Messages in this thread | | | Date | Tue, 11 Feb 2014 11:22:38 +0100 | From | Michal Hocko <> | Subject | Re: [PATCH] memcg: change oom_info_lock to mutex |
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On Mon 10-02-14 13:40:55, David Rientjes wrote: > On Mon, 10 Feb 2014, Michal Hocko wrote: > > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > > index 19d5d4274e22..55e6731ebcd5 100644 > > --- a/mm/memcontrol.c > > +++ b/mm/memcontrol.c > > @@ -1687,7 +1687,7 @@ 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 > > */ > > - static DEFINE_SPINLOCK(oom_info_lock); > > + static DEFINE_MUTEX(oom_info_lock); > > struct cgroup *task_cgrp; > > struct cgroup *mem_cgrp; > > static char memcg_name[PATH_MAX]; > > @@ -1698,7 +1698,7 @@ void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) > > if (!p) > > return; > > > > - spin_lock(&oom_info_lock); > > + mutex_lock(&oom_info_lock); > > rcu_read_lock(); > > > > mem_cgrp = memcg->css.cgroup; > > @@ -1767,7 +1767,7 @@ done: > > > > pr_cont("\n"); > > } > > - spin_unlock(&oom_info_lock); > > + mutex_unlock(&oom_info_lock); > > } > > > > /* > > Can we change oom_info_lock() to only protecting memcg_name and forget > about interleaving the hierarchical memcg stats instead?
Why? Is mutex or holding it for the whole mem_cgroup_print_oom_info a big deal? I think that having clear oom report is really worth it.
-- Michal Hocko SUSE Labs
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