Posts

https://github.com/thegpvc/gpt-aria This was the most interesting prototype I’ve explored in my career so far, and I want to thank TheGP for sponsoring this project. Also thanks to Oleksandr Chugai who I partnered with on implementation and Ben Cmejla who helped with prompting. Inspiration I’ve been thinking about browser automation since the early days of my career when I worked at Firefox, where I got to work on performance problems and built things like Firefox Telemetry (Hi, HN haters!). With the rise of large language models (LLMs)—and OpenAI’s recent launch of ChatGPT plugins — things are getting exciting around user agents again. My favorite demo so far is natbot, Nat Friedman’s GPT-3-powered browser agent that he launched last October. ...

Cloudflare Pages 😍 I got into Cloudflare pages because it lets you host static websites with all the latest optimizations conveniently and for free. Setting up a static website with a custom domain is easy, and you get the benefits of automatic SSL, CDN, and latest version of HTTP3. This is how this blog is hosted and I have a few other projects like this. I love the fact that I can get a super-fast static website up and running in a few minutes and I don’t have to worry about infrastructure details. ...

TLDR: ZFS free-space reporting is a lagging indicator. Background I use Proxmox VM server backed by a ZFS array of hard drives for various personal infrastructure. I also have security cameras that upload motion-triggered videos to my server (via FTP!). Problem Description I would like to use 90% of my available space for most-recent security videos. Recipe: Create a dedicated ZFS volume Setup ZFS quota Run a cronjob to free space faster than it gets consumed by video uploads. I set out to find a decent disk-freeing solution. I eventually settled on a python free-disk. (Most of these utils were written in bash, didn’t want to disk having to grasp & modify write-only code). ...

Previous blog post on how to trace Firefox IO using bpftrace via official page_fault_user tracepoint left me a bit unsatisfied with how complicated it turned out. Complexity has potential to be error-prone and the syscall-tracing dependency makes it impossible to trace IO within the main executable. I decided to try reimplement the trace using my old approach of tracing ext4 functions that handle page-faults. This turned out to be much more robust. This is now documented on my github. It’s ugly in that it’s dependent on internal kernel structures, but it catches 100% of the IO and requires no post-trace syscall-correlation/fudging. ...

Modern browsers are some of the most complicated programs ever written. For example, the main Firefox library on my system is over 130Mbytes. Doing 130MB of IO poorly can be quite a performance hit, even with SSDs! :). Few people seem to understand how memory-mapped IO works. There are no pre-canned tools to observe it on Linux, thus even even fewer know how to observe it. Years ago, when I was working on Firefox startup performance, I discovered that libraries were loaded backwards (blog1, blog2, paper, GCC bug) on Linux. Figuring this out was super-painful, involved learning SystemTap and a setting up a just-right kernel with headers and symbols. ...