linux-kernel - Re: 2.6.23.8: OOM killer kills wrong jobs

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]

Message-ID: <20071217133053.508dbab0@the-village.bc.nu>
Date:	Mon, 17 Dec 2007 13:30:53 +0000
From:	Alan Cox <alan@...rguk.ukuu.org.uk>
To:	Steven Winikoff <smw@...or.concordia.ca>
Cc:	linux-kernel@...r.kernel.org,
	Sheila Ettinger <sheilae@...or.concordia.ca>,
	Tan Bui <tan@...or.concordia.ca>,
	Tao Wang <taow@...or.concordia.ca>,
	Gillian Roper <groper@...or.concordia.ca>,
	Sylvain Robitaille <syl@...or.concordia.ca>
Subject: Re: 2.6.23.8: OOM killer kills wrong jobs

> ...but I've run into a situation in which a system on which I *have* set
> no overcommit is being blasted by the OOM killer anyway.

Looks like the kernel is eating all the resources needed.

>    Linux babyalcor 2.6.23.1 #1 SMP Fri Oct 26 15:35:18 EDT 2007 \
>     i686 Dual Core AMD Opteron(tm) Processor 280 AuthenticAMD GNU/Linux

32bit kernel, 16GB of RAM. 

No suprise I'm afraid. Handling 16GB on a 32bit kernel, which has to
manage it all through a small addressible memory window is right on the
limit of what the standard kernel will handle (8GB is probably as high as
I would go). The no overcommit code ensures that user space doesn't
overcommit, but the kernel can get itself short of low memory resources
on a big box with 32bit kernels very easily. (In 64bit mode the CPU can
address all the memory directly so the problem vanishes).

You will *probably* get stable 16GB with the vendor tuned enterprise
kernels (RHEL, CentOS etc), or run a 64bit kernel and then the kernel
isn't trying the software equivalent of managing a filing cabinet through
the keyhole.

Alan
--
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/