From: Michal Hocko <mhocko@kernel.org>
To: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>,
Andrew Morton <akpm@linux-foundation.org>,
Roman Gushchin <guro@fb.com>,
linux-mm@kvack.org, cgroups@vger.kernel.org,
linux-kernel@vger.kernel.org, kernel-team@fb.com
Subject: Re: [PATCH v2 3/3] mm: memcontrol: recursive memory.low protection
Date: Fri, 14 Feb 2020 16:13:18 +0100 [thread overview]
Message-ID: <20200214151318.GC31689@dhcp22.suse.cz> (raw)
In-Reply-To: <20200214135728.GK88887@mtj.thefacebook.com>
On Fri 14-02-20 08:57:28, Tejun Heo wrote:
[...]
Sorry to skip over a large part of your response. The discussion in this
thread got quite fragmented already and I would really like to conclude
to something.
> > I believe I have already expressed the configurability concern elsewhere
> > in the email thread. It boils down to necessity to propagate
> > protection all the way up the hierarchy properly if you really need to
> > protect leaf cgroups that are organized without a resource control in
> > mind. Which is what systemd does.
>
> But that doesn't work for other controllers at all. I'm having a
> difficult time imagining how making this one control mechanism work
> that way makes sense. Memory protection has to be configured together
> with IO protection to be actually effective.
Please be more specific. If the protected workload is mostly in-memory,
I do not really see how IO controller is relevant. See the example of
the DB setup I've mentioned elsewhere.
> As for cgroup hierarchy being unrelated to how controllers behave, it
> frankly reminds me of cgroup1 memcg flat hierarchy thing I'm not sure
> how that would actually work in terms of resource isolation. Also, I'm
> not sure how systemd forces such configurations and I'd think systemd
> folks would be happy to fix them if there are such problems. Is the
> point you're trying to make "because of systemd, we have to contort
> how memory controller behaves"?
No, I am just saying and as explained in reply to Johannes, there are
practical cases where the cgroup hierarchy reflects organizational
structure as well.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2020-02-14 15:13 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-19 20:07 [PATCH v2 0/3] mm: memcontrol: recursive memory protection Johannes Weiner
2019-12-19 20:07 ` [PATCH v2 1/3] mm: memcontrol: fix memory.low proportional distribution Johannes Weiner
2020-01-30 11:49 ` Michal Hocko
2020-02-03 21:21 ` Johannes Weiner
2020-02-03 21:38 ` Roman Gushchin
2019-12-19 20:07 ` [PATCH v2 2/3] mm: memcontrol: clean up and document effective low/min calculations Johannes Weiner
2020-01-30 12:54 ` Michal Hocko
2020-02-21 17:10 ` Michal Koutný
2020-02-25 18:40 ` Johannes Weiner
2020-02-26 16:46 ` Michal Koutný
2020-02-26 19:40 ` Johannes Weiner
2019-12-19 20:07 ` [PATCH v2 3/3] mm: memcontrol: recursive memory.low protection Johannes Weiner
2020-01-30 17:00 ` Michal Hocko
2020-02-03 21:52 ` Johannes Weiner
2020-02-10 15:21 ` Johannes Weiner
2020-02-11 16:47 ` Michal Hocko
2020-02-12 17:08 ` Johannes Weiner
2020-02-13 7:40 ` Michal Hocko
2020-02-13 13:23 ` Johannes Weiner
2020-02-13 15:46 ` Michal Hocko
2020-02-13 17:41 ` Johannes Weiner
2020-02-13 17:58 ` Johannes Weiner
2020-02-14 7:59 ` Michal Hocko
2020-02-13 13:53 ` Tejun Heo
2020-02-13 15:47 ` Michal Hocko
2020-02-13 15:52 ` Tejun Heo
2020-02-13 16:36 ` Michal Hocko
2020-02-13 16:57 ` Tejun Heo
2020-02-14 7:15 ` Michal Hocko
2020-02-14 13:57 ` Tejun Heo
2020-02-14 15:13 ` Michal Hocko [this message]
2020-02-14 15:40 ` Tejun Heo
2020-02-14 16:53 ` Johannes Weiner
2020-02-14 17:17 ` Tejun Heo
2020-02-17 8:41 ` Michal Hocko
2020-02-18 19:52 ` Johannes Weiner
2020-02-21 10:11 ` Michal Hocko
2020-02-21 15:43 ` Johannes Weiner
2020-02-25 12:20 ` Michal Hocko
2020-02-25 18:17 ` Johannes Weiner
2020-02-26 17:56 ` Michal Hocko
2020-02-21 17:12 ` Michal Koutný
2020-02-21 18:58 ` Johannes Weiner
2020-02-25 13:37 ` Michal Koutný
2020-02-25 15:03 ` Johannes Weiner
2020-02-26 13:22 ` Michal Koutný
2020-02-26 15:05 ` Johannes Weiner
2020-02-27 13:35 ` Michal Koutný
2020-02-27 15:06 ` Johannes Weiner
2019-12-19 20:22 ` [PATCH v2 0/3] mm: memcontrol: recursive memory protection Tejun Heo
2019-12-20 4:06 ` Roman Gushchin
2019-12-20 4:29 ` Chris Down
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