linux-kernel - Re: [PATCH 0/3] cpu: idle state framework for offline CPUs.

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: <20090810081941.GA18649@elf.ucw.cz>
Date:	Mon, 10 Aug 2009 10:19:41 +0200
From:	Pavel Machek <pavel@....cz>
To:	"Rafael J. Wysocki" <rjw@...k.pl>
Cc:	Shaohua Li <shaohua.li@...el.com>,
	Gautham R Shenoy <ego@...ibm.com>,
	Joel Schopp <jschopp@...tin.ibm.com>,
	"Brown, Len" <len.brown@...el.com>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Balbir Singh <balbir@...ibm.com>,
	"Pallipadi, Venkatesh" <venkatesh.pallipadi@...el.com>,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Ingo Molnar <mingo@...e.hu>,
	Vaidyanathan Srinivasan <svaidy@...ux.vnet.ibm.com>,
	Dipankar Sarma <dipankar@...ibm.com>,
	"Darrick J. Wong" <djwong@...ibm.com>,
	"linuxppc-dev@...ts.ozlabs.org" <linuxppc-dev@...ts.ozlabs.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 0/3] cpu: idle state framework for offline CPUs.

On Sun 2009-08-09 15:22:02, Rafael J. Wysocki wrote:
> On Sunday 09 August 2009, Pavel Machek wrote:
> > Hi!
> > 
> > > > Also, approaches such as [1] can make use of this
> > > > extended infrastructure instead of putting the CPU to an arbitrary C-state
> > > > when it is offlined, thereby providing the system administrator a rope to hang
> > > > himself with should he feel the need to do so.
> > > I didn't see the reason why administrator needs to know which state offline cpu
> > > should stay. Don't know about powerpc side, but in x86 side, it appears deepest
> > > C-state is already preferred.
> > > 
> > 
> > Agreed, deepest c-state is always best, there's no need to make it configurable.
> 
> Unless it doesn't work.

If it does not work, machine will not boot. We already have
max_cstate= kernel command line option to work around that...

									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
--
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/