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Subject: Re: finding out the boot cpu number from userspace
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Arjan van de Ven <arjanv@redhat.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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Date: Mon, 02 Aug 2004 15:13:55 +0100
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On Llu, 2004-08-02 at 13:16, Arjan van de Ven wrote:
> Hi,
> 
> assuming cpu 0 is the boot cpu sounds fragile/incorrect, but for irqbalanced
> I'd like to find out which cpu is the boot cpu, is there a good way of doing
> so ?
> 
> The reason for needing this is that some firmware only likes running on the
> boot cpu so I need to bind firmware-related irq's to that cpu ideally.

Grab the physical CPU id during boot up and stick it in the
/proc/cpuinfo as another information line "Boot device: Yes/no"

Just don't use "Processor" in the string or some glibc's start getting
strange ideas about the CPU count.