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:	Wed, 16 Apr 2008 07:31:10 -0700
From:	Arjan van de Ven <arjan@...radead.org>
To:	Andi Kleen <andi@...stfloor.org>
Cc:	Ingo Molnar <mingo@...e.hu>,
	Denys Vlasenko <vda.linux@...glemail.com>,
	linux-kernel@...r.kernel.org
Subject: Re: Does process need to have a kernel-side stack all the time?

On Wed, 16 Apr 2008 15:59:01 +0200
Andi Kleen <andi@...stfloor.org> wrote:

> 
> > well that and the fact that RH had customers who had major issues
> > at fewer threads with 8Kb versus fragmentation.
> > on 32 bit with a bunch of ram, there's just not enough lowmem
> > around to not have it fragmented to hell and back.
> 
> 2.6 VM has much more aggressive defrag heuristics than 2.4. That is
> what I meant with likely obsolete.

it's a question of very simple math though; both the space and the
amount of other pinnings mean you run into a wall.

2.6 is no doubt better, for sure it's better in freeing up memory etc.
It just can't be good enough.

(just to be clear, customers do run 30k threads workloads on 16Mb machines that
also have a sizable inode and dentry cache. you just cannot defragment that to the point
that you can use 8k stacks).




-- 
If you want to reach me at my work email, use arjan@...ux.intel.com
For development, discussion and tips for power savings, 
visit http://www.lesswatts.org
--
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