linux-kernel - Re: [PATCH] oom: create a resource limit for oom

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: <20101114140237.E010.A69D9226@jp.fujitsu.com>
Date:	Sun, 14 Nov 2010 14:07:12 +0900 (JST)
From:	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>
To:	7eggert@....de
Cc:	kosaki.motohiro@...fujitsu.com,
	David Rientjes <rientjes@...gle.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
	Rik van Riel <riel@...hat.com>,
	Ying Han <yinghan@...gle.com>, linux-kernel@...r.kernel.org,
	gspencer@...omium.org, piman@...omium.org, wad@...omium.org,
	olofj@...omium.org, Linus Torvalds <torvalds@...ux-foundation.org>
Subject: Re: [PATCH] oom: create a resource limit for oom_adj

> > Hmm, at first glance that seems potentially dangerous if the current tab
> > generates a burt of memory allocations and it ends up killing all other
> > tabs before finally targeting the culprit whereas currently the heuristic
> > should do a good job of finding this problematic tab and killing it
> > instantly.
> 
> The original oom_adj design would e.g. adjust all background tabs to seem
> twice as bad as the current tab, so a ever-growing current tab would
> only be able to get one or two tabs killed in the worst case:
> 
> System is near OOM while the current tab starts using a normal amount of
> mem and grows beyond limits. After it easily killed the first bg tab by
> allocating one byte, it needs to grow to twice the normal tab memsize to
> start the OOM killer again. By then, it's score will be equal to normal
> background tabs (half size, double score), and killing the second tab will
> be luck. Killing the third tab should be impossible.
> 
> (If you adjust the bg tabs to be four times as killable, you'll get what
>  you asked for.)

Sorry for the delay. 

I've sent revert patch to linus. We DON'T want to break any userland seriously. 
So, we reconsider about this area. personally I hope to reintroduce oom_score_adj
later, but It must don't break current userland.



--
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/