linux-kernel - Re: [patch -mm 4/9 v2] oom: remove compulsory panic_on

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 16 Feb 2010 15:54:50 -0800 (PST)
From:	David Rientjes <rientjes@...gle.com>
To:	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
cc:	Andrew Morton <akpm@...ux-foundation.org>,
	Rik van Riel <riel@...hat.com>,
	Nick Piggin <npiggin@...e.de>,
	Andrea Arcangeli <aarcange@...hat.com>,
	Balbir Singh <balbir@...ux.vnet.ibm.com>,
	Lubos Lunak <l.lunak@...e.cz>,
	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>,
	linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: Re: [patch -mm 4/9 v2] oom: remove compulsory panic_on_oom mode

On Wed, 17 Feb 2010, KAMEZAWA Hiroyuki wrote:

> Please don't. I had a chance to talk with customer support team and talked
> about panic_on_oom briefly. I understood that panic_on_oom_alyways+kdump
> is the strongest tool for investigating customer's OOM situtation and do
> the best advice to them. panic_on_oom_always+kdump is the 100% information
> as snapshot when oom-killer happens. Then, it's easy to investigate and
> explain what is wront. They sometimes discover memory leak (by some prorietary
> driver) or miss-configuration of the system (as using unnecessary bounce buffer.)
> 

Ok, I'm not looking to cause your customers unnecessary grief by removing 
an option that they use, even though the same effect is possible by 
setting all tasks to OOM_DISABLE.  I'll remove this patch in the next 
revision.

> Then, please leave panic_on_oom=always.
> Even with mempolicy or cpuset 's OOM, we need panic_on_oom=always option.
> And yes, I'll add something similar to memcg. freeze_at_oom or something.
> 

Memcg isn't a special case here, it should also panic the machine if 
panic_on_oom == 2, so if we aren't going to remove this option then I 
agree with Nick that we need to panic from mem_cgroup_out_of_memory() as 
well.  Some users use cpusets, for example, for the same effect of memory 
isolation as you use memcg, so panicking in one scenario and not the other 
is inconsistent.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/