From: David Miller <davem@davemloft.net>
To: yanhaishuang@cmss.chinamobile.com
Cc: xiyou.wangcong@gmail.com, kuznet@ms2.inr.ac.ru,
yoshfuji@linux-ipv6.org, edumazet@google.com,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] ipv4: Namespaceify tcp_max_orphans knob
Date: Fri, 08 Sep 2017 22:16:48 -0700 (PDT) [thread overview]
Message-ID: <20170908.221648.186026315535806669.davem@davemloft.net> (raw)
In-Reply-To: <E15E5C56-D712-4FEF-9AC5-AE28857D8D27@cmss.chinamobile.com>
From: 严海双 <yanhaishuang@cmss.chinamobile.com>
Date: Sat, 9 Sep 2017 13:09:57 +0800
>
>
>> On 2017年9月9日, at 下午12:35, Cong Wang <xiyou.wangcong@gmail.com> wrote:
>>
>> On Fri, Sep 8, 2017 at 6:25 PM, 严海双 <yanhaishuang@cmss.chinamobile.com> wrote:
>>>
>>>
>>>> On 2017年9月9日, at 上午6:13, Cong Wang <xiyou.wangcong@gmail.com> wrote:
>>>>
>>>> On Wed, Sep 6, 2017 at 8:10 PM, Haishuang Yan
>>>> <yanhaishuang@cmss.chinamobile.com> wrote:
>>>>> Different namespace application might require different maximal number
>>>>> of TCP sockets independently of the host.
>>>>
>>>> So after your patch we could have N * net->ipv4.sysctl_tcp_max_orphans
>>>> in a whole system, right? This just makes OOM easier to trigger.
>>>>
>>>
>>> From my understanding, before the patch, we had N * net->ipv4.sysctl_tcp_max_orphans,
>>> and after the patch, we could have ns1.sysctl_tcp_max_orphans + ns2.sysctl_tcp_max_orphans
>>> + ns3.sysctl_tcp_max_orphans, is that right? Thanks for your reviewing.
>>
>> Nope, by N I mean the number of containers. Before your patch, the limit
>> is global, after your patch it is per container.
>>
>
> Yeah, for example, if there is N containers, before the patch, I mean the limit is:
>
> N * net->ipv4.sysctl_tcp_max_orphans
>
> After the patch, the limit is:
>
> ns1. net->ipv4.sysctl_tcp_max_orphans + ns2. net->ipv4.sysctl_tcp_max_orphans + …
Not true.
Please remove "N" from your equation of the current situation.
"sysctl_tcp_max_orphans" applies to entire system, it is a global limit,
comparing one limit against all orphans in the system, there is no N.
next prev parent reply other threads:[~2017-09-09 5:16 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-07 3:10 [PATCH] ipv4: Namespaceify tcp_max_orphans knob Haishuang Yan
2017-09-08 22:13 ` Cong Wang
2017-09-09 1:25 ` 严海双
2017-09-09 4:35 ` Cong Wang
2017-09-09 5:09 ` 严海双
2017-09-09 5:16 ` David Miller [this message]
2017-09-09 10:21 ` 严海双
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=20170908.221648.186026315535806669.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=kuznet@ms2.inr.ac.ru \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=xiyou.wangcong@gmail.com \
--cc=yanhaishuang@cmss.chinamobile.com \
--cc=yoshfuji@linux-ipv6.org \
/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