numa_helper: add flag and min_nodes parameters to is_numa()

get_allowed_nodes() can fail if callers request more nodes than
are available. This patch changes is_numa() by adding a parameters
to it, which allows to easily check that system supports NUMA and
has at least certain number of nodes and it also updates tests
that used get_allowed_nodes() without checking node count first.

Signed-off-by: Jan Stancek <jstancek@redhat.com>
Acked-by: Cyril Hrubis <chrubis@suse.cz>
10 files changed