Messages in this thread | | | Date | Sun, 15 Oct 2006 20:17:16 +0100 (BST) | From | ranjith kumar <> | Subject | privilege levels and kernel mode |
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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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