Re: [PATCH 0/7] Structure and callback cleanups

[Nikolay Borisov <nborisov@suse.com>]

On 19.07.2018 14:05, David Sterba wrote:
> A handful of removed structure members that are not used,
> async_submit_bio is down by 16 bytes and async_cow by 8.
> 
> Some of the extent_io_ops callbacks are unnecessarily called indirectly.
> The rest of extent_io_ops is going to be transformed in following
> series.
> 
> David Sterba (7):
>   btrfs: remove unused member async_submit_bio::fs_info
>   btrfs: remove unused member async_submit_bio::bio_flags
>   btrfs: remove redundant member async_cow::root
>   btrfs: unify end_io callbacks of async_submit_bio
>   btrfs: drop extent_io_ops::tree_fs_info callback
>   btrfs: drop extent_io_ops::merge_bio_hook callback
>   btrfs: drop extent_io_ops::set_range_writeback callback
> 
>  fs/btrfs/compression.c | 10 +++-------
>  fs/btrfs/ctree.h       |  2 +-
>  fs/btrfs/disk-io.c     | 42 +++---------------------------------------
>  fs/btrfs/disk-io.h     |  5 +++--
>  fs/btrfs/extent_io.c   | 28 +++++++---------------------
>  fs/btrfs/extent_io.h   |  8 --------
>  fs/btrfs/inode.c       | 32 ++++++++------------------------
>  7 files changed, 25 insertions(+), 102 deletions(-)
> 

For the whole series (apart from my comments on 6/7):

Reviewed-by: Nikolay Borisov <nborisov@suse.com>

I'm guessing this will alleviate some of the performance hit stemming
from  spectre/meltdown mitigations.