linux-kernel - Re: [patch] CFS scheduler, -v18

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] [day] [month] [year] [list]

Date:	04 Jul 2007 14:11:54 +0200
From:	Andi Kleen <andi@...stfloor.org>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	Mike Galbraith <efault@....de>,
	Vegard Nossum <vegard.nossum@...il.com>,
	Dmitry Adamushko <dmitry.adamushko@...il.com>,
	Linux Kernel <linux-kernel@...r.kernel.org>,
	Keith Packard <keith.packard@...el.com>
Subject: Re: [patch] CFS scheduler, -v18

Ingo Molnar <mingo@...e.hu> writes:
> 
> ah. That indeed makes sense. It seems like the xterm doesnt process the 
> Ctrl-C/Z keypresses _at all_ when it is 'spammed' with output. Normally, 
> output 'spam' is throttled by the scroll buffer's overhead. But in 
> Vegard's case, the printout involves a \r carriage return:
> 
>        printf("%ld\r", 1000 * clock() / CLOCKS_PER_SEC);
> 
> which allows xterm-spam (attached) to easily flood the xterm (without 
> any scrolling that would act as a throttle) and the xterm to flood Xorg. 
> 
> I suspect we need the help of an xterm/Xorg expert? (maybe Keith can 
> give us further pointers? I can reproduce the problem on a T60 with i940 
> and Core2Duo running Fedora 7 + Xorg 7.1.)

Xorg seems to have a couple of starvation issues. e.g. I found
the Gantt view in icemon during a busy compile session can starve all
other X clients for tenths of seconds.

-Andi
-
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/