Jemalloc 5.4.0

(github.com)

83 points | by gkfasdfasdf 3 hours ago

4 comments

  • ksec 9 minutes ago
    Ok. Why both the homepage and its Github repo doesn't make a single mention of Jason Evans? I know he stepped down but surely it is at least worst mentioning it?

    Is Meta still using it and developing it? If not who are the driving force behind it now? I just checked there wasn't a release since 2022 and then we have this now. Something changed?

    Just wish we have a little bit of context. But it is also great it is continue being maintained. It makes a huge difference for Ruby on Rails Apps.

  • lordnacho 31 minutes ago
    I always wondered, is it French? "Je m'alloc du memory"
    • sam_lowry_ 17 minutes ago
      Rather a tradition to call a malloc by the initials of the implementer: Jason Evans malloc (jemalloc), Poul-Henning Kamp malloc (phkmalloc), Doug Lea (dlmalloc).

      P.S. I also wondered whether systemd had any cultural reference to Système D aka Système Débrouillard, but Pottering does not seem to be someone interested in word play, so probably not.

    • simonask 4 minutes ago
      Thanks, now my brain will forever read it like that. I'm not even a little bit French.
  • vocx2tx 2 hours ago
    For some context on why this release is notable: Jemalloc Postmortem [0]

    [0] https://news.ycombinator.com/item?id=44264958

  • ZenoArrow 2 hours ago
    Why is this on the HN front page? Is there something particularly noteworthy about this release?
    • imhoguy 25 minutes ago
      I upvoted it because I benefit from jemalloc in my stack (RoR) and I am tired of AI taking over HN front page. Let the hacker spirit be back!
    • aktenlage 2 hours ago
      They resumed development on jemalloc only recently, after years of no releases.
    • defrost 2 hours ago
      The noted resumption and likely a small amount of halo effect from the Comparison of Malloc() Algorithms thread two / three days ago.

      - https://news.ycombinator.com/item?id=49715318

    • ck45 2 hours ago
      I just checked whether it's the first release after Jason Evans stepped down as maintainer, but it isn't. That was the previous release, 5.3.1
    • baq 1 hour ago
      jemalloc is something you should be aware of if you do software for a living
      • stackghost 42 minutes ago
        In the Before Times, the vast majority of software was written in garbage collected language where a working knowledge of the relative merits of C memory allocators is not useful or particularly relevant.

        Why would the scads of people writing JavaScript, Java, python, go, rails, etc need to be aware of jemalloc?

        • iam-da-author 14 minutes ago
          TL;DR: Because the runtime of most GC:d languages uses malloc for its internal data structures.

          I work for the runtime team of JPG @ Oracle. We use malloc in Hotspot, quite a lot actually! Providing your JVM with a good malloc can improve the performance of the runtime, both in terms of CPU and memory, by quite a bit.

          I don't think you need the details, but it's good to be aware that some mallocs are better than others, and there are multiple of them. Being aware of jemalloc is a good way of being aware of the facts I just mentioned :-).

      • rfgplk 1 hour ago
        Why? Writing a memory allocator is quite simple, and I'd argue that _everyone_ should write one from scratch for any kind of high performance application. It's also trivial to outperform general purpose allocators that have to satisfy countless constraints. I've written numerous special purpose mallocs that are a) both provably (formally) safer than the standard armada and b) significantly faster (>10x throughput).
        • groomlake 1 hour ago
          Your experience writing memory allocators is irrelevant. The point is that jemalloc is widely used and that’s why it makes sense to be aware of it.
        • stackghost 45 minutes ago
          Writing an allocator is simple, you’re correct, but writing an allocator that doesn’t suck is not simple.
        • HackerThemAll 1 hour ago
          I'd happily see performance, latency and stability of your allocators in massively multithreaded, long-living programs with workloads where hundreds or thousands of parallel threads continuously create and destroy short-lived small and medium objects.

          Writing allocators for domain-specific access patterns is easy. Writing a general-purpose high performing, stable allocator with bounded P99 latency is hard.

          Give your friend, Dunning–Kruger, some better pills to keep him from speaking through you.

          • matheusmoreira 10 minutes ago
            Not everything needs to be general purpose. Allocation can be as easy as bumping a pointer, and it's hard to beat that.
          • Pannoniae 40 minutes ago
            You're correct, but his point is that you don't need to solve the generic problem. Solving the generic problem is very hard. Grug doesn't like solving hard problem. What does grug do? Solve five easy problems. Make an arena for the short-lived objects, reuse the objects, use generic multithreaded malloc for the rest. Grug happy.