Hacking tips for Linux perf porcelain

Per Vognsen sent me a link to Maziarz et al’s Hashing Modulo Alpha-Equivalence because its Lemma 6.6 claims to solve a thorny problem we have both encountered several times. Essentially, the lemma says that computing the natural recursive combination of hash values over \(2^b\) bits for two distinct trees (ADT instances) \(a\) and \(b\) yields a...

It looks like internauts are having another go at the “UUID as primary key” debate, where the fundamental problem is the tension between nicely structured primary keys that tend to improve spatial locality in the storage engine, and unique but otherwise opaque identifiers that avoid running into Hyrum’s law when communicating with external...

Originally posted on the Backtrace I/O tech blog. All long-lived programs are either implemented in dynamic languages,1 or eventually Greenspun themselves into subverting static programming languages to create a dynamic system (e.g., Unix process trees). The latter approach isn’t a bad idea, but it’s easy to introduce more flexibility than...

Originally posted on the Backtrace I/O tech blog. Slitter is Backtrace’s deliberately middle-of-the-road thread-caching slab allocator, with explicit allocation class tags (rather than derived from the object’s size class). It’s mostly written in Rust, and we use it in our C backend server. Slitter’s design is about as standard as it gets: we...