More hot bytecode! `jctools-core-jdk11` 4.0.6 is now out. This contains `VarHandle` queues generated from `Unsafe` queues to provide similar performance but within JDK APIs. Thanks to github.com/amarziali @datadoghq.com for the huge contribution, and @forked-franz.bsky.social for helping to land!

github.com/netty/netty/... This is only needed for 4.1.x, in 4.2.x we are able to fix this in another way that does not require the usage of sun.misc.Unsafe

The Devoxx Belgium 2025 CFP is now OPEN! ➡️https://dvbe25.cfp.dev This year we’re zooming in on Java 25 & AI Agents🤖 Got insights, hacks, or bold ideas? Share them with the dev community at #Devoxx 🔥

From @forked-franz.bsky.social : These days, lot of @openjdk.org loom fun: github.com/franz1981/Ne... Do you know that VT schedulers are inherited? Which means that if you have your own and clinit some Key OpenJDK class, u risk to make your scheduler to leak into some JDK class (!)

Today I learned that in IBM J9 not all classes are the same: > "A ROM Class roughly corresponds to the contents of a .class file; it is not a complete class because it only references its superclass and implemented interfaces by name." blog.openj9.org/2018/11/08/a... github.com/eclipse-open...

❌ printf debugging ✅ segfault debugging

⏰ Starting soon! Join us for Quarkus Insights Ep. #206 as Andrea Peruffo & Hiram Chirino join us to talk about WebAssembly (WASM) & how it powers a wide range of apps & reveals potential for unique integrations & performance gains, in Java & Quarkus. bit.ly/quarkusinsig...

TIL: since jdk22 you can use the JVM option -XX:LogClassLoadingCauseFor=com.mycompany.MyClass in conjunction with -Xlog:class+load+cause* to find out the stacktrace that triggers the load of the specify class. see github.com/openjdk/jdk/...

Was fighting a "LinkageError: attempted duplicate class definition" for 3 days... took me 2 seconds with that option!

The podcast episodes by @adambien.blog and @forked-franz.bsky.social talking low level Java performance stuff are 🙌🏻🙌🏻 I hope they do more airhacks.fm#episode_343 airhacks.fm#episode_340

Showing kiddo Porco Rosso

A modified version of this: github.com/rigtorp/MPMC...

(We need the queue to be lock-free even though the kernel is single-threaded because we may want to schedule a task from an interrupt handler, and if the interrupt fires during a task schedule that held a lock on the queue, the kernel would deadlock)

The idea is that I have a cooperatively-scheduled single-threaded OS kernel that uses C++20 coroutines as its means of expressing tasks. I want to be able to await on asynchronous tasks, and also manually yield back to the scheduler in the case of long-running computations. Some examples:

CRT support The performance is great and this is very easy to use for younger kids.

If anyone knows of resources for this, I am very much interested, as I am more or less fumbling around. Getting a simple scheduler based on a lock free MPMC queue that works for basic coroutines was pretty straightforward, but as soon as those coroutines nest it becomes very headache-inducing.

Trying to implement an OS-level scheduler for C++20 coroutines that supports symmetric transfer and my brain is melting

Hello you fine Internet folks, Today's article we are deep-diving into the architecture of Zhaoxin's latest CPU series, the KX-7000. We compare the KX-7000 to the KX-6000 along with some older x86 CPUs. Hope y'all enjoy! open.substack.com/pub/chipsand... old.chipsandcheese.com/2025/04/30/z...

I finally got my hard copy of @tartanllama.xyz's Building a Debugger and boy is it a treat! Not only is it a missing guide to DWARF for dummies like me, but it is also a gentle introduction to x64 ASM. Highly recommended! Kudos to @nostarchpress.bsky.social really my fav tech publisher :chefkiss:

github.com/JCTools/JCTo... by @forked-franz.bsky.social need to spend some time at this work 🤯 #jdk24 #jctools

We just integrated a performance improvement to Java String that will provide a ~10x performance boost in some applications where Strings are used as keys and where the associated values are constant foldable. This will make JDK 25 faster. github.com/openjdk/jdk/...

🧩 Are We Enterprise-Ready Yet? By @evacchi.dev & @andreatp.bsky.social @ Wasm I/O 2025 ▶️ Video: youtu.be/UyyVL-dDbCw 🔗 Slides: docs.google.com/presentation... #wasmio25

Hello you fine Internet folks, Today we have an interview with @oxidecomputer.bsky.social's @bcantrill.bsky.social about Oxide and what hardware they are building and the reasons why. Hope y'all enjoy! open.substack.com/pub/chipsand... old.chipsandcheese.com/2025/03/27/a... youtu.be/5-nOIlrUqMM

Rare chance to see me in person in Singapore! March 27 I'll present on an extremely interesting JVM performance topic: www.meetup.com/singadev/eve... Also looking forwards to network and discuss anything related to @quarkus.io , @hibernate.org , @commonhaus.org 😉

Hello you fine Internet folks, Today's article is on Zen 5's frequency behavior when dealing with AVX512 instructions and seeing just how differently Zen 5 behaves to Skylake-X. Hope y'all enjoy! open.substack.com/pub/chipsand... old.chipsandcheese.com/2025/02/28/z...

#EmbarrassmentInChief 🤮

Here is a recent out-of-order RISC V simulator sc-nas.fit.vutbr.cz/riscv-sim/ Paper: arxiv.org/abs/2411.07721

@chipsandcheese.bsky.social hi! Do you know where I can start digging into what happen, step by step, in an OOO arch like the one at i.sstatic.net/PmR2H.png I can find info on stack overflow from Peter Cordes, but never something step of step which try to show happen with some asm, by example 🙏

I’m impressed on how good the Breath of the Wild sound track is. Each time I listen to it I discover new things i.e. this morning I realised Ganon’s tracks are based on an harmonic minor scale and that should be obvious as Ganon is a gerudo himself.

UGH. And *facepalm*. It was indeed wrong process. Not because I mis-identified local service but... because client was connecting to shared test env (because I switched between scripts). So you were right indeed. No activity, no profile.

Now the #JDK's has a `jcmd {pid} System.map` that works and macos! After first Linux, then windows in September. github.com/openjdk/jdk/...

P.S. Chester made a Video so go watch that as well! www.youtube.com/watch?v=SwlK...

Hello you fine Internet folks, Today we look at disabling Zen 4's op cache for fun and giggles as well as seeing just what kind of effects this would have. Hope y'all enjoy! open.substack.com/pub/chipsand... old.chipsandcheese.com/2024/12/10/t...

Hello you fine Internet folks, Today we return to our SC24 coverage with Fujitsu's Monaka CPU which an ARMv9 based CPU with SVE2 that uses 3D stacking and is due in 2027. Hope y'all enjoy! open.substack.com/pub/chipsand... old.chipsandcheese.com/2024/12/13/f... youtube.com/shorts/9w1Tr...

It was really nice to see my work used to reduce latency of complex event recognition queries by an order of magnitude in a paper in ACM, but I was disappointed to find I hadn’t been cited, hopefully this will be fixed. github.com/Josehokec/AC...

Video game characters are not actually real. They don’t bleed, they can’t get their feelings hurt, they can’t be betrayed because they are a collection of pixels and code and words and sound files. The game devs I’m lucky to work with are real people who deserve at least basic human respect.

I am working on something #java #wasm

ubisoft laying off hundreds of people in *december* is just evil honestly

Made some quick prototype with @quarkus.io and the new improved error message in dev is very cool. Here it clearly says: add a missing lib man!

Change Point Detection for performance testing just reached a whole new level. The project behind nyrkio.com and used in companies like Confluence and DataStax just got accepted into the ASF incubator project. Aww yeah!

Hello you fine Internet folks, Today we have an interview with the CEO of NextSilicon, Elad Raz, talking about why are they putting HPC first and what does the Maverick 2 do differently. Hope y'all enjoy! open.substack.com/pub/chipsand... old.chipsandcheese.com/2024/11/28/n... youtu.be/wmLfIcObDQ8

Hello you fine Internet folks, Today we have something new for y'all in the form of a YouTube Short about Ayar Labs and their second generation of co-packaged optics. Hope y'all enjoy! youtube.com/shorts/Kssi8... chipsandcheese.com/p/ayar-labs-... old.chipsandcheese.com/2024/11/25/a...

Hello you fine Internet Folks, Today we are looking at what happens when you push several different generations of AMD's Infinity Fabric to its limits and how it behaves under significant load. Hope y'all enjoy! chipsandcheese.com/p/pushing-am... old.chipsandcheese.com/2024/11/24/p...

Welcome, @forked-franz.bsky.social! I’ve really missed your high quality jvm performance insights since leaving the other site :-)

Some of you may not have noticed @forked-franz.bsky.social is on here now, keep him off the other place by saying hello