Differential D30982 Diff 91683 share/man/man9/hardclock.9

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share/man/man9/hardclock.9

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	.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR			.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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	.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)			.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE			.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	.\" POSSIBILITY OF SUCH DAMAGE.			.\" POSSIBILITY OF SUCH DAMAGE.
	.\"			.\"
	.Dd March 25, 2010			.Dd July 1, 2021
	.Dt HARDCLOCK 9			.Dt HARDCLOCK 9
	.Os			.Os
	.Sh NAME			.Sh NAME
	.Nm hardclock			.Nm hardclock
	.Nd real-time timer			.Nd real-time timer
	.Sh SYNOPSIS			.Sh SYNOPSIS
	.Ft void			.Ft void
	.Fn hardclock "int cnt" "int usermode"			.Fn hardclock "int cnt" "int usermode"
	.Sh DESCRIPTION			.Sh DESCRIPTION
	The			The
	.Fn hardclock			.Fn hardclock
	function is called			function is called periodically based on pending work.
				mavUnsubmitted Done Inline Actions This is too vague as for me. We could specify that it is called hz times per second when system is busy, but at least twice per second when idle. mav: This is too vague as for me. We could specify that it is called hz times per second when…
				impAuthorUnsubmitted Done Inline Actions hardclock is called adaptively based on pending work. The rate ranges from hz times a second for a very busy system, to as few as twice a second for an idle system. When calls at tick boundaries are omitted, cnt reflects an estimate of the number of elapsed ticks since the last call. Over the long haul, the sum of the cnt argument to this function over a second averages hz, however hz(9) has details important for short time scales. To replace everything in this section down to the usermode argument. imp: hardclock is called adaptively based on pending work. The rate ranges from hz times a second…
				The rate ranges from
				mavUnsubmitted Done Inline Actions "rate"? mav: "rate"?
				impAuthorUnsubmitted Done Inline Actions yes. Unless there's other changes, though, I'll not push an update to fix it (I've fixed it locally) imp: yes. Unless there's other changes, though, I'll not push an update to fix it (I've fixed it…
				.Va hz
				times per second on a very busy system, to twice a second on an idle system.
				The
				.Va cnt
				argument reports an estimate of the number of ticks since the last call.
				The sum of
				.Va cnt
				over a second averages
				.Va hz
				over the long haul.
				See
	.Xr hz 9			.Xr hz 9
	times per second.			for important details over shorter time scales.
	It implements the real-time system clock.
	The argument			The argument
	.Va cnt
	is the estimated number of ticks since the last call to
	.Fn hardclock .
	The argument
	.Va usermode			.Va usermode
	is none-zero when			is none-zero when
	.Fn hardclock			.Fn hardclock
	is called from a user-mode context.			is called from an context that interrupted usermode execution.
	.Pp			.Pp
	.Fn hardclock			.Fn hardclock
	may perform different tasks such as:			may perform different tasks such as:
	.Bl -bullet -offset indent			.Bl -bullet -offset indent
	.It			.It
	Run the current process's virtual and profile time (decrease the			Run the current process's virtual and profile time (decrease the
	corresponding timers, if they are activated, and generate			corresponding timers, if they are activated, and generate
	.Li SIGVTALRM			.Li SIGVTALRM
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	.Xr epoch 9			.Xr epoch 9
	processing.			processing.
	.El			.El
	.Sh SEE ALSO			.Sh SEE ALSO
	.Xr adjtime 2 ,			.Xr adjtime 2 ,
	.Xr ntp_adjtime 2 ,			.Xr ntp_adjtime 2 ,
	.Xr signal 3 ,			.Xr signal 3 ,
	.Xr ntpd 8 ,			.Xr ntpd 8 ,
	.Xr callout 9 ,
	.Xr hz 9			.Xr hz 9