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Message-ID: <20061015191716.15283.qmail@web27401.mail.ukl.yahoo.com>
Date: Sun, 15 Oct 2006 20:17:16 +0100 (BST)
From: ranjith kumar <ranjit_kumar_b4u@...oo.co.uk>
To: linux-kernel@...r.kernel.org
Subject: privilege levels and kernel mode
Hi,
I am using pentium-4 processor. My operating
system is Linux version 2.4.22-1.2199.nptl
I want to measure performance events like number of
memory reads, number of cache misses occured while
running a "C" program. For that I have to wright some
values into "Model specific registers of pentium-4
processor". But those registers can be written ONLY at
privilege level of zero of pentium4 processor.
We know that application programs we write (for
example any C program)are run at privilege
level-3(user mode).
I know how to include assembly instructions in a C
program to wtrite into "Model specific registers". But
that program has to be run at privilege level zero.
How to run a C program at privilege level zero??
Can any one help me?
Thanks in advance.
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