Re: [libvirt] [PATCH 00/17] Supports for hypervisor-pin and hypervisor-bandwidth

On Tue, Aug 07, 2012 at 10:13:19AM -0600, Eric Blake wrote: > On 08/07/2012 09:47 AM, Daniel P. Berrange wrote: > > On Fri, Aug 03, 2012 at 02:36:02PM +0800, Hu Tao wrote: > >> This series is a merge of > >> > >> 1) "Support hypervisor-threads-pin in vcpupin" > >> (https://www.redhat.com/archives/libvir-list/2012-July/msg01361.html) > >> 2) "support to set cpu bandwidth for hypervisor threads" > >> (https://www.redhat.com/archives/libvir-list/2012-June/msg01161.html) > >> > >> to make life easier because of the two share some patches. > > > > This series is really focusing on pinning threads associated > > with the <emulator> element, rather than the hypervisor. The > > hypervisor is a separate entity that is shared. > > > > So I'm thinking that this entire patch series could replace > > 'hypervisor' with 'emulator' everywhere. Any one has agree > > or disagree ? > > I definitely agree - when I hear 'hypervisor', I think 'qemu:///system', > which is the technology used to run multiple guests, but when I hear > 'emulator', I think of a subset of a domain, namely the specific qemu > pid_t running a given guest. Also, we're not pinning all of the > hypervisor's threads, but just the threads that are associated with > emulation but not a specific vcpu. > > That is, marking up your comment in 1/17: > > cgroup mount point > +--libvirt <= setting up a namespace (*) > +--qemu <= hypervisor level > +--domain name <= domain level > +--vcpu0 <= vcpu level > ... > +--vcpuN > +--"hypervisor" <= emulator > > so a domain really is made up of an 'emulator' and 'vcpu' threads, and a > 'hypervisor' contains domains, rather than making up a portion of a domain. Also note that LXC has an emulator "/usr/libexec/libvirt_lxc" for which all these new APIs apply, but the term 'hypervisor' is meaningless for container based virt.