RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.

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:

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".

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'.

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