Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Use more atomics in refcounts. #12420

Merged
merged 1 commit into from
Aug 17, 2021
Merged

Use more atomics in refcounts. #12420

merged 1 commit into from
Aug 17, 2021

Conversation

amotin
Copy link
Member

@amotin amotin commented Jul 22, 2021

Use atomic_load_64() for zfs_refcount_count() to prevent torn reads
on 32-bit platforms. On 64-bit ones it should not change anything.

When built with ZFS_DEBUG but running without tracking enabled use
atomics instead of mutexes same as for builds without ZFS_DEBUG.
Since rc_tracked can't change live we can check it without lock.

Types of changes

  • Bug fix (non-breaking change which fixes an issue)
  • New feature (non-breaking change which adds functionality)
  • Performance enhancement (non-breaking change which improves efficiency)
  • Code cleanup (non-breaking change which makes code smaller or more readable)
  • Breaking change (fix or feature that would cause existing functionality to change)
  • Library ABI change (libzfs, libzfs_core, libnvpair, libuutil and libzfsbootenv)
  • Documentation (a change to man pages or other documentation)

Checklist:

@amotin amotin requested a review from behlendorf July 22, 2021 21:57
@amotin amotin added the Status: Code Review Needed Ready for review and testing label Jul 22, 2021
behlendorf
behlendorf approved these changes Jul 23, 2021
View reviewed changes
module/zfs/refcount.c Show resolved Hide resolved
@amotin
Use more atomics in refcounts.
d85cdf2 
Use atomic_load_64() for zfs_refcount_count() to prevent torn reads
on 32-bit platforms.  On 64-bit ones it should not change anything.

When built with ZFS_DEBUG but running without tracking enabled use
atomics instead of mutexes same as for builds without ZFS_DEBUG.
Since rc_tracked can't change live we can check it without lock.

Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
@behlendorf behlendorf added Status: Accepted Ready to integrate (reviewed, tested) and removed Status: Code Review Needed Ready for review and testing labels Jul 29, 2021
@mmaybee mmaybee merged commit e829a86 into openzfs:master Aug 17, 2021
@amotin amotin deleted the refcount branch August 24, 2021 20:17
behlendorf pushed a commit to behlendorf/zfs that referenced this pull request Aug 24, 2021
@amotin @behlendorf
Use more atomics in refcounts
10d7bfb 
Use atomic_load_64() for zfs_refcount_count() to prevent torn reads
on 32-bit platforms.  On 64-bit ones it should not change anything.

When built with ZFS_DEBUG but running without tracking enabled use
atomics instead of mutexes same as for builds without ZFS_DEBUG.
Since rc_tracked can't change live we can check it without lock.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes openzfs#12420
behlendorf pushed a commit that referenced this pull request Aug 31, 2021
@amotin @behlendorf
Use more atomics in refcounts
72175a5 
Use atomic_load_64() for zfs_refcount_count() to prevent torn reads
on 32-bit platforms.  On 64-bit ones it should not change anything.

When built with ZFS_DEBUG but running without tracking enabled use
atomics instead of mutexes same as for builds without ZFS_DEBUG.
Since rc_tracked can't change live we can check it without lock.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes #12420
tonyhutter pushed a commit to tonyhutter/zfs that referenced this pull request Sep 15, 2021
@amotin @tonyhutter
Use more atomics in refcounts
5afc35b 
Use atomic_load_64() for zfs_refcount_count() to prevent torn reads
on 32-bit platforms.  On 64-bit ones it should not change anything.

When built with ZFS_DEBUG but running without tracking enabled use
atomics instead of mutexes same as for builds without ZFS_DEBUG.
Since rc_tracked can't change live we can check it without lock.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes openzfs#12420
rincebrain pushed a commit to rincebrain/zfs that referenced this pull request Sep 22, 2021
@amotin @rincebrain
Use more atomics in refcounts
77e3e9f 
Use atomic_load_64() for zfs_refcount_count() to prevent torn reads
on 32-bit platforms.  On 64-bit ones it should not change anything.

When built with ZFS_DEBUG but running without tracking enabled use
atomics instead of mutexes same as for builds without ZFS_DEBUG.
Since rc_tracked can't change live we can check it without lock.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes openzfs#12420
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Reviewers

@behlendorf behlendorf behlendorf approved these changes

@ahrens ahrens ahrens approved these changes

Assignees

@mmaybee mmaybee

Labels
Status: Accepted Ready to integrate (reviewed, tested)
Projects
None yet
Milestone
No milestone
Development

Successfully merging this pull request may close these issues.
4 participants
@amotin @behlendorf @ahrens @mmaybee