delphij's Chaos


20 Jan 2004

Preparing for an interview with David Xu

Today folks at FreeBSDChina suggested me to have an interview with FreeBSD’s David XU (Yifeng XU), who is an active committer, and possibly the only src committer living in the mainland China.

I have solicited the interview (through e-mail) several minutes before I wrote this blob. Now I am preparing questions for the interview. So if you have any suggestions, just write here and I will bring them together.

David Xu is mainly involved in the FreeBSD KSE Project. Kernel Scheduler Entities (KSE), is a kernel-supported threading system similar in design to Scheduler Activations [Anderson, et. al.]. It strikes a balance between user-level (1:N) and kernel-level (1:1) threading models, giving most of the advantages of both, and few of the disadvantages of either.

KSE’s threading library, a.k.a. libkse would became the default threading library before 5.3-RELEASE, which is also the branchpoint of 5-STABLE, and division of 5/6 branching. In the near future, a KSE aware scheduler, also known as the “ULE Scheduler”, designed and implemented by Jeff Roberson, will become the default kernel scheduler of FreeBSD-CURRENT. In my tests, KSE will bring significant performance improvements to Apache 2.x (worker MPM) and MySQL 4.x. I have built a threaded version of Postgresql as well however I am not sure how much performance improvements were gained because the database is not stressed.

Xu has also committed the GB2312 support. Xu became a src committer on September, 2002.