Hello, Waiman. On Wed, Jul 17, 2024 at 01:37:56PM -0400, Waiman Long wrote: > bis->sync is still being used in blk_cgroup_bio_start(). Replacing it with a > global lock may kill performance. We may have to use a per-cpu lock if we > want to go this route of eliminating bis->sync. So, the idea is to keep using u64_sync for blkg->iostat_cpu and use blkg_stat_lock for blkg->iostat. The former is the only one which is updated in hot path, right? Thanks. -- tejun