Top all-time · #8732
dxu's blog
Personal blog · dxuuu.xyzsystemsprogramming
dxu's blog is a personal blog at dxuuu.xyz about systems and programming. Since 2017, 9 different Hacker News readers have linked it 26 times, most often “Packet drop reasons (Linux kernel)”. It is still writing: the last post was on 2026-01-01, and you can follow it by feed.
Too few sampled comments (1) to say how often HN recommends it.?
Why HN links it
HN readers link dxu's blog for a post on C "truthiness", explaining how boolean values sit in registers under the 64-bit SysV ABI and how compilers rely on the lowest bit.
Summarised by Claude from a sample of 1 HN comments that link here. Each comment is marked recommending, critical or neutral (citing without judging); how this works.
Most-linked posts?
- Packet drop reasons (Linux kernel)2 people · 2 mentions · first linked 2023-09-19
- Bpfilter Is Forever2 people · 2 mentions · first linked 2023-07-26
- Libbpf-rs: eBPF for the Rust ecosystem2 people · 2 mentions · first linked 2021-01-07
- PRR – a terminal tool for managing Pull Requests on GitHub2 people · 2 mentions · first linked 2022-07-31
What Hacker News says?
BPF_PROG_RUN is great but unfortunately depends on the running kernel version. To that end, I wrote `vmtest` ( https://dxuuu.xyz/vmtest.html ) which is designed for the BPF_PROG_RUN use case.
Comment linking /vmtest.html
on “Unit Testing eBPF Programs”Submitted PRR – a terminal tool for managing Pull Requests on GitHub as a story · 60 points
HN discussionThe article is very recent (September 2023 [1]), mentions that "rax is used to return integer values" in the SysV ABI (hence implicitly the 64-bit SysV ABI). Also confirmed in this excerpt: > Note that the top 56 bits in rax are not zeroed – they contain junk. This is fine b/c the compiler will only make callers check the lowest bit of a register for boolean operations. This is why changing the compiler’s “understan…
Comment linking /
on “Truthiness in C”Submitted Application Blackbox as a story · 4 points
HN discussionSubmitted Reading Local Variables with Bpftrace as a story · 3 points
HN discussionSubmitted Errno and libc as a story · 3 points
HN discussionSubmitted Truthiness in C as a story · 3 points
HN discussionSubmitted Libbpf-rs: eBPF for the Rust ecosystem as a story · 3 points
HN discussionSubmitted Big Strings in Bpftrace as a story · 2 points
HN discussionSubmitted Pull Request Review (Prr) as a story · 2 points
HN discussionSubmitted Pull request review: still files as a story · 2 points
HN discussionSubmitted Bpfilter Is Forever as a story · 2 points
HN discussionSubmitted Kernel String Overcopying as a story · 2 points
HN discussionSubmitted Libbpf-rs: eBPF for the Rust ecosystem as a story · 2 points
HN discussionSubmitted /proc/[pid] and the missing threads as a story · 2 points
HN discussionSubmitted Creating a basic Linux kernel development setup as a story · 2 points
HN discussionSubmitted Optimistic concurrency control in Apache Trafficserver as a story · 2 points
HN discussionSubmitted Parameter-efficient fine-tuning in tinygrad as a story · 1 points
HN discussionSubmitted Packet drop reasons (Linux kernel) as a story · 1 points
HN discussionSubmitted Packet Drop Reasons as a story · 1 points
HN discussionSubmitted Bpfilter Is Forever as a story · 1 points
HN discussionSubmitted Sudo and Signal Propagation as a story · 1 points
HN discussionSubmitted BPF and Go Pprof as a story · 1 points
HN discussionSubmitted Vmtest: Run your tests in virtual machines as a story · 1 points
HN discussionSubmitted File capabilities and procfs as a story · 1 points
HN discussionSubmitted Understanding Btrfs Internals as a story · 1 points
HN discussion