Claude Code helps build a Linux kernel performance fix: Linus Torvalds says it was used for the patch series
Linus Torvalds has now turned to Anthropic’s Claude Code for a new Linux kernel patch series, and not for some throwaway cleanup. This one goes after a page-cache bottleneck that’s been around for a long time. In the Linux kernel mailing list post, Torvalds says the tool, working under his direction, produced the eight patches, the test programs, the review work, and even the first draft of the cover letter. The target is a very real slowdown: multiple threads doing tiny reads from the same cached file, which ends up hammering folio reference counts and bouncing a cache line back and forth across CPU cores.
Torvalds gave a concrete example. On a 4-core, 8-thread Intel Core i7-8565U, he said that eight threads issuing 16-byte pread() calls against the same page caused one shared cache line to account for 99.92% of cross-core load through HITMs.
The fix, as Torvalds described it, is to delay page-cache memory reuse until an RCU grace period has passed. That lets readers inside an RCU read-side section copy data into user buffers without first grabbing a folio reference, while still preserving memory safety. In Torvalds’ testing, throughput went from roughly 10 million reads per second to more than 30 million.
If you keep an eye on Linux performance work, this patch series is one to watch.
Torvalds is still drawing a hard line on responsibility. People have to direct the tool, review the output, and understand the code they’re sending in. He also says Linux kernel contributions that use tools like this now need clear disclosure, including tags such as Co-developed-by. If you want to track the series, it’s on the Linux kernel mailing list.
{
"social": {
"email": "",
"facebook": "",
"twitter": "",
"linkedin": ""
},
"ja-JP": "",
"de-DE": "Manuel Bosque schreibt bei Softonic über Software: Desktop-Programme, Produktivitätswerkzeuge und kleine Tools, die ein Problem wirklich lösen. Sein Maßstab ist praktisch — was ein Programm tatsächlich leistet, was es dafür verlangt und für wen es sich lohnt —, deshalb misstraut er Funktionslisten und testet lieber selbst. Er gehört zum Team, das festlegt, wie Software auf der Seite behandelt wird, und arbeitet täglich mit KI-Werkzeugen in der redaktionellen Produktion.",
"en-US": "Manuel Bosque covers software at Softonic: desktop programs, productivity tools and the small utilities that solve one problem well. His approach is practical — what a program actually does, what it asks in return and who it is for — which is why he distrusts feature lists and prefers to test. He is part of the team that decides how software gets covered on the site, and works daily with AI tools applied to editorial production.",
"es-ES": "Manuel Bosque se ocupa de la cobertura de software en Softonic: programas de escritorio, herramientas de productividad y utilidades pequeñas que resuelven bien un solo problema. Su criterio es práctico —qué hace realmente un programa, qué pide a cambio y a quién le sirve—, y por eso desconfía de las listas de funciones y prefiere probar. Forma parte del equipo que decide cómo se cuenta el software en la web y trabaja a diario con herramientas de IA aplicadas a la producción editorial.",
"fr-FR": "Manuel Bosque couvre les logiciels chez Softonic : programmes de bureau, outils de productivité et petits utilitaires qui résolvent bien un seul problème. Son approche est pratique — ce qu'un logiciel fait vraiment, ce qu'il demande en échange et à qui il s'adresse —, d'où sa méfiance envers les listes de fonctionnalités et sa préférence pour l'essai. Il fait partie de l'équipe qui définit la manière de traiter le logiciel sur le site et travaille au quotidien avec des outils d'IA appliqués à la production éditoriale.",
"it-IT": "Manuel Bosque si occupa di software su Softonic: programmi per il desktop, strumenti di produttività e piccole utility che risolvono bene un solo problema. Il suo criterio è pratico — cosa fa davvero un programma, cosa chiede in cambio e a chi serve — e per questo diffida degli elenchi di funzioni e preferisce provare. Fa parte del team che decide come si racconta il software sul sito e lavora ogni giorno con strumenti di IA applicati alla produzione editoriale.",
"nl-NL": "Manuel Bosque schrijft bij Softonic over software: desktopprogramma's, productiviteitstools en kleine hulpprogramma's die één probleem echt oplossen. Zijn maatstaf is praktisch — wat een programma werkelijk doet, wat het daarvoor vraagt en voor wie het nuttig is — en daarom wantrouwt hij functielijstjes en test hij liever zelf. Hij maakt deel uit van het team dat bepaalt hoe software op de site wordt behandeld en werkt dagelijks met AI-tools in de redactionele productie.",
"pl-PL": "Manuel Bosque zajmuje się oprogramowaniem w Softonicu: programami na komputer, narzędziami do pracy i niewielkimi aplikacjami, które dobrze rozwiązują jeden problem. Jego kryterium jest praktyczne — co program naprawdę robi, czego wymaga w zamian i komu się przyda — dlatego nie ufa listom funkcji i woli sprawdzić sam. Należy do zespołu, który decyduje, jak pisać o oprogramowaniu w serwisie, i codziennie korzysta z narzędzi AI w produkcji redakcyjnej.",
"pt-BR": "Manuel Bosque cobre software na Softonic: programas para desktop, ferramentas de produtividade e pequenos utilitários que resolvem bem um problema só. Seu critério é prático — o que um programa realmente faz, o que pede em troca e para quem serve — e por isso desconfia de listas de recursos e prefere testar. Faz parte da equipe que define como o software é abordado no site e trabalha diariamente com ferramentas de IA aplicadas à produção editorial."
}
View all posts by Manuel Bosque
