linux-kernel - Re: (ondemand) CPU governor regression between 2.6.23 and 2.6.24

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <200801272214.49928.toralf.foerster@gmx.de>
Date:	Sun, 27 Jan 2008 22:14:47 +0100
From:	Toralf Förster <toralf.foerster@....de>
To:	Mike Galbraith <efault@....de>
Cc:	Sam Ravnborg <sam@...nborg.org>, Ingo Molnar <mingo@...e.hu>,
	Peter Zijlstra <peterz@...radead.org>,
	linux-kernel@...r.kernel.org
Subject: Re: (ondemand) CPU governor  regression between 2.6.23 and 2.6.24

At Sunday 27 January 2008 Mike Galbraith wrote :
> 
> On Sun, 2008-01-27 at 13:39 +0100, Toralf Förster wrote:
> > Ough, does this mean that for a multi-user scenario of 2 non-root users "A" and
> > "B" each running exactly 1 process with nice level 0 and 19 rerspectively
> > that both share ~50% of the CPU *and furthermore* that that user "B" does never
> > ever have a  chance to be nice to user "A" although his process should really
> > use only those CPU cycles not eated by any other user ?
> 
> Yes.  If you want one task group to receive less cpu cycles, you have to
> 'nice' that task group by reducing it's share.

> I think it's better to just disable fair group scheduling if it doesn't
> suit your needs.  It's not going to be everyone's cup of tea.

Yes, disabling this kernel option is much better for me as a notebook user.

BTW t I've one more question related to this topic:

Is it correct that within the scenario described above user "A" never gets more
than 50% of the CPU as soon as user "B" is logged into the system (because of
the login process itself) ?

> 	-Mike
> 



-- 
MfG/Sincerely

Toralf Förster
pgp finger print: 7B1A 07F4 EC82 0F90 D4C2 8936 872A E508 7DB6 9DA3

Download attachment "signature.asc " of type "application/pgp-signature" (190 bytes)