Idea for these modification came up when css_set_lock seemed unneeded in cgroup_show_path. It's a delicate change, so the deciding factor was when cgroup_show_path popped up also in some profiles of frequent mountinfo readers. The idea is to trade the exclusive css_set_lock for the shared namespace_sem when rendering cgroup paths. Details are described more in individual commits. Michal Koutný (3): cgroup: Drop unused function for cgroup_path cgroup: Rely on namespace_sem in current_cgns_cgroup_from_root explicitly cgroup: Do not take css_set_lock in cgroup_show_path fs/namespace.c | 5 +++- include/linux/mount.h | 4 +++ kernel/cgroup/cgroup.c | 58 ++++++++---------------------------------- 3 files changed, 18 insertions(+), 49 deletions(-) -- 2.40.1