From: Michal Hocko <mhocko@kernel.org>
To: Zhaoyang Huang <huangzhaoyang@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
Ingo Molnar <mingo@kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v1] ringbuffer: Don't choose the process with adj equal OOM_SCORE_ADJ_MIN
Date: Tue, 10 Apr 2018 08:14:47 +0200 [thread overview]
Message-ID: <20180410061447.GQ21835@dhcp22.suse.cz> (raw)
In-Reply-To: <CAGWkznG8-zmfE5iqPUVP+sztasa1zLPWE28qBiZ_tq524JznPw@mail.gmail.com>
On Tue 10-04-18 11:41:44, Zhaoyang Huang wrote:
> On Tue, Apr 10, 2018 at 11:12 AM, Steven Rostedt <rostedt@goodmis.org> wrote:
> > On Tue, 10 Apr 2018 10:32:36 +0800
> > Zhaoyang Huang <huangzhaoyang@gmail.com> wrote:
> >
> >> For bellowing scenario, process A have no intension to exhaust the
> >> memory, but will be likely to be selected by OOM for we set
> >> OOM_CORE_ADJ_MIN for it.
> >> process A(-1000) process B
> >>
> >> i = si_mem_available();
> >> if (i < nr_pages)
> >> return -ENOMEM;
> >> schedule
> >> --------------->
> >> allocate huge memory
> >> <-------------
> >> if (user_thread)
> >> set_current_oom_origin();
> >>
> >> for (i = 0; i < nr_pages; i++) {
> >> bpage = kzalloc_node
> >
> > Is this really an issue though?
> >
> > Seriously, do you think you will ever hit this?
> >
> > How often do you increase the size of the ftrace ring buffer? For this
> > to be an issue, the system has to trigger an OOM at the exact moment
> > you decide to increase the size of the ring buffer. That would be an
> > impressive attack, with little to gain.
> >
> > Ask the memory management people. If they think this could be a
> > problem, then I'll be happy to take your patch.
> >
> > -- Steve
> add Michael for review.
> Hi Michael,
> I would like suggest Steve NOT to set OOM_CORE_ADJ_MIN for the process
> with adj = -1000 when setting the user space process as potential
> victim of OOM.
OOM_SCORE_ADJ_MIN means "hide the process from the OOM killer completely".
So what exactly do you want to achieve here? Because from the above it
sounds like opposite things. /me confused...
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2018-04-10 6:14 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-08 2:16 [PATCH v1] ringbuffer: Don't choose the process with adj equal OOM_SCORE_ADJ_MIN Zhaoyang Huang
2018-04-08 3:48 ` Steven Rostedt
2018-04-08 5:54 ` Zhaoyang Huang
2018-04-08 12:47 ` Steven Rostedt
2018-04-09 0:56 ` Zhaoyang Huang
2018-04-09 13:49 ` Steven Rostedt
2018-04-10 0:32 ` Zhaoyang Huang
2018-04-10 2:32 ` Zhaoyang Huang
2018-04-10 3:12 ` Steven Rostedt
2018-04-10 3:41 ` Zhaoyang Huang
2018-04-10 6:14 ` Michal Hocko [this message]
2018-04-10 6:39 ` Zhaoyang Huang
2018-04-10 7:49 ` Michal Hocko
2018-04-10 8:04 ` Zhaoyang Huang
2018-04-10 8:12 ` Michal Hocko
2018-04-10 8:38 ` Zhaoyang Huang
2018-04-10 9:01 ` Michal Hocko
2018-04-10 9:32 ` Zhaoyang Huang
2018-04-10 9:51 ` Zhaoyang Huang
2018-04-10 10:49 ` Michal Hocko
2018-04-10 12:23 ` Steven Rostedt
2018-04-10 12:27 ` Michal Hocko
2018-04-10 12:36 ` Steven Rostedt
2018-04-10 13:13 ` Steven Rostedt
2018-04-10 13:14 ` Steven Rostedt
2018-04-10 16:45 ` Joel Fernandes
2018-04-10 18:00 ` Steven Rostedt
2018-04-10 18:39 ` Joel Fernandes
2018-04-10 19:05 ` Steven Rostedt
2018-04-11 7:48 ` Zhaoyang Huang
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