Messages in this thread Patch in this message | | | Date | Wed, 29 Jan 2014 13:09:07 +0100 | From | Michal Hocko <> | Subject | Re: [PATCH 6/8] cgroup: remove cgroup->name |
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On Tue 28-01-14 18:59:43, Tejun Heo wrote: > cgroup->name handling became quite complicated over time involving > dedicated struct cgroup_name for RCU protection. Now that cgroup is > on kernfs, we can drop all of it and simply use kernfs_name/path() and > friends. Replace cgroup->name and all related code with kernfs > name/path constructs. > > * Reimplement cgroup_name() and cgroup_path() as thin wrappers on top > of kernfs counterparts, which involves semantic changes. > pr_cont_cgroup_name() and pr_cont_cgroup_path() added. > > * cgroup->name handling dropped from cgroup_rename(). > > * All users of cgroup_name/path() updated to the new semantics. Users > which were formatting the string just to printk them are converted > to use pr_cont_cgroup_name/path() instead, which simplifies things > quite a bit. As cgroup_name() no longer requires RCU read lock > around it, RCU lockings which were protecting only cgroup_name() are > removed. > > Signed-off-by: Tejun Heo <tj@kernel.org> > Cc: Li Zefan <lizefan@huawei.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Johannes Weiner <hannes@cmpxchg.org> > Cc: Michal Hocko <mhocko@suse.cz> > Cc: Balbir Singh <bsingharora@gmail.com> > Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Nice. I hated the way how we retrieved the name previously. Acked-by: Michal Hocko <mhocko@suse.cz>
Btw. after this change we should drop part of the comment above oom_info_lock:
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 19d5d4274e22..d998baec5deb 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1684,8 +1684,7 @@ static void move_unlock_mem_cgroup(struct mem_cgroup *memcg, void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) { /* - * protects memcg_name and makes sure that parallel ooms do not - * interleave + * Makes sure that parallel ooms do not interleave */ static DEFINE_SPINLOCK(oom_info_lock); struct cgroup *task_cgrp; -- Michal Hocko SUSE Labs
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