On 12/13/12 08:01, Hu Tao wrote:
This is merely a rebased version, so still tagged with v1.
The reason to disable cgroup cpuset by default is: currently,
sub-directories of cgroup cpuset won't be auto-updated if
cpu hot-plug happens. For example, if we now have 0-3,5-7 pcpus
online, the value of /sys/fs/cgroup/cpuset/libvirt/qemu/mydom/cpuset.cpus
is 0-3,5-7, then pcpu 4 is hot-plugged, but the value of cpuset.cpus
is still 0-3,5-7. This will cause a problem that we can't pin
to a hot-plugged pcpu.
Users can still enable cpuset by editing qemu.conf.
CPU hotplug isn't really a common thing in hosts right now. I'd rather
go for cpusets enabled by default and disabling them only if it poses
problems.
Peter