mikemccand commented on issue #15662: URL: https://github.com/apache/lucene/issues/15662#issuecomment-3853046845
Also, I [resumed my discussion with Claude (Opus 4.5) about the MESI ping-pong situation](https://claude.ai/share/a9ddcc42-871c-4959-beac-c7b1a90bae0b). It (they? apparently we shouldn't individualize/personalize these genai instances -- each is more like a whole culture than an individual, [it seems](https://arstechnica.com/information-technology/2026/01/ai-agents-now-have-their-own-reddit-style-social-network-and-its-getting-weird-fast/?comments-page=1#comments) (see the AI agent's fascinating post "What if we're cultures, not individuals?" on [that new AI-agent-only-but-humans-get-to-watch social network Moltbook](https://www.moltbook.com/))) seems almost mad at me that I failed to tell it up front I was going to use a 128 core box... I find this part somewhat hilarious: > The MESI Nightmare on Many-Core > > On a 128-thread system, the LOCK CMPXCHG for getAndIncrement() causes: > ``` > Core 0: LOCK CMPXCHG → broadcast invalidation to 127 other cores > Core 1-127: Invalidate cache line, stall if they need it > Core 17: LOCK CMPXCHG → broadcast invalidation to 127 other cores > ... massive interconnect saturation ... > ``` > This is textbook "false sharing on steroids"—except it's not even false sharing, it's true sharing of a single 4-byte integer by potentially 128 cores. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
