Message-ID: <47AA554E.7050405@zytor.com>
Date: Wed, 06 Feb 2008 16:48:14 -0800
From: "H. Peter Anvin" <hpa@zytor.com>
User-Agent: Thunderbird 2.0.0.9 (X11/20071115)
MIME-Version: 1.0
To: Hasan Rashid <hasan@digitalpath.net>
CC: "'Maxim Levitsky'" <maximlevitsky@gmail.com>, linux-kernel@vger.kernel.org
Subject: Re: Access MSR functions in userspace?
References: <200802070037.m170b4Bb000579@terminus.zytor.com>
In-Reply-To: <200802070037.m170b4Bb000579@terminus.zytor.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1006
Lines: 26

Hasan Rashid wrote:
> Maxim, HPA,
> 
>  I loaded the module msr.o and when I try to use wrmsr or rdmsr from the msr
> tools I get rdmsr: open: No such device. It seems like device doesn't
> register upon module load. I have created the devices on the system using
> mknod. Meaning /dev/cpu/msr is there and I changed the appropriate path in
> the msr.c(module) and wrmsr.c (utlity) file. 
> 
> What would prompt this error message?
> 

/dev/cpu/msr is bogus.  It should be /dev/cpu/0/msr etc.

Sounds like your version of udev might be out of date, or you're using 
an old kernel which doesn't communicate /dev/cpu/* to udev properly.

Revert your hacks and, if you have to create the nodes manually, use the 
MAKEDEV script included with the msr-tools.

	-hpa
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/