ddi_get_lbolt(9f) [sunos man page]

ddi_get_lbolt(9F)					   Kernel Functions for Drivers 					 ddi_get_lbolt(9F)

NAME

       ddi_get_lbolt - returns the value of lbolt

SYNOPSIS

       #include <sys/types.h>
       #include <sys/ddi.h>
       #include <sys/sunddi.h>

       clock_t ddi_get_lbolt(void);

INTERFACE LEVEL

       Solaris DDI specific (Solaris DDI).

DESCRIPTION

       ddi_get_lbolt()	returns  the  value  of  lbolt	where  lbolt is an integer that represents the number of clock ticks since the last system
       reboot.	This value is used as a counter or timer inside the system kernel. The tick frequency can be determined by using  drv_usectohz(9F)
       which converts microseconds into clock ticks.

RETURN VALUES

       ddi_get_lbolt() returns the value of lbolt.

CONTEXT

	This routine can be called from any context.

SEE ALSO

       ddi_get_time(9F),  drv_getparm(9F), drv_usectohz(9F)

       Writing Device Drivers

	STREAMS Programming Guide

SunOS 5.10							    18 Feb 1998 						 ddi_get_lbolt(9F)

drv_hztousec(9F)					   Kernel Functions for Drivers 					  drv_hztousec(9F)

NAME

       drv_hztousec - convert clock ticks to microseconds

SYNOPSIS

       #include <sys/types.h>
       #include <sys/ddi.h>

       clock_t drv_hztousec(clock_t hertz);

INTERFACE LEVEL

       Architecture independent level 1 (DDI/DKI).

PARAMETERS

       hertz	The number of clock ticks to convert.

DESCRIPTION

       drv_hztousec() converts into microseconds the time expressed by hertz, which is in system clock ticks.

       The kernel variable lbolt, whose value should be retrieved by calling ddi_get_lbolt(9F), is the length of time the system has been up since
       boot and is expressed in clock ticks. Drivers often use the value of lbolt before and after an I/O request to measure the amount of time it
       took the device to process the request. drv_hztousec() can be used by the driver to convert the reading from clock ticks to a known unit of
       time.

RETURN VALUES

       The number of microseconds equivalent to the hertz parameter. No error value is returned. If the microsecond equivalent	to  hertz  is  too
       large to be represented as a clock_t, then the maximum clock_t value will be returned.

CONTEXT

       drv_hztousec() can be called from user or interrupt context.

SEE ALSO

       ddi_get_lbolt(9F), drv_usectohz(9F), drv_usecwait(9F)

       Writing Device Drivers

SunOS 5.10							    12 Nov 1992 						  drv_hztousec(9F)