Fix cpu hotplug atomic sleep issue #12714
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
behlendorf
approved these changes
Nov 2, 2021
ahrens
approved these changes
Nov 2, 2021
tonynguien
approved these changes
Nov 2, 2021
tonyhutter
pushed a commit
to tonyhutter/zfs
that referenced
this pull request
Mar 1, 2022
We move the spinlock unlock before the thread creation. This should be safe because the thread creation code doesn't actually manipulate any taskq data structures; that's done by the thread once it's created. We also remove the assertion that the maxthreads is the current threads plus one; that assertion could fail if multiple hotplug events come in quick succession, and the first new taskq thread hasn't had a chance to start processing yet. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Matthew Ahrens <mahrens@delphix.com> eviewed-by: Tony Nguyen <tony.nguyen@delphix.com> Signed-off-by: Paul Dagnelie <pcd@delphix.com> Closes openzfs#12714
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Motivation and Context
See #12696
Description
We move the spinlock unlock before the thread creation. This should be safe because the thread creation code doesn't actually manipulate any taskq data structures; that's done by the thread once it's created. We also remove the assertion that the maxthreads is the current threads plus one; that assertion could fail if multiple hotplug events come in in quick succession, and the first new taskq thread hasn't had a chance to start processing yet.
How Has This Been Tested?
Manually tested CPU hotplug to verify stability, normal ZFS test suite. The patch has also been tested by people in the original issue, and it seems to have removed the BUG message.
Types of changes
Checklist:
Signed-off-by.