From: Michal Hocko <mhocko@kernel.org>
To: Zhaoyang Huang <huangzhaoyang@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
Ingo Molnar <mingo@kernel.org>,
linux-kernel@vger.kernel.org, kernel-patch-test@lists.linaro.org,
Andrew Morton <akpm@linux-foundation.org>,
Joel Fernandes <joelaf@google.com>,
linux-mm@kvack.org, Vlastimil Babka <vbabka@suse.cz>
Subject: Re: [PATCH v1] kernel/trace:check the val against the available mem
Date: Wed, 4 Apr 2018 08:23:40 +0200 [thread overview]
Message-ID: <20180404062340.GD6312@dhcp22.suse.cz> (raw)
In-Reply-To: <CAGWkznH-yfAu=fMo1YWU9zo-DomHY8YP=rw447rUTgzvVH4RpQ@mail.gmail.com>
On Wed 04-04-18 10:58:39, Zhaoyang Huang wrote:
> On Tue, Apr 3, 2018 at 9:56 PM, Michal Hocko <mhocko@kernel.org> wrote:
> > On Tue 03-04-18 09:32:45, Steven Rostedt wrote:
> >> On Tue, 3 Apr 2018 14:35:14 +0200
> >> Michal Hocko <mhocko@kernel.org> wrote:
> > [...]
> >> > Being clever is OK if it doesn't add a tricky code. And relying on
> >> > si_mem_available is definitely tricky and obscure.
> >>
> >> Can we get the mm subsystem to provide a better method to know if an
> >> allocation will possibly succeed or not before trying it? It doesn't
> >> have to be free of races. Just "if I allocate this many pages right
> >> now, will it work?" If that changes from the time it asks to the time
> >> it allocates, that's fine. I'm not trying to prevent OOM to never
> >> trigger. I just don't want to to trigger consistently.
> >
> > How do you do that without an actuall allocation request? And more
> > fundamentally, what if your _particular_ request is just fine but it
> > will get us so close to the OOM edge that the next legit allocation
> > request simply goes OOM? There is simply no sane interface I can think
> > of that would satisfy a safe/sensible "will it cause OOM" semantic.
> >
> The point is the app which try to allocate the size over the line will escape
> the OOM and let other innocent to be sacrificed. However, the one which you
> mentioned above will be possibly selected by OOM that triggered by consequnce
> failed allocation.
If you are afraid of that then you can have a look at {set,clear}_current_oom_origin()
which will automatically select the current process as an oom victim and
kill it.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2018-04-04 6:23 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-29 10:41 [PATCH v1] kernel/trace:check the val against the available mem Zhaoyang Huang
2018-03-29 16:05 ` Steven Rostedt
2018-03-30 3:32 ` Zhaoyang Huang
2018-03-30 14:07 ` Steven Rostedt
2018-03-30 6:53 ` [Kernel-patch-test] " kbuild test robot
2018-03-30 6:54 ` kbuild test robot
2018-03-30 14:20 ` Steven Rostedt
2018-03-30 16:37 ` Joel Fernandes
2018-03-30 19:10 ` Steven Rostedt
2018-03-30 20:37 ` Joel Fernandes
2018-03-30 20:53 ` Matthew Wilcox
2018-03-30 21:30 ` Steven Rostedt
2018-03-30 21:42 ` Steven Rostedt
2018-03-30 23:38 ` Joel Fernandes
2018-03-31 1:41 ` Steven Rostedt
2018-03-31 2:18 ` Matthew Wilcox
2018-03-31 3:07 ` Steven Rostedt
2018-03-31 5:44 ` Joel Fernandes
2018-04-02 0:52 ` Zhaoyang Huang
2018-04-03 11:06 ` Michal Hocko
2018-04-03 11:51 ` Steven Rostedt
2018-04-03 12:16 ` Michal Hocko
2018-04-03 12:23 ` Steven Rostedt
2018-04-03 12:35 ` Michal Hocko
2018-04-03 13:32 ` Steven Rostedt
2018-04-03 13:56 ` Michal Hocko
2018-04-03 14:17 ` Steven Rostedt
2018-04-03 16:11 ` Michal Hocko
2018-04-03 16:59 ` Steven Rostedt
2018-04-03 22:56 ` Steven Rostedt
2018-04-04 6:20 ` Michal Hocko
2018-04-04 12:21 ` Joel Fernandes
2018-04-04 12:59 ` Steven Rostedt
2018-04-04 14:10 ` Michal Hocko
2018-04-04 14:25 ` Steven Rostedt
2018-04-04 14:42 ` Michal Hocko
2018-04-04 15:04 ` Steven Rostedt
2018-04-04 15:27 ` Michal Hocko
2018-04-04 15:38 ` Steven Rostedt
2018-04-04 2:58 ` Zhaoyang Huang
2018-04-04 6:23 ` Michal Hocko [this message]
2018-04-04 9:29 ` Zhaoyang Huang
2018-04-04 14:11 ` Steven Rostedt
2018-04-04 14:23 ` Michal Hocko
2018-04-04 14:31 ` Steven Rostedt
2018-04-04 14:47 ` Michal Hocko
2018-04-04 15:47 ` Steven Rostedt
2018-04-05 2:58 ` Matthew Wilcox
2018-04-05 4:12 ` Joel Fernandes
2018-04-05 14:22 ` Matthew Wilcox
2018-04-05 14:27 ` Michal Hocko
2018-04-05 14:34 ` Steven Rostedt
2018-04-05 15:13 ` Matthew Wilcox
2018-04-05 15:32 ` Michal Hocko
2018-04-05 16:15 ` Matthew Wilcox
2018-04-05 18:54 ` Michal Hocko
2018-04-05 20:15 ` __GFP_LOW Matthew Wilcox
2018-04-06 6:09 ` __GFP_LOW Michal Hocko
2018-04-08 4:27 ` __GFP_LOW Matthew Wilcox
2018-04-09 7:34 ` __GFP_LOW Michal Hocko
2018-04-09 15:51 ` __GFP_LOW Matthew Wilcox
2018-04-09 18:14 ` __GFP_LOW Michal Hocko
[not found] ` <CA+JonM0HG9kWb6-0iyDQ8UMxTeR-f=+ZL89t5DvvDULDC8Sfyw@mail.gmail.com>
2018-04-10 12:19 ` __GFP_LOW Matthew Wilcox
2018-04-05 14:30 ` [PATCH v1] kernel/trace:check the val against the available mem Steven Rostedt
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