linux-kernel - Re: [PATCH 01/14] Introduce cpu_enabled

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]

Date:	Tue, 15 Jul 2008 12:03:27 +0200
From:	Andi Kleen <andi@...stfloor.org>
To:	Matthew Wilcox <matthew@....cx>
Cc:	Alex Chiang <achiang@...com>, linux-kernel@...r.kernel.org,
	linux-arch@...r.kernel.org, linux-acpi@...r.kernel.org
Subject: Re: [PATCH 01/14] Introduce cpu_enabled_map and friends

Matthew Wilcox <matthew@....cx> writes:
>
> I don't understand why we want to know about these CPUs.  Surely they
> should be 'possible', but not 'present'?  What useful thing can Linux do
> with them?

He explained it in the intro, near the end (I nearly complained about
this too when I hadn't finished reading it completely :):

|The big picture implication is that we can allow userspace
|to interact with disabled CPUs. In this particular example,
|we provide a knob that lets a sysadmin schedule any present
|CPU for firmware deconfiguration or enablement.

The reason sounds pretty exotic, but ok.

-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/