5e5fdcff28
Detecting zero page is not a light work, moving it to the thread to speed the main thread up, btw, handling ram_release_pages() for the zero page is moved to the thread as well Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Xiao Guangrong <xiaoguangrong@tencent.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com>