[PATCH v5 00/78] XArray v5

From: Matthew Wilcox
Date: Fri Dec 15 2017 - 17:25:22 EST


From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>

Again, this patch set does not apply to any particular tree
because it depends on things which are purely noise, and I'm trying
to keep the patch count down [1]. If you want it in a git tree, try
http://git.infradead.org/users/willy/linux-dax.git/shortlog/refs/heads/xarray-2017-12-11
(note change of date from last posting)

I've been getting progressively fewer bug reports from 0day. I might
almost consider booting this on one of my test machines soon. The only
bug report I don't believe I've addressed yet is a compile failure
on ia64. I've resurrected my old McKinley and I'm building gcc 6.4 on
it to see if I can reproduce it (Debian only has 4.8 for ia64).

I'd really like an ACK from Darrick on patch 1 (and then I'll stop
posting it). I'd like ACKs from the other maintainers whose radix
trees I'm converting:

mm-cgroup-writeback
vmalloc
brd
xfs (again, Dave's feedback has been invaluable)
xhci-mem
raid5-cache
irqdomain
fscache

I don't imagine anybody has the stomach to review the entire pagecache
conversion, but you don't have to do all 44 patches at once. Please don't
make me beg for reviewers in Park City.

[1] 78 patches. Haha. I can squash a bunch of them together for
posting in future if you like, but the diffstat is still intense:
162 files changed, 6305 insertions(+), 4595 deletions(-).

In case the +/- worries you, each user of the xarray has, so far, lost
lines of code, and deleting the radix tree code once all the users are
converted will net us back 2270 lines. And there's way more documentation
of the XArray than there was of the radix tree.

Bug fixes:
- Fixed bisectability bug (thanks, 0day!)
- Fixed builds with !CONFIG_RADIX_TREE_MULTIORDER
- Fixed shmem_add_to_page_cache() and add_to_swap_cache(). Just a typo.
- Changed xa_ functions which return an error to use xa_err instead of ERR_PTR.
- Fixed a bug which could cause xas_for_each_tag() to terminate early.
- Removed spurious VM_BUG_ON_PAGE in page_cache_delete_batch
- Clear tags before erasing an entry

Cleanup:
- Renamed node->root to ->array.
- Renamed node->exceptional to ->nr_values.
- Improved debug output.
- Removed xa_lock_held. The few users opencode lockdep_is_held().
- Made xas_error use unlikely(). Errors are always unlikely.
- Changed xas errors to be the same as xa errors.
- Changed xa_set_tag(), xa_clear_tag(), __xa_set_tag() and __xa_get_tag() to
return void. The functionality is not being used.
- Rewrote xa_to_node() to be more efficient.
- Replaced license text with SPDX tags
- Pulled some boilerplate out of __xa_erase, xa_store and xa_cmpxchg into
the new xas_result()
- Applied several of Randy's suggestions to the documentation. Also lots
of tweaking.

New features:
- Added xa_count()
- Added xa_store_empty() as a convenience function.
- Changed xarray to not use irqsafe locks by default. The IDR continues to
use irqsafe locks for now.
- Added __xa_store and __xa_cmpxchg variations so users can do their own
locking.
- Exposed & documented the xa_lock member of struct xarray.
- Converted fscache to XArray
- Converted irqdomain to XArray
- Converted raid5-cache to XArray


Matthew Wilcox (78):
xfs: Rename xa_ elements to ail_
fscache: Use appropriate radix tree accessors
xarray: Add the xa_lock to the radix_tree_root
page cache: Use xa_lock
xarray: Replace exceptional entries
xarray: Change definition of sibling entries
xarray: Add definition of struct xarray
xarray: Define struct xa_node
xarray: Add documentation
xarray: Add xa_load
xarray: Add xa_get_tag, xa_set_tag and xa_clear_tag
xarray: Add xa_store
xarray: Add xa_cmpxchg
xarray: Add xa_for_each
xarray: Add xas_for_each_tag
xarray: Add xa_get_entries, xa_get_tagged and xa_get_maybe_tag
xarray: Add xa_destroy
xarray: Add xas_next and xas_prev
xarray: Add xas_create_range
xarray: Add MAINTAINERS entry
xarray: Add ability to store errno values
idr: Convert to XArray
ida: Convert to XArray
page cache: Convert hole search to XArray
page cache: Add page_cache_range_empty function
page cache: Add and replace pages using the XArray
page cache: Convert page deletion to XArray
page cache: Convert page cache lookups to XArray
page cache: Convert delete_batch to XArray
page cache: Remove stray radix comment
mm: Convert page-writeback to XArray
mm: Convert workingset to XArray
mm: Convert truncate to XArray
mm: Convert add_to_swap_cache to XArray
mm: Convert delete_from_swap_cache to XArray
mm: Convert __do_page_cache_readahead to XArray
mm: Convert page migration to XArray
mm: Convert huge_memory to XArray
mm: Convert collapse_shmem to XArray
mm: Convert khugepaged_scan_shmem to XArray
pagevec: Use xa_tag_t
shmem: Convert replace to XArray
shmem: Convert shmem_confirm_swap to XArray
shmem: Convert find_swap_entry to XArray
shmem: Convert shmem_tag_pins to XArray
shmem: Convert shmem_wait_for_pins to XArray
shmem: Convert shmem_add_to_page_cache to XArray
shmem: Convert shmem_alloc_hugepage to XArray
shmem: Convert shmem_free_swap to XArray
shmem: Convert shmem_partial_swap_usage to XArray
shmem: Comment fixups
btrfs: Convert page cache to XArray
fs: Convert buffer to XArray
fs: Convert writeback to XArray
nilfs2: Convert to XArray
f2fs: Convert to XArray
lustre: Convert to XArray
dax: Convert dax_unlock_mapping_entry to XArray
dax: Convert lock_slot to XArray
dax: More XArray conversion
dax: Convert __dax_invalidate_mapping_entry to XArray
dax: Convert dax_writeback_one to XArray
dax: Convert dax_insert_pfn_mkwrite to XArray
dax: Convert dax_insert_mapping_entry to XArray
dax: Convert grab_mapping_entry to XArray
dax: Fix sparse warning
page cache: Finish XArray conversion
mm: Convert cgroup writeback to XArray
vmalloc: Convert to XArray
brd: Convert to XArray
xfs: Convert m_perag_tree to XArray
xfs: Convert pag_ici_root to XArray
xfs: Convert xfs dquot to XArray
xfs: Convert mru cache to XArray
usb: Convert xhci-mem to XArray
md: Convert raid5-cache to XArray
irqdomain: Convert to XArray
fscache: Convert to XArray

Documentation/cgroup-v1/memory.txt | 2 +-
Documentation/core-api/index.rst | 1 +
Documentation/core-api/xarray.rst | 347 +++++
Documentation/vm/page_migration | 14 +-
MAINTAINERS | 12 +
arch/arm/include/asm/cacheflush.h | 6 +-
arch/nios2/include/asm/cacheflush.h | 6 +-
arch/parisc/include/asm/cacheflush.h | 6 +-
arch/powerpc/include/asm/book3s/64/pgtable.h | 4 +-
arch/powerpc/include/asm/nohash/64/pgtable.h | 4 +-
drivers/block/brd.c | 93 +-
drivers/gpu/drm/i915/i915_gem.c | 17 +-
drivers/md/raid5-cache.c | 119 +-
drivers/staging/lustre/lustre/llite/glimpse.c | 12 +-
drivers/staging/lustre/lustre/mdc/mdc_request.c | 16 +-
drivers/usb/host/xhci-mem.c | 68 +-
drivers/usb/host/xhci.h | 6 +-
fs/afs/write.c | 9 +-
fs/btrfs/btrfs_inode.h | 7 +-
fs/btrfs/compression.c | 6 +-
fs/btrfs/extent_io.c | 24 +-
fs/btrfs/inode.c | 70 -
fs/buffer.c | 25 +-
fs/cifs/file.c | 9 +-
fs/dax.c | 384 +++---
fs/ext4/inode.c | 2 +-
fs/f2fs/data.c | 9 +-
fs/f2fs/dir.c | 5 +-
fs/f2fs/gc.c | 2 +-
fs/f2fs/inline.c | 6 +-
fs/f2fs/node.c | 10 +-
fs/fs-writeback.c | 37 +-
fs/fscache/cookie.c | 6 +-
fs/fscache/internal.h | 2 +-
fs/fscache/object.c | 2 +-
fs/fscache/page.c | 152 +--
fs/fscache/stats.c | 6 +-
fs/gfs2/aops.c | 2 +-
fs/inode.c | 11 +-
fs/nfs/blocklayout/blocklayout.c | 2 +-
fs/nilfs2/btnode.c | 41 +-
fs/nilfs2/page.c | 78 +-
fs/proc/task_mmu.c | 2 +-
fs/xfs/libxfs/xfs_sb.c | 11 +-
fs/xfs/libxfs/xfs_sb.h | 2 +-
fs/xfs/xfs_buf_item.c | 10 +-
fs/xfs/xfs_dquot.c | 42 +-
fs/xfs/xfs_dquot_item.c | 11 +-
fs/xfs/xfs_icache.c | 146 +-
fs/xfs/xfs_icache.h | 10 +-
fs/xfs/xfs_inode.c | 24 +-
fs/xfs/xfs_inode_item.c | 22 +-
fs/xfs/xfs_log.c | 6 +-
fs/xfs/xfs_log_recover.c | 80 +-
fs/xfs/xfs_mount.c | 22 +-
fs/xfs/xfs_mount.h | 6 +-
fs/xfs/xfs_mru_cache.c | 72 +-
fs/xfs/xfs_qm.c | 32 +-
fs/xfs/xfs_qm.h | 18 +-
fs/xfs/xfs_trans.c | 18 +-
fs/xfs/xfs_trans_ail.c | 152 +--
fs/xfs/xfs_trans_buf.c | 4 +-
fs/xfs/xfs_trans_priv.h | 42 +-
include/linux/backing-dev-defs.h | 2 +-
include/linux/backing-dev.h | 14 +-
include/linux/fs.h | 68 +-
include/linux/fscache.h | 8 +-
include/linux/idr.h | 166 ++-
include/linux/irqdomain.h | 10 +-
include/linux/mm.h | 2 +-
include/linux/pagemap.h | 16 +-
include/linux/pagevec.h | 8 +-
include/linux/radix-tree.h | 95 +-
include/linux/swap.h | 5 +-
include/linux/swapops.h | 19 +-
include/linux/xarray.h | 1026 ++++++++++++++
kernel/irq/irqdomain.c | 39 +-
kernel/pid.c | 2 +-
lib/Makefile | 2 +-
lib/idr.c | 633 +++++----
lib/radix-tree.c | 451 ++-----
lib/xarray.c | 1646 +++++++++++++++++++++++
mm/backing-dev.c | 23 +-
mm/filemap.c | 748 ++++------
mm/huge_memory.c | 23 +-
mm/khugepaged.c | 182 +--
mm/madvise.c | 2 +-
mm/memcontrol.c | 6 +-
mm/migrate.c | 41 +-
mm/mincore.c | 2 +-
mm/page-writeback.c | 78 +-
mm/readahead.c | 10 +-
mm/rmap.c | 4 +-
mm/shmem.c | 311 ++---
mm/swap.c | 6 +-
mm/swap_state.c | 124 +-
mm/truncate.c | 45 +-
mm/vmalloc.c | 39 +-
mm/vmscan.c | 14 +-
mm/workingset.c | 87 +-
tools/include/linux/spinlock.h | 10 +-
tools/testing/radix-tree/.gitignore | 2 +
tools/testing/radix-tree/Makefile | 15 +-
tools/testing/radix-tree/idr-test.c | 29 +-
tools/testing/radix-tree/linux/bug.h | 1 +
tools/testing/radix-tree/linux/kconfig.h | 1 +
tools/testing/radix-tree/linux/kernel.h | 4 +
tools/testing/radix-tree/linux/rcupdate.h | 2 +
tools/testing/radix-tree/linux/xarray.h | 3 +
tools/testing/radix-tree/multiorder.c | 83 +-
tools/testing/radix-tree/regression1.c | 68 +-
tools/testing/radix-tree/test.c | 8 +-
tools/testing/radix-tree/xarray-test.c | 512 +++++++
113 files changed, 5889 insertions(+), 3178 deletions(-)
create mode 100644 Documentation/core-api/xarray.rst
create mode 100644 include/linux/xarray.h
create mode 100644 lib/xarray.c
create mode 100644 tools/testing/radix-tree/linux/kconfig.h
create mode 100644 tools/testing/radix-tree/linux/xarray.h
create mode 100644 tools/testing/radix-tree/xarray-test.c

--
2.15.1