Top all-time · #21603
Arkanis
Personal blog · arkanis.de/weblogprogrammingsystems
Arkanis is a personal blog at arkanis.de about programming and systems. Since 2010, 3 different Hacker News readers have linked it 7 times. No feed was found, so read it on the site itself.
Too few sampled comments (3) to say how often HN recommends it.?
Why HN links it
HN readers link these posts for system call timing measurements, cited for figures such as about 250ns for non-vDSO Linux syscalls and roughly 68ns for vDSO-style calls. Comments use them as data sources.
Summarised by Claude from a sample of 3 HN comments that link here. Each comment is marked recommending, critical or neutral (citing without judging); how this works.
Most-linked posts?
- /weblog/2017-01-05-measurements-of-system-call-performance-and-overhead/2 people · 3 mentions · first linked 2025-09-27
What Hacker News says?
Are you sure they're outliers? Here's someone else with similar results: https://arkanis.de/weblog/2017-01-05-measurements-of-system-... Google also reported similar numbers in 2011, when publicizing their fiber work. I can also get similar numbers (~68ns) on 9front, though a little higher.
Comment linking /weblog/2017-01-05-measurements-of-system-call-performance-and-overhead/
on “Fast UDP I/O for Firefox in Rust”Submitted Experiments with the CELT audio codec as a story · 23 points
HN discussionNo need to guess, it's 10 lines of code. And you can use bpftrace to watch the test program enter the kernel. Using the libc wrapper will use the vdso. Using syscall() will enter the kernel. I haven't measured, but calling the vdso should be closer to 5ns. Someone else did more detailed measurements here: https://arkanis.de/weblog/2017-01-05-measurements-of-system-...
Comment linking /weblog/2017-01-05-measurements-of-system-call-performance-and-overhead/
on “Fast UDP I/O for Firefox in Rust”Submitted Are getters and setters object oriented? as a story · 20 points
HN discussion"Syscalls are slow" is only mostly true. They are slower than not having to cross the userspace <-> OS barrier at all, but they're not "slow" like cross-ocean network calls can be. For example, non-VDSO syscalls in linux are about 250 nanoseconds (see for example https://arkanis.de/weblog/2017-01-05-measurements-of-system-... ), VDSO syscalls are roughly 10x faster. Slower than userspace function calls for sure, but…
Comment linking /weblog/2017-01-05-measurements-of-system-call-performance-and-overhead/
on “Show HN: Honker – Postgres NOTIFY/LISTEN Semantics for SQLite”Submitted Printing the LLVM Language Reference Manual as a story · 2 points
HN discussionSubmitted Fast line iteration in PHP as a story · 1 points
HN discussion