DRV_HZTOUSEC(9F)DRV_HZTOUSEC(9F)NAMEdrv_hztousec - convert clock ticks to microseconds
clock_t drv_hztousec(clock_t hertz);
Architecture independent level 1 (DDI/DKI).
The number of clock ticks to convert.
The drv_hztousec() function 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. The drv_hztousec() function can
be used by the driver to convert the reading from clock ticks to a
known unit of time.
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
The drv_hztousec() function can be called from user, interrupt, or ker‐
SEE ALSOddi_get_lbolt(9F), drv_usectohz(9F), drv_usecwait(9F)
Writing Device Drivers
Jan 16, 2006 DRV_HZTOUSEC(9F)