On 6/11/20 8:54 PM, Daniel Henrique Barboza wrote:

This function handles the change of NUMA nodeset for a given guest, setting CpusetMems for the emulator, vcpus and IOThread sub-groups. It doesn't set the same nodeset to the root cgroup though. This means that cpuset.mems of the root cgroup ends up holding the new nodeset and the old nodeset as well. For a guest with placement=strict, nodeset='0', doing

virsh numatune <vm> 0 8 --live

Will make cpuset.mems of emulator, vcpus and iothread to be "8", but cpuset.mems of the root cgroup will be "0,8".

This means that any new tasks that ends up landing in the root cgroup, aside from the emulator/vcpus/iothread sub-groups, will be split between the old nodeset and the new nodeset, which is not what we want.

Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com> --- src/qemu/qemu_driver.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 88517ba6a7..59d322c8f3 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -9702,6 +9702,10 @@ qemuDomainSetNumaParamsLive(virDomainObjPtr vm, virCgroupFree(&cgroup_temp); }

+ /* set nodeset for root cgroup */ + if (virCgroupSetCpusetMems(priv->cgroup, nodeset_str) < 0) + goto cleanup; + ret = 0; cleanup: virCgroupFree(&cgroup_temp);

Reviewed-by: Michal Privoznik <mprivozn@redhat.com> and pushed. Michal