https://docs.kernel.org/mm/page_tables.html
https://access.redhat.com/solutions/46111
https://lwn.net/Articles/423584/ 引入的历史
http://www.linux-kvm.org/images/9/9e/2010-forum-thp.pdf ; develper的展示
https://developers.redhat.com/blog/2021/04/27/benchmarking-transparent-versus-1gib-static-huge-page-performance-in-linux-virtual-machines#conclusion // 性能测试
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1703742
https://lists.ubuntu.com/archives/kernel-team/2017-July/085565.html
ubuntu 已经将always改成了madvice。