From: Thomas Renninger <trenn@xxxxxxx> Date: Tue, Mar 23, 2010 at 04:12:18PM +0100 Hi Thomas, > would return the average freq of the last seconds, exactly the same > what you can do with cpufreq-aperf from userspace. > But if another user app does the same, it's messed up. > You can find out the pid of the process doing the cat and remember > aperf/mperf for it if it does not exist yet..., but now it gets to a > point where cpufreq-aperf is really more convenient and straight foward. > > Possibly documenting cpufreq-aperf in Documentation/cpu-freq would > be worth it. Also mentioning "boost" somewhere would be great: > grep -i boost Documentation/cpu-freq/ -r > Documentation/cpu-freq/pcc-cpufreq.txt:This is due to "turbo boost" ... > > Another idea is to have a separate cpufreq_avg_freq and update it on > every target() call, but that's overhead... you got me persuaded - if we want to have the effective frequency reported in the kernel, we have to come up with a slick solution that wouldn't incur overhead and won't be disrupted by others accessing those MSRs. Let's leave it to cpufreq-aperf for now and revisit this when needed. Thanks. -- Regards/Gruss, Boris. -- Advanced Micro Devices, Inc. Operating Systems Research Center -- To unsubscribe from this list: send the line "unsubscribe cpufreq" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
