--- title: Kernel 6.6: Long-awaited features and enhanced hardware... description: Linux Kernel 6.6 introduces several significant changes: the CFS CPU scheduler is replaced by the EEVDF (Earliest Eligible Virtual Deadline First) scheduler,... canonical: https://daily.dev/posts/kernel-6-6-long-awaited-features-and-enhanced-hardware-support-oddsn2x4j twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Kernel 6.6: Long-awaited features and enhanced hardware support | daily.dev og:description: Linux Kernel 6.6 introduces several significant changes: the CFS CPU scheduler is replaced by the EEVDF (Earliest Eligible Virtual Deadline First) scheduler,... og:url: https://daily.dev/posts/kernel-6-6-long-awaited-features-and-enhanced-hardware-support-oddsn2x4j og:image: https://api.daily.dev/og/posts/ODDSn2x4J.png og:image:alt: Kernel 6.6: Long-awaited features and enhanced hardware support og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Kernel 6.6: Long-awaited features and enhanced hardware support **[Collabora Blog](https://daily.dev/sources/collabora)** · 6 min read · 0 upvotes · 0 comments ## Summary Linux Kernel 6.6 introduces several significant changes: the CFS CPU scheduler is replaced by the EEVDF (Earliest Eligible Virtual Deadline First) scheduler, offering improved fairness with fewer tuning knobs. Intel's x86 shadow stack support is finally merged after being rejected in 6.4. RISC-V gains Kernel Control Flow Integrity and user-space performance counter access. Security improvements include kmalloc() randomization to defend against heap spraying. Filesystem additions include fs-verity in overlayfs, NFSv4 write delegations, and the new fchmodat2() syscall. Hardware support expands significantly for MediaTek (eDP on Chromebooks including MT8195), Qualcomm (QSMMUv2/QSMMU-500 IOMMUs on MSM8956/MSM8976), and Rockchip (PCIe, USB2, SATA for RK3588). Collabora's team contributed patches across MediaTek, Rockchip, AMD, and DRM subsystems, including converting the last upstream driver from the legacy videobuf framework to videobuf2. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What replaced the CFS scheduler in Linux kernel 6.6 and how is it different? The CFS scheduler was replaced by EEVDF (Earliest Eligible Virtual Deadline First) in Linux 6.6. Unlike CFS, which uses a single weight parameter, EEVDF uses two parameters: relative deadline and weight. It has a better-defined scheduling policy, removes many CFS heuristics, and results in fewer tuning knobs. Rare performance regressions are expected with some adversarial workloads, and mitigation efforts are ongoing. _Kernel developers tracking scheduler changes and regressions follow developments like this on daily.dev._ ### Was Intel x86 shadow stack support merged into the Linux kernel and when? Intel x86 shadow stack support was merged in Linux kernel 6.6. It had previously been rejected for 6.4 and required cleanup and rework before being accepted. Shadow stack is a hardware security feature that helps protect against return-oriented programming attacks by maintaining a separate stack for return addresses. _Developers shipping security-sensitive Linux systems can track kernel security merges like this on daily.dev._ ### What Rockchip RK3588 features were enabled in Linux kernel 6.6? Linux 6.6 enabled PCIe, USB2, and SATA for RK3588 at the SoC level. Device tree updates added SATA and USB2 support for the RK3588 evaluation board, USB2 for Radxa ROCK 5B, and USB2, fan, ADC, I2C EEPROM, analog audio, status LED, PMIC, and regulators for Radxa ROCK 5A. PCIe support in board device trees missed the cutoff and will arrive in 6.7. _Embedded developers working with RK3588 boards track upstream enablement milestones on daily.dev._ ## Similar posts on daily.dev - [Main changes, Arm, RISC-V, and MIPS architectures](https://daily.dev/posts/main-changes-arm-risc-v-and-mips-architectures-eds3j61xx) · CNX Software · 0 upvotes · 0 comments --- Tags: [#linux](https://daily.dev/tags/linux) [View this post on daily.dev](https://daily.dev/posts/kernel-6-6-long-awaited-features-and-enhanced-hardware-support-oddsn2x4j) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Kernel 6.6: Long-awaited features and enhanced hardware support","url":"https://daily.dev/posts/kernel-6-6-long-awaited-features-and-enhanced-hardware-support-oddsn2x4j","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/kernel-6-6-long-awaited-features-and-enhanced-hardware-support-oddsn2x4j"},"datePublished":"2026-08-11T08:56:14.627Z","dateModified":"2026-08-11T09:30:59.828Z","description":"Linux Kernel 6.6 introduces several significant changes: the CFS CPU scheduler is replaced by the EEVDF (Earliest Eligible Virtual Deadline First) scheduler,...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/c9f480805b9d696db246cd396fa0f3e2?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/c9f480805b9d696db246cd396fa0f3e2?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Collabora Blog","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Collabora Blog","logo":"https://media.daily.dev/image/upload/s--ZGZ0FjqS--/f_auto,q_auto/v1786438306/logos/collabora?_a=BAMAMicg0","url":"https://daily.dev/sources/collabora"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/kernel-6-6-long-awaited-features-and-enhanced-hardware-support-oddsn2x4j","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"linux","timeRequired":"PT6M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Collabora Blog","item":"https://daily.dev/sources/collabora"},{"@type":"ListItem","position":3,"name":"Kernel 6.6: Long-awaited features and enhanced hardware support"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/kernel-6-6-long-awaited-features-and-enhanced-hardware-support-oddsn2x4j#faq","mainEntity":[{"@type":"Question","name":"What replaced the CFS scheduler in Linux kernel 6.6 and how is it different?","acceptedAnswer":{"@type":"Answer","text":"The CFS scheduler was replaced by EEVDF (Earliest Eligible Virtual Deadline First) in Linux 6.6. Unlike CFS, which uses a single weight parameter, EEVDF uses two parameters: relative deadline and weight. It has a better-defined scheduling policy, removes many CFS heuristics, and results in fewer tuning knobs. Rare performance regressions are expected with some adversarial workloads, and mitigation efforts are ongoing. Kernel developers tracking scheduler changes and regressions follow developments like this on daily.dev."}},{"@type":"Question","name":"Was Intel x86 shadow stack support merged into the Linux kernel and when?","acceptedAnswer":{"@type":"Answer","text":"Intel x86 shadow stack support was merged in Linux kernel 6.6. It had previously been rejected for 6.4 and required cleanup and rework before being accepted. Shadow stack is a hardware security feature that helps protect against return-oriented programming attacks by maintaining a separate stack for return addresses. 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