Re: [-mm patch] Show memcg information during OOM

[Li Zefan <lizf@cn.fujitsu.com>]

> +void mem_cgroup_print_mem_info(struct mem_cgroup *memcg)
> +{
> +	printk(KERN_WARNING "Memory cgroups's name %s\n",
> +		memcg->css.cgroup->dentry->d_name.name);
> +	printk(KERN_WARNING "Memory cgroup RSS : usage %llu, limit %llu"
> +		" failcnt %llu\n", res_counter_read_u64(&memcg->res, RES_USAGE),

", failcnt %llu\n" ?

> +		res_counter_read_u64(&memcg->res, RES_LIMIT),
> +		res_counter_read_u64(&memcg->res, RES_FAILCNT));
> +	printk(KERN_WARNING "Memory cgroup swap: usage %llu, limit %llu "
> +		"failcnt %llu\n",

", failcnt %llu\n" ?

> +		res_counter_read_u64(&memcg->memsw, RES_USAGE),
> +		res_counter_read_u64(&memcg->memsw, RES_LIMIT),
> +		res_counter_read_u64(&memcg->memsw, RES_FAILCNT));
> +}
> +
>  /*
>   * Unlike exported interface, "oom" parameter is added. if oom==true,
>   * oom-killer can be invoked.
> diff --git a/mm/oom_kill.c b/mm/oom_kill.c
> index d3b9bac..b8e53ae 100644
> --- a/mm/oom_kill.c
> +++ b/mm/oom_kill.c
> @@ -392,6 +392,7 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
>  			current->comm, gfp_mask, order, current->oomkilladj);
>  		task_lock(current);
>  		cpuset_print_task_mems_allowed(current);
> +		mem_cgroup_print_mem_info(mem);

I think this can be put outside the task lock. The lock is used to call task_cs() safely in
cpuset_print_task_mems_allowed().

>  		task_unlock(current);
>  		dump_stack();
>  		show_mem();
>