linux-kernel - Re: [PATCH 2.6.21 review I] [11/25] x86: default to physical mode on hotplug CPU kernels

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: <200702122336.23826.andi@firstfloor.org>
Date:	Mon, 12 Feb 2007 23:36:23 +0100
From:	Andi Kleen <andi@...stfloor.org>
To:	"Eric W. Biederman" <ebiederm@...ssion.com>
Cc:	Ingo Molnar <mingo@...e.hu>,
	Suresh Siddha <suresh.b.siddha@...el.com>,
	"Li, Shaohua" <shaohua.li@...el.com>, patches@...-64.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2.6.21 review I] [11/25] x86: default to physical mode on hotplug CPU kernels

On Sunday 11 February 2007 12:13, Eric W. Biederman wrote:
> Andi Kleen <ak@...e.de> writes:
> 
> > From: Ingo Molnar <mingo@...e.hu>
> >
> > Default to physical mode on hotplug CPU kernels.  Furher simplify and clean up
> > the APIC initialization code.
> 
> Where is the code that the subject describes?

True, that seems to be missing.

I agree that the patch seems to consist mostly of renaming doesn't make
it any easier to read.

And it's worrying that it doesn't handle the hotplug case at all.

> I have two problems here.
> 
> - I don't see anything handling the hotplug case, and forcing us to
>   physical mode.
> - Ingo's other patch asserts that hotplug should be made to handle
>   logical deliver mode.
> 
> With logical deliver mode the experimental evidence is that the
> destination cpu is a hint, 

What experimental evidence did you have? 

But I'm tempted to drop this unless the hotplug mystery can be cleared
up. There was past information that logical is unsafe for hotplug.

Ingo? Suresh? 

-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/