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: <alpine.DEB.2.00.1002041335140.6071@chino.kir.corp.google.com>
Date:	Thu, 4 Feb 2010 13:39:08 -0800 (PST)
From:	David Rientjes <rientjes@...gle.com>
To:	Jiri Kosina <jkosina@...e.cz>
cc:	Lubos Lunak <l.lunak@...e.cz>,
	Balbir Singh <balbir@...ux.vnet.ibm.com>,
	Rik van Riel <riel@...hat.com>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org,
	Andrew Morton <akpm@...ux-foundation.org>,
	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>,
	Nick Piggin <npiggin@...e.de>
Subject: Re: Improving OOM killer

On Thu, 4 Feb 2010, Jiri Kosina wrote:

> Why does OOM killer care about forkbombs *at all*?
> 

Because the cumulative effects of a forkbomb are detrimental to the 
system and the badness() heursitic favors large memory consumers very 
heavily.  Thus, the forkbomb is never really a strong candidate for oom 
kill since the parent may consume very little memory itself and meanwhile 
KDE or another large memory consumer will get innocently killed instead as 
a result.

> If we really want kernel to detect forkbombs (*), we'd have to establish 
> completely separate infrastructure for that (with its own knobs for tuning 
> and possibilities of disabling it completely).
> 

That's what we're trying to do, we can look at the shear number of 
children that the parent has forked and check for it to be over a certain 
"forkbombing threshold" (which, yes, can be tuned from userspace), the 
uptime of those children, their resident set size, etc., to attempt to 
find a sane heuristic that penalizes them.
--
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/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ