Stephane Eranian wrote on Fri, Mar 30, 2007 at 07:39:37AM -0800: > Hello, > > It seems that the kernel does not expose the Front-Side Bus (FSN) Clock > speed to user applications. I found code in the kernel dealing with > frequency scaling that extracts the information for x86 processors but > the value is never exposed. > > Knowledge the the FSB speed is very useful to monitoring tools. It is used > to compute certain bus-related metrics. > > Looking at the code, it seems that there is no standard way of extracting > the FSB speed. For each processor model, you have different MSRs. I would > think that the routines in the cpufreq code could be moved out and used > as the basis to expose the information somewhere in /sys.
That is still problematic as finding out the FSB might not be trivial. For example, for the NForce4 chipsets we have a too to manipulate FSB and multipliers, but it's not in the kernel and never will be. I don't think that K8 has a way to find the FSB from the CPU only, so you are bound to tangle with "nice" chipsets from NVidia et al. I like the idea, but I expect there will be reservations against presenting a /proc file that cannot be supported for almost all machines. In general, I would like the cpufreq code split up, as I need to reuse parts of it for other clock manipulation projects. Currently, cpufreq is a blob of code to manipulate frequencies, and to deal with the fallout. These two should be split up. Martin -- %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Martin Cracauer <cracauer@cons.org> http://www.cons.org/cracauer/ FreeBSD - where you want to go, today. http://www.freebsd.org/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
