[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20111128133203.2d52ee28.kamezawa.hiroyu@jp.fujitsu.com>
Date: Mon, 28 Nov 2011 13:32:03 +0900
From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
To: Glauber Costa <glommer@...allels.com>
Cc: linux-kernel@...r.kernel.org, lizf@...fujitsu.com,
ebiederm@...ssion.com, davem@...emloft.net, paul@...lmenage.org,
gthelen@...gle.com, netdev@...r.kernel.org, linux-mm@...ck.org,
kirill@...temov.name, avagin@...allels.com, devel@...nvz.org,
eric.dumazet@...il.com, cgroups@...r.kernel.org
Subject: Re: [PATCH v6 10/10] Disable task moving when using kernel memory
accounting
On Fri, 25 Nov 2011 15:38:16 -0200
Glauber Costa <glommer@...allels.com> wrote:
> Since this code is still experimental, we are leaving the exact
> details of how to move tasks between cgroups when kernel memory
> accounting is used as future work.
>
> For now, we simply disallow movement if there are any pending
> accounted memory.
>
> Signed-off-by: Glauber Costa <glommer@...allels.com>
> CC: Hiroyouki Kamezawa <kamezawa.hiroyu@...fujitsu.com>
> ---
> mm/memcontrol.c | 23 ++++++++++++++++++++++-
> 1 files changed, 22 insertions(+), 1 deletions(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 2df5d3c..ab7e57b 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -5451,10 +5451,19 @@ static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
> {
> int ret = 0;
> struct mem_cgroup *mem = mem_cgroup_from_cont(cgroup);
> + struct mem_cgroup *from = mem_cgroup_from_task(p);
> +
> +#if defined(CONFIG_CGROUP_MEM_RES_CTLR_KMEM) && defined(CONFIG_INET)
> + if (from != mem && !mem_cgroup_is_root(from) &&
> + res_counter_read_u64(&from->tcp_mem.tcp_memory_allocated, RES_USAGE)) {
> + printk(KERN_WARNING "Can't move tasks between cgroups: "
> + "Kernel memory held. task: %s\n", p->comm);
> + return 1;
> + }
> +#endif
Hmm, the kernel memory is not guaranteed as being held by the 'task' ?
How about
"Now, moving task between cgroup is disallowed while the source cgroup
containes kmem reference." ?
Hmm.. we need to fix this task-move/rmdir issue before production use.
Thanks,
-Kame
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists