Messages in this thread | | | Date | Mon, 15 Mar 2010 14:50:13 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH 1/3] memcg: oom wakeup filter |
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On Fri, 12 Mar 2010 14:31:37 +0900 KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote:
> +static int memcg_oom_wake_function(wait_queue_t *wait, > + unsigned mode, int sync, void *arg) > +{ > + struct mem_cgroup *wake_mem = (struct mem_cgroup *)arg; > + struct oom_wait_info *oom_wait_info; > + > + /* both of oom_wait_info->mem and wake_mem are stable under us */ > + oom_wait_info = container_of(wait, struct oom_wait_info, wait); > + > + if (oom_wait_info->mem == wake_mem) > + goto wakeup; > + /* if no hierarchy, no match */ > + if (!oom_wait_info->mem->use_hierarchy || !wake_mem->use_hierarchy) > + return 0; > + /* check hierarchy */ > + if (!css_is_ancestor(&oom_wait_info->mem->css, &wake_mem->css) && > + !css_is_ancestor(&wake_mem->css, &oom_wait_info->mem->css)) > + return 0; > + > +wakeup: > + return autoremove_wake_function(wait, mode, sync, arg); > +}
What are the locking rules for calling css_is_ancestor()?
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