From: Michal Hocko <mhocko@suse.com>
To: Minchan Kim <minchan@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>,
linux-mm <linux-mm@kvack.org>
Subject: Re: [PATCH] mm: introduce oom_kill_disable sysctl knob
Date: Mon, 9 Nov 2020 08:37:06 +0100 [thread overview]
Message-ID: <20201109073706.GA12240@dhcp22.suse.cz> (raw)
In-Reply-To: <20201106203238.1375577-1-minchan@kernel.org>
On Fri 06-11-20 12:32:38, Minchan Kim wrote:
> It's hard to have some tests to be supposed to work under heavy
> memory pressure(e.g., injecting some memory hogger) because
> out-of-memory killer easily kicks out one of processes so system
> is broken or system loses the memory pressure state since it has
> plenty of free memory soon so.
I do not follow the reasoning here. So you want to test for a close to
no memory available situation and the oom killer stands in the way
because it puts a relief?
> Even though we could mark existing process's oom_adj to -1000,
> it couldn't cover upcoming processes to be forked for the job.
Why?
> This knob is handy to keep system memory pressure.
This sounds like a very dubious reason to introduce a knob to cripple
the system.
I can see some reason to control the oom handling policy because the
effect of the oom killer is really disruptive but a global on/off switch
sounds like a too coarse interface. Really what kind of production
environment would ever go with oom killer disabled completely?
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2020-11-09 7:37 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-06 20:32 [PATCH] mm: introduce oom_kill_disable sysctl knob Minchan Kim
2020-11-06 20:46 ` Randy Dunlap
2020-11-06 22:59 ` Minchan Kim
2020-11-09 7:37 ` Michal Hocko [this message]
2020-11-09 15:39 ` Minchan Kim
2020-11-09 16:06 ` Michal Hocko
2020-11-09 16:27 ` Minchan Kim
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