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Bug 1511201

Summary: UDS threads do not identify the VDO device they relate to
Product: Red Hat Enterprise Linux 7 Reporter: Bryan Gurney <bgurney>
Component: kmod-kvdoAssignee: Thomas Jaskiewicz <tjaskiew>
Status: CLOSED ERRATA QA Contact: Jakub Krysl <jkrysl>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 7.5CC: awalsh, limershe, tjaskiew
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: 6.1.0.42 Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2018-04-10 16:25:27 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:

Description Bryan Gurney 2017-11-08 21:57:15 UTC
Description of problem:
UDS is still creating threads using the thread names from user-mode albireo. So we have: callbackWorker, zoneIndexWorker (2 of these), volumeReader (2 of these), chapterWriter.

Version-Release number of selected component (if applicable):
kmod-kvdo-6.1.0.34-7.el7.x86_64

How reproducible:
100%

Steps to Reproduce:
1. Create a VDO volume.
2. Run "ps aux".
3. Look for threads named "callbackWorker", "chapterWriter", "volumeReader", or "zoneIndexWorker".

Actual results:
There are threads named threads named "callbackWorker", "chapterWriter", "volumeReader", or "zoneIndexWorker", with no indication of the associated VDO volume.

Expected results:
The UDS threads that are associated with a VDO volume have a label indicating their association.


Additional info:

Comment 2 Thomas Jaskiewicz 2017-11-09 22:37:11 UTC
Fixed in VDO 6.1.0.42

Threads that are common to all UDS indices have names starting with uds:.  "callbackWorker" becomes "uds:callbsckW".  The code has other such threads, but VDO will not use them.

Threads belonging to a VDO instance have names starting with kvdo0:.  The "0" is replaced by the same number so that the threads have the same kvdo<number>: prefix as the VDO threads for that VDO instance.  "chapterWriter" becomes "kvdo0:writer", "triageWorker" becomes "kvdo0:triageW", "volumeReader" becomes "kvdo0:reader", and "zoneIndexWorker" becomes "kvdo0:indexW".

Comment 4 Jakub Krysl 2017-11-14 13:54:36 UTC
Tested with kmod-kvdo-6.1.0.46-8, created 2 VDO volumes and compared ps aux. The only thread common to them is 'uds:callbsckW'. Other threads start with 'kvdo' and correct number of said vdo. When VDOs are removed, the only thread remaining is 'uds:callbsckW'.

Comment 7 errata-xmlrpc 2018-04-10 16:25:27 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/RHEA-2018:0900