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[0/4] Replace custom device-replace locking with rwsem

Message ID cover.1542717531.git.dsterba@suse.com (mailing list archive)
Headers show
Series Replace custom device-replace locking with rwsem | expand

Message

David Sterba Nov. 20, 2018, 12:50 p.m. UTC 
The first cleanup part went to 4.19, the actual switch from the custom
locking to rswem was postponed as I found performance degradation. This
turned out to be related to VM cache settings, so I'm resending the
series again.

The custom locking is based on rwlock protected reader/writer counters,
waitqueues, which essentially is what the readwrite semaphore does.

Previous patchset:
https://lore.kernel.org/linux-btrfs/cover.1536331604.git.dsterba@suse.com/

Patches correspond to 8/11-11/11 and there's no change besides
refreshing on top of current misc-next.

David Sterba (4):
  btrfs: reada: reorder dev-replace locks before radix tree preload
  btrfs: dev-replace: swich locking to rw semaphore
  btrfs: dev-replace: remove custom read/write blocking scheme
  btrfs: dev-replace: open code trivial locking helpers

 fs/btrfs/ctree.h       |  4 +-
 fs/btrfs/dev-replace.c | 97 ++++++++++++++----------------------------
 fs/btrfs/dev-replace.h |  5 ---
 fs/btrfs/disk-io.c     |  4 +-
 fs/btrfs/reada.c       | 16 ++++---
 fs/btrfs/scrub.c       | 15 ++++---
 fs/btrfs/volumes.c     | 27 ++++++------
 7 files changed, 63 insertions(+), 105 deletions(-)

Comments

David Sterba Dec. 3, 2018, 5:14 p.m. UTC | #1 
On Tue, Nov 20, 2018 at 01:50:54PM +0100, David Sterba wrote:
> The first cleanup part went to 4.19, the actual switch from the custom
> locking to rswem was postponed as I found performance degradation. This
> turned out to be related to VM cache settings, so I'm resending the
> series again.
> 
> The custom locking is based on rwlock protected reader/writer counters,
> waitqueues, which essentially is what the readwrite semaphore does.
> 
> Previous patchset:
> https://lore.kernel.org/linux-btrfs/cover.1536331604.git.dsterba@suse.com/
> 
> Patches correspond to 8/11-11/11 and there's no change besides
> refreshing on top of current misc-next.
> 
> David Sterba (4):
>   btrfs: reada: reorder dev-replace locks before radix tree preload
>   btrfs: dev-replace: swich locking to rw semaphore
>   btrfs: dev-replace: remove custom read/write blocking scheme
>   btrfs: dev-replace: open code trivial locking helpers

This has been sitting in for-next for some time, no problems reported.
If anybody wants to add a review tag, please let me know. I'm going to
add the patchset to misc-next soon.