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Brice Dutheil @bricedutheil.bsky.social · 2d

JDK Memory corruption on AArch64 Byte code Rewriting, this can lead to impossible branch being taken among other issues.
(via Ismael Juma on Twitter)
bugs.openjdk.org/browse/JDK-8...
#openjdk

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bugs.openjdk.org

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Cliff Click @cliffclick.bsky.social · 2d

youtu.be/wYO4-s8WsnA
Modules, std lib, abi, portable ELF, cffi, build systems, dependencies, project root, xtc modules, as directories, diff in “module” impls, meaning of “import”, foreign modules. Typechecking dead code? Combinatorial explosion build targets

Coffee Compiler Club, 2025_10_10

YouTube video by Cliff Click

youtu.be

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Aleksey Shipilëv @shipilev.bsky.social · 3d

Ever seen a verbose render how a very small GC operation looks like in the context of larger safepoint? Here it is: (I need to blog about things you can see there)

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Johannes Bechberger @mostlynerdless.de · 3d

Learn how to compare objects from JFR recordings in Java and why this is slightly trickier than you might have expected in this week's blog post: mostlynerdless.de/blog/2025/10...

JFR and Equality: A tale of many objects - Mostly nerdless

Learn how to compare objects from JFR recordings in Java and why this is slightly trickier than you might have expected.

mostlynerdless.de

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Brice Dutheil @bricedutheil.bsky.social · 3d

Wow, just noticed that Netty 5 will have the Java 25 baseline !

github.com/netty/netty/...
#netty #java #java25

bump netty5 java version requirement to 25 by derklaro · Pull Request #15676 · netty/netty

Motivation: With the addition of MemorySegment into the JDK the Unsafe and ByteBuffer based Buffer implementations are no longer needed. Due to a bug on jdk versions before 25 the nio buffers creat...

github.com

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Charles Oliver Nutter @headius.bsky.social · 18d

OMG it makes a huge difference. Without even pinning to tier 1 ("dev" mode) we have a new record base startup of 361ms on my M4 MBA. I'm playing with some other tweaks and a longer training run now.

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Charles Oliver Nutter @headius.bsky.social · 19d

New post: JRuby and JDK 25: Startup Time with AOTCache

Let's take a look at JRuby's startup time journey, all the way up to using JDK 25's AOTCache and Project Leyden features coming to a JDK near you soon.

blog.headius.com/2025/09/jrub...

JRuby and JDK 25: Startup Time with AOTCache

JDK 25 is the newest LTS release since JDK 21, and it ships with a gaggle of amazing VM-level features. This post will cover one of the most important improvements for command-line ecosystems like…

blog.headius.com

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Brice Dutheil @bricedutheil.bsky.social · 18d

Today I learned that since #JDK 11, there is now in thread dumps

- cpu=... : the time the thread spent executing on the CPU.
- elapsed=... : the wall clock time passed since the thread was started.

bugs.openjdk.org/browse/JDK-8...

I’m not proud to have missed that 🤦‍♂️

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bugs.openjdk.org

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Brice Dutheil @bricedutheil.bsky.social · 17d

Nice engineering blog post on some query filtering at scale. There are some lessons in there.

They used a "bloofi " multidimensional bloom filters.
axiom.co/blog/buildin...
lemire.me/en/publicati...

Haydex: From Zero to 178,600,000,000 rows a second in 30 days

This is the story of how we turned a failed filter prototype into a production system running at 178.6B rows/sec in 30 days.

axiom.co

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Aleksey Shipilëv @shipilev.bsky.social · 19d

New toy, "residence graphs": tracking the compilation level for top method in the stack. On the left, normal JIT mode: compilers are busy, intp -> T2 -> T3 code is hot; T4 code slowly takes over. On the right, normal AOT+JIT (Leyden) mode: AOT code carries most of it, JIT happens to plug the holes.

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Aleksey Shipilëv @shipilev.bsky.social · 21d

"Method Tracing" in async-profiler: github.com/async-profil...

Method Tracing · async-profiler async-profiler · Discussion #1497

Background Async-profiler is often described as a low-overhead sampling profiler for Java. Sampling means the profiler collects statistical information about program execution by periodically inter...

github.com

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Alexander Reelsen @spinscale.bsky.social · 23d

SIMD Within a Register: How I Doubled Hash Table Lookup Performance

Learned about SWAR the first time in the one-billion row challenge. Nice explanation including benchmarks.

SIMD Within a Register: How I Doubled Hash Table Lookup Performance | MALTSEV.SPACE

It started with a simple thought: four bytes in a hash table bucket look just like an integer. Luckily, this one idea led to a deep dive into bit-twiddling and a 2x performance boost.

maltsev.space

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Cliff Click @cliffclick.bsky.social · 23d

youtu.be/q4mRNu6_lpc
C++ debugging, -Og, safepoints, adr sanitization. kefir (from scratch C compile), SCCP in Simple, graph DSL. Strict aliasing, implicit conversions. Pointer comparison. GPU Kernels DSLs (Triton, Gluon, TLX), Object layout, NUMA. Distributed random forest

Coffee Compiler Club, 2025_09_19

YouTube video by Cliff Click

youtu.be

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Brice Dutheil @bricedutheil.bsky.social · 26d

Nice usage of #zstd for tarball via Kelly Sommers on Twitter.

x.com/vmg/status/1...

Vicent Martí on X: "I love Zstd. It is my default goto for anything compression related: it has a sweet spot between availability (it’s now standardized!! RFC8478), complexity, performance and compression ratio. My favorite thing about it are the skippable frames. Just a killer feature. It’s not https://t.co/7hzG2GzMAx" / X

I love Zstd. It is my default goto for anything compression related: it has a sweet spot between availability (it’s now standardized!! RFC8478), complexity, performance and compression ratio. My favorite thing about it are the skippable frames. Just a killer feature. It’s not https://t.co/7hzG2GzMAx

x.com

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Gunnar Morling @gunnarmorling.dev · 26d

📝 Blogged: "Let's Take a Look at... Lower Java Tail Latencies With ZGC"

As #Java 25 got released earlier this week, I took the ZGC garbage collector for a spin, exploring how it lives up to its promise of sub-millisecond GC pause times.

👉 www.morling.dev/blog/lower-j...

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Johannes Bechberger @mostlynerdless.de · 26d

With Java 25, there is finally a CPU-time profiler in the OpenJDK.

You can read more about this new profiler and some implementation details in my blog series starting with mostlynerdless.de/blog/2025/06... #java25

Java 25's new CPU-Time Profiler (1) - Mostly nerdless

Learn all about Java 25's new CPU-time profiler and why it matters in this weeks blog post from the creator himself.

mostlynerdless.de

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Teiva Harsanyi @teivah.dev · 27d

What Makes System Calls Expensive: A Linux Internals Deep Dive.
blog.codingconfessions.com/p/what-makes...

Another great post by @abhi9u.bsky.social. I learned a lot, including vDSO.

What Makes System Calls Expensive: A Linux Internals Deep Dive

An explanation of how Linux handles system calls on x86-64 and why they show up as expensive operations in performance profiles

blog.codingconfessions.com

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JChateau Unconference @jchateauunconf.bsky.social · 26d

JChateau our Unconference organized in France in the area of the Châteaux of the Loire Valley is open for registration at : www.jchateau.org/registration...

JChateau – Registration

JChateau

www.jchateau.org

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Mark Reinhold @mreinhold.org · 27d

Java 25 / JDK 25: General Availability: mail.openjdk.org/pipermail/jd...

Features: openjdk.org/projects/jdk...

Downloads: jdk.java.net/25/

#Java25 #JDK25 #OpenJDK #Java

Java 25 / JDK 25: General Availability

mail.openjdk.org

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Stephan Janssen @stephanjanssen.be · 27d

Oracle detaches #GraalVM from the Java SE train 👀
• JDK 24 = last with Graal JIT / GraalVM in Java SE
• Native Image discontinued for #Java SE (-> Leyden)
• GraalVM team pivots to non-Java (GraalPy, GraalJS)
👉 Java devs: migrate to C2 JIT & track Leyden AOT work
blogs.oracle.com/java/post/de...

blogs.oracle.com

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Cliff Click @cliffclick.bsky.social · Sep 12

youtu.be/5YIhnjThoK4
Burning Man, boats diving between dust devils. LSP, C backend, debug info, codegen , zydis, ASM. Ryan/quxlang update - literal types, bitwise operators, keywords, functions, containers. LLVM LogicalResult. GCC and LLVM funding, Triton, Cuda, ML , Mojo

Coffee Compiler Club, 2025_09_12

YouTube video by Cliff Click

youtu.be

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Markus Eisele @myfear.com · Sep 11

Let's Take a Look at... JEP 483: Ahead-of-Time Class Loading & Linking! buff.ly/vXDtFq9
#Java #jdk #jep483

Let's Take a Look at... JEP 483: Ahead-of-Time Class Loading & Linking!

In the "Let’s Take a Look at…!" blog series I am exploring interesting projects, developments and technologies in the data and streaming space. This can be KIPs and FLIPs, open-source projects,…

buff.ly

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JChateau Unconference @jchateauunconf.bsky.social · Sep 10

The date have been confirm to 04-08 march 2026, registration will open soon

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JEP Tracker @jeptracker.bsky.social · Sep 9

🎓 JEP 523 moved to candidate
Title: Make G1 the Default Garbage Collector in All Environments
Type: feature
Component: hotspot / gc
See openjdk.org/jeps/523

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Tanel Poder @tanelpoder.com · Sep 9

The xCapture and xtop eBPF tools are now in beta, with a demo dataset!

With a pre-recorded xcapture dataset from my dev server, now you can play with xtop "thread activity sampling" drilldown even on your laptop, without having to run xcapture yourself!

(link in replies :-)

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