Frequency Scaling on Intel Core 2 Duo Processors

From: pradeep hettiarachchi
Date: Mon Oct 26 2009 - 11:06:48 EST


Hi,

I am working on a research in real-time systems. If I want to change
the frequency of the system as rapidly as possible, what is the best
method ? At the moment I write MSR_IA32_PERF_CTL, MSR directly with
the pre-found(calculated, encoded) values** for different frequencies.
I found the entire transition (latency) takes multiple milliseconds to
complete; however, I want some faster method to change the CPU
frequency.
Thank you in advance.


-Pradeep

** Initially I change the CPU frequency by some other method, such as
methods provided by an available user-space governor, and record the
MSR_IA32_PERF_STATUS values corresponding to that frequency. Later, I
change the relevant bits of MSR_IA32_PERF_CTL, with the values I got
previously, to achieve the relevant anticipated speed.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/