linux-kernel - Re: [PATCH] powernow-k8: depend on acpi-processor for SMP systems

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Message-ID: <20070517003733.GD16810@redhat.com>
Date:	Wed, 16 May 2007 20:37:33 -0400
From:	Dave Jones <davej@...hat.com>
To:	Joshua Hoblitt <jhoblitt@....hawaii.edu>
Cc:	Daniel Drake <dsd@...too.org>, duaneg@...da.com,
	prakash@...noor.de, linux-kernel@...r.kernel.org,
	Ed Sweetman <safemode2@...cast.net>, mark.langsdorf@....com
Subject: Re: [PATCH] powernow-k8: depend on acpi-processor for SMP systems

On Wed, May 16, 2007 at 02:26:14PM -1000, Joshua Hoblitt wrote:
 > I don't think this is quiet right either as Ed Sweetman has reported
 > that this issue doesn't occur on single socket/multi-core systems.

I'm not sure why [*], because this should be preventing it..

                if (num_online_cpus() != 1) {
                        printk(KERN_ERR PFX "MP systems not supported by PSB BIOS structure\n");
                        kfree(data);
                        return -ENODEV;
                }

num_online_cpus will return 2 in a dual-core system, even though there's
just one socket.  Given they share a power plane, if there's a valid
PSB structure however, it may be usable.  Though this isn't necessarily
true for all future dual-core AMD CPUs, and the ACPI tables really
should be preferred.

	Dave

[*] unless you have the second core disabled or CONFIG_SMP=n

-- 
http://www.codemonkey.org.uk
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