From mboxrd@z Thu Jan  1 00:00:00 1970
From: Frederic Weisbecker <fweisbec-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Subject: Re: [PATCH v3 16/28] memcg: kmem controller charge/uncharge
 infrastructure
Date: Wed, 30 May 2012 14:34:08 +0200
Message-ID: <20120530123406.GC25094@somewhere.redhat.com>
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To: Glauber Costa <glommer-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org, Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>, Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>, Greg Thelen <gthelen-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>, Suleiman Souhlal <suleiman-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>, Michal Hocko <mhocko-AlSwsSmVLrQ@public.gmane.org>, Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>, devel-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org, David Rientjes <rientjes-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>, Christoph Lameter <cl-vYTEC60ixJUAvxtiuMwx3w@public.gmane.org>, Pekka Enberg <penberg-bbCR+/B0CizivPeTLB3BmA@public.gmane.org>

On Fri, May 25, 2012 at 05:03:36PM +0400, Glauber Costa wrote:
> +bool __mem_cgroup_new_kmem_page(struct page *page, gfp_t gfp)
> +{
> +	struct mem_cgroup *memcg;
> +	struct page_cgroup *pc;
> +	bool ret = true;
> +	size_t size;
> +	struct task_struct *p;
> +
> +	if (!current->mm || in_interrupt())
> +		return true;
> +
> +	rcu_read_lock();
> +	p = rcu_dereference(current->mm->owner);
> +	memcg = mem_cgroup_from_task(p);

So this takes the memcg of the group owner rather than the
task? I understand why we want this for user memory, but for
kernel?