Home
last modified time | relevance | path

Searched hist:"32 e95180" (Results 1 – 1 of 1) sorted by relevance

/openbmc/linux/drivers/idle/
H A Dintel_idle.c32e95180 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>