linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Tejun Heo <tj@kernel.org>
To: Waiman Long <longman@redhat.com>
Cc: Zefan Li <lizefan.x@bytedance.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Jonathan Corbet <corbet@lwn.net>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin <hpa@zytor.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Rafael J. Wysocki " <rafael@kernel.org>,
	Luis Chamberlain <mcgrof@kernel.org>,
	Kees Cook <keescook@chromium.org>,
	Iurii Zaikin <yzaikin@google.com>,
	x86@kernel.org, cgroups@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
	linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 0/4] cgroup/cpuset: Allow cpuset to bound displayed cpu info
Date: Mon, 14 Jun 2021 16:43:28 -0400	[thread overview]
Message-ID: <YMe/cGV4JPbzFRk0@slm.duckdns.org> (raw)
In-Reply-To: <20210614152306.25668-1-longman@redhat.com>

Hello,

On Mon, Jun 14, 2021 at 11:23:02AM -0400, Waiman Long wrote:
> The current container management system is able to create the illusion
> that applications running within a container have limited resources and
> devices available for their use. However, one thing that is hard to hide
> is the number of CPUs available in the system. In fact, the container
> developers are asking for the kernel to provide such capability.
> 
> There are two places where cpu information are available for the
> applications to see - /proc/cpuinfo and /sys/devices/system/cpu sysfs
> directory.
> 
> This patchset introduces a new sysctl parameter cpuset_bound_cpuinfo
> which, when set, will limit the amount of information disclosed by
> /proc/cpuinfo and /sys/devices/system/cpu.

The goal of cgroup has never been masquerading system information so that
applications can pretend that they own the whole system and the proposed
solution requires application changes anyway. The information being provided
is useful but please do so within the usual cgroup interface - e.g.
cpuset.stat. The applications (or libraries) that want to determine its
confined CPU availability can locate the file through /proc/self/cgroup.

Thanks.

-- 
tejun

  parent reply	other threads:[~2021-06-14 20:44 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20210614152306.25668-1-longman@redhat.com>
     [not found] ` <20210614152306.25668-5-longman@redhat.com>
2021-06-14 15:52   ` [PATCH 4/4] driver core: Allow showing cpu as offline if not valid in cpuset context Greg KH
2021-06-14 16:32     ` Waiman Long
2021-06-14 17:00       ` Greg KH
2021-06-14 20:43 ` Tejun Heo [this message]
2021-06-15  2:53   ` [PATCH 0/4] cgroup/cpuset: Allow cpuset to bound displayed cpu info Waiman Long
2021-06-15 15:59     ` Tejun Heo
2021-06-15  9:14   ` Christian Brauner

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=YMe/cGV4JPbzFRk0@slm.duckdns.org \
    --to=tj@kernel.org \
    --cc=bp@alien8.de \
    --cc=cgroups@vger.kernel.org \
    --cc=corbet@lwn.net \
    --cc=hannes@cmpxchg.org \
    --cc=keescook@chromium.org \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=lizefan.x@bytedance.com \
    --cc=longman@redhat.com \
    --cc=mcgrof@kernel.org \
    --cc=mingo@redhat.com \
    --cc=rafael@kernel.org \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.org \
    --cc=yzaikin@google.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;
as well as URLs for NNTP newsgroup(s).