linux-kernel - Re: CFS review

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: <Pine.LNX.4.64.0708011525560.1817@scrub.home>
Date:	Wed, 1 Aug 2007 15:33:17 +0200 (CEST)
From:	Roman Zippel <zippel@...ux-m68k.org>
To:	Andi Kleen <andi@...stfloor.org>
cc:	Mike Galbraith <efault@....de>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Ingo Molnar <mingo@...e.hu>,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel@...r.kernel.org
Subject: Re: CFS review

Hi,

On Wed, 1 Aug 2007, Andi Kleen wrote:

> > especially if one already knows that
> > scheduler clock has only limited resolution (because it's based on
> > jiffies), it becomes possible to use mostly 32bit values.
> 
> jiffies based sched_clock should be soon very rare. It's probably
> not worth optimizing for it.

I'm not so sure about that. sched_clock() has to be fast, so many archs 
may want to continue to use jiffies. As soon as one does that one can also 
save a lot of computational overhead by using 32bit instead of 64bit.
The question is then how easy that is possible.

bye, Roman
-
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/