DAX PMDs have been disabled since Jan Kara introduced DAX radix tree based locking. This series allows DAX PMDs to participate in the DAX radix tree based locking scheme so that they can be re-enabled.
Previously we had talked about this series going through the XFS tree, but Jan has a patch set that will need to build on this series and it heavily modifies the MM code. I think he would prefer that series to go through Andrew Morton's -MM tree, so it probably makes sense for this series to go through that same tree. For reference, here is the series from Jan that I was talking about: https://marc.info/?l=linux-mm&m=147499252322902&w=2 Andrew, can you please pick this up for the v4.10 merge window? This series is currently based on v4.9-rc3. I tried to rebase onto a -mm branch or tag, but couldn't find one that contained the DAX iomap changes that were merged as part of the v4.9 merge window. I'm happy to rebase & test on a v4.9-rc* based -MM branch or tag whenever they are available. Changes since v8: - Rebased onto v4.9-rc3. - Updated the DAX PMD fault path so that on fallback we always check to see if we are dealing with a transparent huge page, and if we are we will split it. This was already happening for one of the fallback cases via a patch from Toshi, and Jan hit a deadlock in another fallback case where the same splitting was needed. (Jan & Toshi) This series has passed all my xfstests testing, including the test that was hitting the deadlock with v8. Here is a tree containing my changes: https://git.kernel.org/cgit/linux/kernel/git/zwisler/linux.git/log/?h=dax_pmd_v9 Ross Zwisler (16): ext4: tell DAX the size of allocation holes dax: remove buffer_size_valid() ext2: remove support for DAX PMD faults dax: make 'wait_table' global variable static dax: remove the last BUG_ON() from fs/dax.c dax: consistent variable naming for DAX entries dax: coordinate locking for offsets in PMD range dax: remove dax_pmd_fault() dax: correct dax iomap code namespace dax: add dax_iomap_sector() helper function dax: dax_iomap_fault() needs to call iomap_end() dax: move RADIX_DAX_* defines to dax.h dax: move put_(un)locked_mapping_entry() in dax.c dax: add struct iomap based DAX PMD support xfs: use struct iomap based DAX PMD fault path dax: remove "depends on BROKEN" from FS_DAX_PMD fs/Kconfig | 1 - fs/dax.c | 826 +++++++++++++++++++++++++++++----------------------- fs/ext2/file.c | 35 +-- fs/ext4/inode.c | 3 + fs/xfs/xfs_aops.c | 26 +- fs/xfs/xfs_aops.h | 3 - fs/xfs/xfs_file.c | 10 +- include/linux/dax.h | 58 +++- mm/filemap.c | 5 +- 9 files changed, 537 insertions(+), 430 deletions(-) -- 2.7.4