The single-precision floating-point or double-precision floating-point has finite precision so loss of significance can happen and cause surprises.

This post shows the interaction between hugetlbfs and huge pages by an example program. All the results are based on linux 3.10.0-514.55.4.el7.x86_64.

In the Linux world, pid means two things. It’s the id of a process from POSIX’s point of view and the id of a task from kernel’s point of view.

Microbenchmark is used to measure the performance of a small piece of code for the purpose of performance optimization. Writing a good microbenchmark is hard and that’s why we should use microbenchmark frameworks (e.g. JMH for Java and Google Benchmark for C++) to help us. This post contains microbenchmarks that I think are interesting.

1. Get Java GC Related Application Stopped Time

Hit a Linux kernel bug that read() returns wrong data if it crosses a hugepage boundary.

我说我喜欢你的歌，我不知道这算不算是一件好事。 我说我喜欢你的词，总是道出我心中不欲人知的事。

SSH asks me to go way because of ntp clock skew

在南京大学软件学院读完本科后我到CMU读了硕士。虽然在CMU只有短短的一年半时间，但我还是从多个方面体验到了CMU（美国）的计算机教育。这其中有很多东西值得国内的高校学习借鉴。

Last semester, I took the course 15410 and wrote a kernel from scratch with my partner. I learned a lot from this course and the kernel project. Following is what I have learned:

1. Never Failed Functions
2. Comment on Why
3. Synchronization
4. Error Handling
5. Why Writing a Kernel From Scratch
6. Misc.