.TH COREUPDOWND 1 COREUPDOWN
.SH MAME
coreupdownd - Dynamically enable and disable CPU's to only use one during low CPU usage
.SH SYNPOSIS
.B coreupdownd
.RI "[-C " coreup-cooldown-time ]
.RI "[-c " coredown-cooldown-time ]
.RI "[-i " check-interval ]
.RI "[-s " configuration-file ]
.RI "[-T " coreup-cpu-usage-time-consistency-threshold ]
.RI "[-t " coredown-cpu-usage-time-consistency-threshold ]
.RI "[-U " coreup-cpu-usage-threshold ]
.RI "[-u " coredown-cpu-usage-threshold ]
.RI "[-X " post-coreup-command ]
.RI "[-x " post-coredown-command ]
[-ef]
.SH DESCRIPTION
The
.B coreupdownd
daemon dynamically turns all CPU cores, except except
the main one, on and off depending on CPU usage.
.PP
The daemon periodically determines what the CPU usage
would be if only the main CPU core was enable. If it
would be saturated, the other cores are enabled, otherwise
the they are disabled.
.PP
This is designed as a workaround for virtual machines
that have input performance issues (keyboard input lag
and keys getting stuck) when more than one CPU core is
online.
.SH OPTIONS
The
.B coreupdownd
daemon shall conform to the Base Definitions volume of
POSIX.1-2017, Section 12.2, Utility Syntax Guidelines.
.PP
The following options are supported:
.TP
.BI "-C " coreup-cooldown-time
The amount of time, measured in (integer) multiples of the
.IR check-interval ,
before the daemon may disable CPU's after enabling CPU's.
During this time, time is not counted toward
.IR coredown-cpu-usage-threshold .
.TP
.BI "-c " coredown-cooldown-time
The amount of time, measured in (integer) multiples of the
.IR check-interval ,
before the daemon may enable CPU's after disabling CPU's.
During this time, time is not counted toward
.IR coreup-cpu-usage-threshold .
.TP
.B -e
Do not close standard error at end of initialisation.
.TP
.B -f
Do not daemonise. (The standard input and standard
output will still be closed when the process has
completed it's initialisation.)
Implies
.BR -e .
.TP
.BI "-i " check-interval
The interval, in seconds (need not be integer), with
which the daemon periodically checks the CPU usage.
.TP
.BI "-s " configuration-file
Configuration file to read instead of
.BR /etc/coreupdownd.conf .
.TP
.BI "-T " coreup-cpu-usage-time-consistency-threshold
The amount of time, measure in (integer) multiples of the
.I check-interval
the CPU usage must have stayed at or above
.I coreup-cpu-usage-threshold
before the daemon may enable all CPU's.
.TP
.BI "-t " coredown-cpu-usage-time-consistency-threshold
The amount of time, measured in (integer) multiples of the
.IR check-interval ,
the CPU usage must have stayed at or below
.I coredown-cpu-usage-threshold
before the daemon may disable all CPU's except the main core .
.TP
.BI "-U " coreup-cpu-usage-threshold
The required CPU usage (integer lower bound) before the
daemon may enable all CPU's.
.TP
.BI "-u " coredown-cpu-usage-threshold
The required CPU usage (integer upper bound) before the
daemon may disable all CPU's except the main core.
.TP
.BI "-X " post-coreup-command
Run
.I post-coreup-command
in
.BR sh (1)
after each time all CPU's are enabled.
.TP
.BI "-x " post-coredown-command
Run
.I post-coredown-command
in
.BR sh (1)
after each time all non-main CPU's are disabled.
.SH OPERANDS
No operands are supported.
.SH STDIN
The
.B coreupdownd
daemon does not use the standard input, however
it will be closed by the daemon once initialisation
has completed.
.SH INPUT FILES
None.
.SH ENVIRONMENT VARIABLES
No environment variables affects the execution of
.BR coreupdownd .
.SH ASYNCHRONOUS EVENTS
If the
.B coreupdownd
utility traps the following signals:
.TP
.B SIGHUP
Causes the daemon reload it's configurations, and
attempt to update to the newest installed version
of the daemon.
.SH STDOUT
The
.B coreupdownd
daemon does not use the standard output, however
it will be closed by the daemon once initialisation
has completed.
.SH STDERR
The standard error is used for diagnostic messages.
.SH OUTPUT FILES
None.
.SH EXTENDED DESCRIPTION
None.
.SH EXIT STATUS
If the
.B coreupdownd
daemon only terminates on failure, in which case
the exit status will be:
.TP
1
An error occurred.
.SH CONSEQUENCES OF ERRORS
Default.
.SH APPLICATION USAGE
None.
.SH EXAMPLES
None.
.SH RATIONALE
None.
.SH NOTES
None.
.SH BUGS
None.
.SH FUTURE DIRECTIONS
None.
.SH SEE ALSO
.BR coreupdownd.conf (5),
.BR coreup (1),
.BR coredown (1)
