I have a box running 3.9.4. For a few hundred ms, all packages and cores* exceeded their power limits, and then they all came back to normal.
Since then, turbo boost went away. The first thing I tried was writing 0 to msr 0x19C to clear the throttling "log" bit. The bit was clear, but still no turbo. (I only did this on one package to avoid destroying information.) I have the performance governor set, so there are never any software-initiated performance transitions. As an experiment, I switched core 0 to powersave (aka very low frequency) and then back to performance. The entire package's turbo came back. I did the same thing to the cores on package 1 (all of them, sorry), and that package's turbo boost came back. Does the kernel need to reprogram CPU frequencies after thermal/power throttling conditions clear? My CPUs are: processor : 31 vendor_id : GenuineIntel cpu family : 6 model : 45 model name : Intel(R) Xeon(R) CPU E5-2690 0 @ 2.90GHz stepping : 7 microcode : 0x710 * Slight lie here. CPU18 exceeded core limit but not power limit. -- 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/
