1*05687e49SSepherosa Ziehau.Dd February 17, 2014 2*05687e49SSepherosa Ziehau.Dt CLOCKMOD 4 3*05687e49SSepherosa Ziehau.Os 4*05687e49SSepherosa Ziehau.Sh NAME 5*05687e49SSepherosa Ziehau.Nm clockmod 6*05687e49SSepherosa Ziehau.Nd device driver for Intel software controlled clock modulation 7*05687e49SSepherosa Ziehau.Sh SYNOPSIS 8*05687e49SSepherosa ZiehauTo compile this driver into the kernel, 9*05687e49SSepherosa Ziehauplace the following line in your 10*05687e49SSepherosa Ziehaukernel configuration file: 11*05687e49SSepherosa Ziehau.Bd -ragged -offset indent 12*05687e49SSepherosa Ziehau.Cd "device clockmod" 13*05687e49SSepherosa Ziehau.Ed 14*05687e49SSepherosa Ziehau.Pp 15*05687e49SSepherosa ZiehauAlternatively, to load the driver as a 16*05687e49SSepherosa Ziehaumodule at boot time, place the following line in 17*05687e49SSepherosa Ziehau.Xr loader.conf 5 : 18*05687e49SSepherosa Ziehau.Bd -literal -offset indent 19*05687e49SSepherosa Ziehauclockmod_load="YES" 20*05687e49SSepherosa Ziehau.Ed 21*05687e49SSepherosa Ziehau.Sh DESCRIPTION 22*05687e49SSepherosa ZiehauThe 23*05687e49SSepherosa Ziehau.Nm 24*05687e49SSepherosa Ziehaudriver provides support for Intel software controlled clock modulation, 25*05687e49SSepherosa Ziehauwhich reduces CPU core's duty cycle to reduce the power consumption. 26*05687e49SSepherosa ZiehauA clock moduation domain contains logical CPUs on the same CPU core. 27*05687e49SSepherosa ZiehauAll logical CPUs in the same clock modulation domain will have the same 28*05687e49SSepherosa Ziehauduty cycle setting. 29*05687e49SSepherosa Ziehau.Sh MIB Variables 30*05687e49SSepherosa ZiehauClock modulation domain's information and controlling is provided by 31*05687e49SSepherosa Ziehau.Va machdep.clockmod_dom Ns Em X 32*05687e49SSepherosa Ziehaubranch of the 33*05687e49SSepherosa Ziehau.Xr sysctl 3 34*05687e49SSepherosa ZiehauMIB. 35*05687e49SSepherosa Ziehau.Bl -tag -width "available" 36*05687e49SSepherosa Ziehau.It Va members 37*05687e49SSepherosa ZiehauLogical CPUs belong to this clock modulation domain. 38*05687e49SSepherosa Ziehau.It Va available 39*05687e49SSepherosa ZiehauAvailable duty cycle settings for this clock modulation domain. 40*05687e49SSepherosa Ziehau.It Va select 41*05687e49SSepherosa ZiehauThe current duty cycle setting for this clock modulation domain. 42*05687e49SSepherosa ZiehauIt could be set to any value listed in 43*05687e49SSepherosa Ziehau.Va available . 44*05687e49SSepherosa ZiehauThe lower duty cycle the more power saving. 45*05687e49SSepherosa Ziehau.El 46*05687e49SSepherosa Ziehau.Sh SEE ALSO 47*05687e49SSepherosa Ziehau.Xr sysctl 3 , 48*05687e49SSepherosa Ziehau.Xr sysctl 8 49