v8->v9: - The last 2 patches in v8 were dropped because there is no more user that can use them. - Include Davidlohr's dlock_lists_empty() scaling patch. - Rebase the code to 4.19-rc3. v8 patch: https://lkml.org/lkml/2017/10/31/776 This patchset has been dormant for almost a year. Now I am going to restart it again. This patchset provides new APIs for a set of distributed locked lists (one/CPU core) to minimize lock and cacheline contention. Insertion and deletion to the list will be cheap and relatively contention free. Lookup, on the other hand, may be a bit more costly as there are multiple lists to iterate. This is not really a problem for the replacement of superblock's inode list by dlock list included in the patchset as lookup isn't needed. Patch 1 introduces the dlock list. The list heads are allocated by kcalloc() instead of percpu_alloc(). Each list head entry is cacheline aligned to minimize contention. Patch 2 replaces the use of list_for_each_entry_safe() in evict_inodes() and invalidate_inodes() by list_for_each_entry(). Patch 3 modifies the superblock and inode structures to use the dlock list. The corresponding functions that reference those structures are modified. Patch 4 makes the sibling CPUs use the same dlock list head to reduce the number of list heads that need to be iterated. Patch 5 improves the performance of dlock_lists_empty() call. See patch 3 for some performance data for this patchset. Davidlohr Bueso (1): lib/dlock-list: Scale dlock_lists_empty() Jan Kara (1): 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: Make sibling CPUs share the same linked list fs/block_dev.c | 9 +- fs/drop_caches.c | 9 +- fs/inode.c | 38 +++--- fs/notify/fsnotify.c | 9 +- fs/quota/dquot.c | 14 +- fs/super.c | 7 +- include/linux/dlock-list.h | 250 ++++++++++++++++++++++++++++++++++ include/linux/fs.h | 8 +- lib/Makefile | 2 +- lib/dlock-list.c | 325 +++++++++++++++++++++++++++++++++++++++++++++ 10 files changed, 617 insertions(+), 54 deletions(-) create mode 100644 include/linux/dlock-list.h create mode 100644 lib/dlock-list.c -- 1.8.3.1