Re: [PATCH 2/3] qemu: Allow more generous cpuset.mems for vCPUs and IOThreads

The unit that cpuset CGroups controller works with is a thread/process, not individual memory allocations. Therefore, after we've set cpuset.mems for emulator (after previous commit it's set to union of all host NUMA nodes allowed for given domain), and as we try to set up cpuset.mems for vCPUs/IOThreads, memory is migrated to selected NUMA node(s). We are effectively saying: "this thread (vCPU thread) can have memory only from these NUMA node(s)". That's not really what we want though. The cpuset controller doesn't differentiate memory "belonging" to the emulator thread and vCPU thread or IOThread even. Therefore, set union of all allowed host NUMA nodes, just like we're doing for the emulator thread. Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2138150 Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt;