Instead of printing error messages like "I/O resource busy" which are
supplied by strerror, give better feedback if the reason of failure
is known.
E.g. taking the last cpu offline cannot succeed, therefore print a
message that gives this "hint".
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Use the common path access functions. In order to simplify chcpu also implement
and use path_writestr() which writes a string to the path specified.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reduce code duplication and print better error message if an
unsupported cpu number was passed.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
chcpu can modify the logical state of CPUs. It can enable and disable CPUs,
scan for new CPUs, change the CPU dispatching mode of the underlying
hypervisor and request (configure) or give logical CPUs back (deconfigure)
to the the underlying hypervisor.
This is quite useful if you work a lot with virtual servers, since doing all
the configuration stuff directly via sysfs becomes a pain.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>