An unchecked todo
A reminder I set for myself, an essay scolding the young for their philosophy habit, and a message calling someone a “desperate illiterate.” I looked at the three of them together for a long time and came away without a conclusion.
Fewer pages. Harder claims.
Selected works and long-form writing, with short dated posts in between.
- Essays
- 05
- Series
- 01
- Projects
- 01
- Notes
- 03
- Since
- 2026
- Updated
- Elsewhere
- GitHub lr00rlorg roobliRSS
Latest
The newest writing open on the desk, then the three before it
All essays05Shared memory and the bank conflict
33 columns in a 32-wide shared tile, so a column read spreads across 32 banks instead of hitting one 32 times.
Kernels from zero
Why America builds productivity tools
54% of 2024 global software spend landed in the U.S., $368.5 billion.
saas中文
Apple product design as physics
ζ = 1 Critical damping: the fastest settle that still refuses to oscillate.
design
Series
Essays that come in parts, read in order
All series01Kernels from zero
One CUDA kernel, a matrix transpose, rewritten one idea at a time: first correct, then coalesced, then tiled, then measured.
Projects
Things built, each with a log of what changed
All projects01
CUDA C++ Course
Fifteen lessons and four in-browser GPU labs. English default, Chinese at /zh/. Finish without a local GPU; nine CUDA samples when you have one.
- Lessons
- 15
- Browser labs
- 4
- Samples
- 9
Latest in the log: Shared memory and the bank conflict
Notes
Short and dated, lighter than an essay
All notes03Every old URL still works
Essays moved from /writing/ to /essays/ and projects from /works/ to /projects/. Every earlier address still leads to its page in one hop, and the feed keeps the moved pages' old item IDs, so readers are not shown them again.
Reading time is counted, not guessed
The minutes on every page come from the page itself: words counted from the rendered text, code and math included, at 200 a minute, or Han characters at 400 a minute on Chinese pages.
The sidebar now knows what it lists
The tree beside every page used to be built in the browser from an index of titles and links. It is now rendered with the page, from the same data as the index, so it can show a series' progress, a note's date and a project's status.
Index
Every essay, newest first, numbered in the order it was published
- 005
An unchecked todo
A reminder I set for myself, an essay scolding the young for their philosophy habit, and a message calling someone a “desperate illiterate.” I looked at the three of them together for a long time and came away without a conclusion.
- 004
Why America builds productivity tools
Not ‘America loves Todoist.’ English-speaking professional strata, expensive labor, and ARR capital built a symptom market: micro-control for sale, responsibility sunk onto the self.
- 003
Apple product design as physics — springs, squircles, and hinge torque
Rubber-band bounce, continuous corners, and one-handed MacBook open are not taste. They are damping ratios, G2 curvature, and rigid-body torque inequalities you can model.
- 002
Keyboard shortcut systems — design, history, and a shared grammar
From Emacs prefixes and vi modes to Spotlight, command palettes, and Cmd+K: why power users treat keybindings as a namespace, and how KeyCombiner turns that into a practice system.
- 001
You can finish a CUDA course without a GPU — if the course is designed for it
What “no GPU required” actually covers, what each of the four browser labs deliberately cuts, and when you still need a real card and Nsight.
About
This site is English-first; some linked works (e.g. the CUDA course) also ship /zh/.