[PATCH RFC 0/7] Use Maple Trees for simple_offset utilities

[Chuck Lever <cel@kernel.org>]

In an effort to address slab fragmentation issues reported a few
months ago, I've replaced the use of xarrays for the directory
offset map in "simple" file systems (including tmpfs).

This patch set passes functional testing and is ready for code
review. But I don't have the facilities to re-run the performance
tests that identified the regression. We expect the performance of
this implementation will need additional improvement.

Thanks to Liam Howlett for helping me get this working.

---

Chuck Lever (6):
      libfs: Rename "so_ctx"
      libfs: Define a minimum directory offset
      libfs: Add simple_offset_empty()
      maple_tree: Add mtree_alloc_cyclic()
      libfs: Convert simple directory offsets to use a Maple Tree
      libfs: Re-arrange locking in offset_iterate_dir()

Liam R. Howlett (1):
      test_maple_tree: testing the cyclic allocation


 fs/libfs.c                 | 125 +++++++++++++++++++++++--------------
 include/linux/fs.h         |   6 +-
 include/linux/maple_tree.h |   7 +++
 lib/maple_tree.c           |  93 +++++++++++++++++++++++++++
 lib/test_maple_tree.c      |  44 +++++++++++++
 mm/shmem.c                 |   4 +-
 6 files changed, 227 insertions(+), 52 deletions(-)

--
Chuck Lever