On 7 May 2014 23:20, Andreas Färber <afaer...@suse.de> wrote: > Am 07.05.2014 23:48, schrieb Peter Maydell: >> This is confusing. What is max_cpus > > Specified via -smp, defaults to actual CPUs.
I thought that was smp_cpus ... >> and why do we not >> just set max_cpus = machine->max_cpus ? > > For the PC, machine->max_cpus specifies the technical (APIC/ACPI/...) > upper limit, whereas -smp limits it to saner values. > > If you think KVM, then many machines today will have less than the > maximum number of CPUs and you may want to run multiple VMs and you may > not want their vCPUs competing too much for existing CPUs, so a limit > makes sense. That would imply that we want max_cpus = MIN(command_line_max_cpus, machine->max_cpus); thanks -- PMM
