From: Vladimir Davydov <vdavydov@parallels.com>
To: Tejun Heo <tj@kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>, <linux-kernel@vger.kernel.org>,
<linux-mm@kvack.org>, <cgroups@vger.kernel.org>,
Li Zefan <lizefan@huawei.com>,
"David S. Miller" <davem@davemloft.net>,
Johannes Weiner <hannes@cmpxchg.org>,
Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Glauber Costa <glommer@gmail.com>,
Pavel Emelianov <xemul@parallels.com>,
Andrew Morton <akpm@linux-foundation.org>,
Greg Thelen <gthelen@google.com>,
Eric Dumazet <eric.dumazet@gmail.com>,
"Eric W. Biederman" <ebiederm@xmission.com>
Subject: Re: [PATCH RFC] memcg: revert kmem.tcp accounting
Date: Tue, 16 Sep 2014 12:38:10 +0400 [thread overview]
Message-ID: <20140916083810.GB32139@esperanza> (raw)
In-Reply-To: <20140916061401.GD805@mtj.dyndns.org>
On Tue, Sep 16, 2014 at 03:14:01PM +0900, Tejun Heo wrote:
> I don't think marking config options as "UNDER DEVELOPMENT" in its
> help documentation means anything. It's a rather silly thing to do.
> Not many people pay much attention to the help texts and once somebody
> somewhere enabled the option for a distro, it's as free in the wild as
> any other kernel feature and CONFIG_MEMCG_KMEM is enabled by a lot of
> distros. The same goes with the "debug" controller. It doesn't mean
> much that it has "debug" in its name. Once it's out in the wild,
> there will be someone making use of it in some weird way.
>
> If a debug feature has to be in the mainline kernel, the fact that
> it's a debug feature must be explicitly chosen in each use. IOW, gate
> it by an unwieldy boot param which makes it painfully clear that it's
> enabling an unstable debug feature and print out a loud warning
> message about it.
>
> As it currently stands, CONFIG_MEMCG_KMEM is as good as any other
> enabled kernel option. The help text saying that it's experimental
> does not mean anything especially when it doesn't even depend on
> CONFIG_BROKEN.
>
> So, the argument "the option was explained as experimental in help
> text" doesn't fly at all. We can still try to deprecate it gradually
> if the cleanup seems worthwhile; however, with v2 interface pending,
> I'm not sure how meaningful that'd be. We'd have to carry quite a bit
> of v1 code around anyway and I'd like to keep v1 interface as static
> as possible. No reason to shake that at this point.
Fair enough, thank you for the clarification. I hope we'll be able to
get rid of it in a year or two when cgroup v2 becomes stable.
Thanks,
Vladimir
next prev parent reply other threads:[~2014-09-16 8:38 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-12 15:26 [PATCH RFC] memcg: revert kmem.tcp accounting Vladimir Davydov
2014-09-12 17:18 ` Michal Hocko
2014-09-12 17:55 ` Tejun Heo
2014-09-12 21:43 ` Andrew Morton
2014-09-16 6:16 ` Tejun Heo
2014-09-15 7:42 ` Vladimir Davydov
2014-09-16 6:14 ` Tejun Heo
2014-09-16 8:38 ` Vladimir Davydov [this message]
2014-09-15 7:36 ` Vladimir Davydov
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