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H A D | intel_idle.c | 32e95180 Sat Feb 02 00:31:56 CST 2013 Len Brown <len.brown@intel.com> intel_idle: export both C1 and C1E
Here we disable HW promotion of C1 to C1E and export both C1 and C1E and distinct C-states.
This allows a cpuidle governor to choose a lower latency C-state than C1E when necessary to satisfy performance and QOS constraints -- and still save power versus polling. This also corrects the erroneous latency previously reported for C1E -- it is 10usec, not 1usec.
Note that if you use "intel_idle.max_cstate=N", then you must increment N by 1 to get the same behavior after this change.
Signed-off-by: Len Brown <len.brown@intel.com> 32e95180 Sat Feb 02 00:31:56 CST 2013 Len Brown <len.brown@intel.com> intel_idle: export both C1 and C1E Here we disable HW promotion of C1 to C1E and export both C1 and C1E and distinct C-states. This allows a cpuidle governor to choose a lower latency C-state than C1E when necessary to satisfy performance and QOS constraints -- and still save power versus polling. This also corrects the erroneous latency previously reported for C1E -- it is 10usec, not 1usec. Note that if you use "intel_idle.max_cstate=N", then you must increment N by 1 to get the same behavior after this change. Signed-off-by: Len Brown <len.brown@intel.com>
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