[PATCH v4 0/5] vfs: Use dlock list for SB's s_inodes list

From: Waiman Long
Date: Fri Jul 22 2016 - 16:36:30 EST

- As suggested by Al, encapsulate the dlock list mechanism into
the dlist_for_each_entry() and dlist_for_each_entry_safe()
which are the equivalent of list_for_each_entry() and
list_for_each_entry_safe() for regular linked list. That simplifies
the changes in the call sites that perform dlock list iterations.
- Add a new patch to make the percpu head structure cacheline aligned
to prevent cacheline contention from disrupting the performance
of nearby percpu variables.

- Remove the 2 persubnode API patches.
- Merge __percpu tag patch 2 into patch 1.
- As suggested by Tejun Heo, restructure the dlock_list_head data
structure to hide the __percpu tag and rename some of the functions
and structures.
- Move most of the code from dlock_list.h to dlock_list.c and export
the symbols.

- Add a set of simple per-subnode APIs that is between percpu and
per-node in granularity.
- Make dlock list to use the per-subnode APIs so as to reduce the
total number of separate linked list that needs to be managed
and iterated.
- There is no change in patches 1-5.

This is a follow up of the following patchset:

[PATCH v7 0/4] vfs: Use per-cpu list for SB's s_inodes list

The main change is the renaming of percpu list to dlock list, as
suggested by Christoph Lameter. It also adds a new patch from Boqun
Feng to add the __percpu modifier for parameters.

Patch 1 introduces the dlock list.

Patch 2 cleans up the fsnotify_unmount_inodes() function by making
the code simpler and more standard.

Patch 3 replaces the use of list_for_each_entry_safe() in
evict_inodes() and invalidate_inodes() by list_for_each_entry().

Patch 4 modifies the superblock and inode structures to use the dlock
list. The corresponding functions that reference those structures
are modified.

Patch 5 changes the percpu head structures allocation to make them
cacheline-aligned to avoid hurting performance of other nearby percpu

Jan Kara (2):
fsnotify: Simplify inode iteration on umount
vfs: Remove unnecessary list_for_each_entry_safe() variants

Waiman Long (3):
lib/dlock-list: Distributed and lock-protected lists
vfs: Use dlock list for superblock's inode list
lib/dlock-list: Allow cacheline alignment of percpu head

fs/block_dev.c | 9 +-
fs/drop_caches.c | 9 +-
fs/fs-writeback.c | 9 +-
fs/inode.c | 38 +++----
fs/notify/inode_mark.c | 52 ++-------
fs/quota/dquot.c | 14 +--
fs/super.c | 7 +-
include/linux/dlock-list.h | 242 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/fs.h | 8 +-
lib/Makefile | 2 +-
lib/dlock-list.c | 198 ++++++++++++++++++++++++++++++++++++
11 files changed, 494 insertions(+), 94 deletions(-)
create mode 100644 include/linux/dlock-list.h
create mode 100644 lib/dlock-list.c