands complete around the same time.
Clone Of:
Environment:
Last Closed: 2018-05-15 18:20:29 UTC
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Github open-iscsi tcmu-runner pull 392 0 None None None 2018-04-03 15:04:37 UTC
Red Hat Product Errata RHBA-2018:1563 0 None None None 2018-05-15 18:21:15 UTC

Description Mike Christie 2018-02-27 16:46:42 UTC 
Description of problem:

tcmu-runner tries to batch request completions, but this can result in lower IOPs and higher latency due to the first requests having to wait for the last ones to complete.

A modified version of this patch

[TODO for the patch is here https://github.com/open-iscsi/tcmu-runner/issues/359#issuecomment-360187930]:
https://github.com/open-iscsi/tcmu-runner/issues/359#issuecomment-359687757

will be merged upstream and needs to be brought into ceph's tcmu-runner repo.

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


How reproducible:


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Expected results:


Additional info:
Comment 3 Jason Dillaman 2018-03-30 13:53:11 UTC 
*** Bug 1562390 has been marked as a duplicate of this bug. ***
Comment 7 Ken Dreyer (Red Hat) 2018-05-03 17:29:40 UTC 
*** Bug 1565570 has been marked as a duplicate of this bug. ***
Comment 12 errata-xmlrpc 2018-05-15 18:20:29 UTC 
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2018:1563
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