[PATCH 0/6] btrfs: allocator perf improvements

[Boris Burkov <boris@bur.io>]

Working on the bugs to do with large fs-es and unused block groups

https://lore.kernel.org/linux-btrfs/20260916230447.GA1706558@zen.localdomain/T/#t
and
https://lore.kernel.org/linux-btrfs/cover.1790641111.git.boris@bur.io/T/#t

revealed some low hanging fruit in allocation performance for very large
mostly full fs-es. The gist is to try to skip unnecessary operations per block
group which adds up with 10s of thousands of obviously skippable block
groups. Running 20k fallocates in a loop on a sparse file fs improved from
~40s to ~7s.

Boris Burkov (6):
  btrfs: skip unhelpful size class relaxing allocation loops
  btrfs: don't take block group references in find_free_extent()
  btrfs: remove redundant checks in find_free_extent() hint path
  btrfs: factor the find_free_extent() block group skip into a helper
  btrfs: find_free_extent checks full block groups unlocked
  btrfs: find_free_extent checks size class unlocked

 fs/btrfs/extent-tree.c | 88 +++++++++++++++++++++++++++++-------------
 fs/btrfs/extent-tree.h |  3 ++
 2 files changed, 65 insertions(+), 26 deletions(-)

-- 
2.55.0