From: Shakeel Butt <shakeelb@google.com>
To: Michal Hocko <mhocko@suse.com>
Cc: "zhaoyang.huang" <zhaoyang.huang@unisoc.com>,
Andrew Morton <akpm@linux-foundation.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Peter Zijlstra <peterz@infradead.org>,
Roman Gushchin <roman.gushchin@linux.dev>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
cgroups@vger.kernel.org,
Zhaoyang Huang <huangzhaoyang@gmail.com>,
ke.wang@unisoc.com
Subject: Re: [PATCH] mm: introduce entrance for root_mem_cgroup's current
Date: Thu, 2 Feb 2023 10:24:08 -0800 [thread overview]
Message-ID: <CALvZod5E0s9Vu3wq-Fuvs9z=ViMADn3aNL0f56ELGmFzxKCtkg@mail.gmail.com> (raw)
In-Reply-To: <Y9tz+0J9fw+Z+O+O@dhcp22.suse.cz>
On Thu, Feb 2, 2023 at 12:27 AM Michal Hocko <mhocko@suse.com> wrote:
>
> On Thu 02-02-23 12:32:57, zhaoyang.huang wrote:
> > From: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
> >
> > Introducing memory.root_current for the memory charges on root_mem_cgroup.
>
> Charges are not currently accounted for the root memcg universally. See
> try_charge which is used for all user space and skmem charges. I am not
> 100% sure about objcg based accounting because there is no explicit
> check for the root memcg but this might be hidden somewhere as well.
Yes in __get_obj_cgroup_from_memcg(). However the reason to use
try_charge_memcg() to bypass root check was to avoid the race with
reparenting. More details in c5c8b16b596e ("mm: memcontrol: fix
root_mem_cgroup charging").
>
> That means that the patch as is doesn't really provide and usable value.
> The root exemption has been removed in the past but that has been
> reverted due to a regression. See ce00a967377b ("mm: memcontrol: revert
> use of root_mem_cgroup res_counter") for more.
>
One advantage I can see is if someone is looking for usage for all top
containers (alive or zombie) but I wanted to know if that was the real
motivation behind the patch.
next prev parent reply other threads:[~2023-02-02 18:24 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-02 4:32 zhaoyang.huang
2023-02-02 6:30 ` Shakeel Butt
2023-02-02 6:36 ` Zhaoyang Huang
2023-02-02 8:27 ` Michal Hocko
2023-02-02 18:24 ` Shakeel Butt [this message]
2023-02-03 8:58 ` Michal Hocko
2023-02-03 19:18 ` Shakeel Butt
2023-02-03 17:42 ` Roman Gushchin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CALvZod5E0s9Vu3wq-Fuvs9z=ViMADn3aNL0f56ELGmFzxKCtkg@mail.gmail.com' \
--to=shakeelb@google.com \
--cc=akpm@linux-foundation.org \
--cc=cgroups@vger.kernel.org \
--cc=hannes@cmpxchg.org \
--cc=huangzhaoyang@gmail.com \
--cc=ke.wang@unisoc.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.com \
--cc=peterz@infradead.org \
--cc=roman.gushchin@linux.dev \
--cc=zhaoyang.huang@unisoc.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox