v9: - Remove patch "llist: Allow optional sentinel node terminated lockless list" for now. This will be done as a follow-up patch. - Add a new lqueued field to blkg_iostat_set to store the status of whether lnode is in a lockless list. - Add a new patch 3 to speed up the freeing of blkcg by flushing out the rstat lockless lists at blkcg offline time. v8: - Update the llist patch to make existing llist functions and macros work for both NULL and sentinel terminated lockless list as much as possible and leave only the initialization and removal functions to have a sentinel terminated llist variants. v7: - Drop patch 1 ("blk-cgroup: Correctly free percpu iostat_cpu in blkg on error exit") as it is found to be unnecessary. - Add a new llist patch to provide a lockless list variant terminated by a sentinel node. - Modified patch 3 to use the new sllist API and move percpu_ref_put() later in the blkcg_rstat_flush() loop to prevent potential use-after-free problem. This patch series improves blkcg_rstat_flush() performance by eliminating unnecessary blkg enumeration and flush operations for those blkg's and blkg_iostat_set's that haven't been updated since the last flush. Waiman Long (3): blk-cgroup: Return -ENOMEM directly in blkcg_css_alloc() error path blk-cgroup: Optimize blkcg_rstat_flush() blk-cgroup: Flush stats at blkgs destruction path block/blk-cgroup.c | 103 +++++++++++++++++++++++++++++++++++------ block/blk-cgroup.h | 10 ++++ include/linux/cgroup.h | 1 + kernel/cgroup/rstat.c | 20 ++++++++ 4 files changed, 119 insertions(+), 15 deletions(-) -- 2.31.1