--- title: RISC-V Has A Nice Portable Performance Optimization With... description: Linux 7.4 makes a RISC-V user-copy optimization portable across kernel builds. The feature, merged in Linux 7.3 by Tenstorrent, skips software aligning on... canonical: https://daily.dev/posts/risc-v-has-a-nice-portable-performance-optimization-with-linux-7-4-9prqywv5v twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: RISC-V Has A Nice Portable Performance Optimization With Linux 7.4 | daily.dev og:description: Linux 7.4 makes a RISC-V user-copy optimization portable across kernel builds. The feature, merged in Linux 7.3 by Tenstorrent, skips software aligning on... og:url: https://daily.dev/posts/risc-v-has-a-nice-portable-performance-optimization-with-linux-7-4-9prqywv5v og:image: https://api.daily.dev/og/posts/9PrQYWV5v.png og:image:alt: RISC-V Has A Nice Portable Performance Optimization With Linux 7.4 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. # RISC-V Has A Nice Portable Performance Optimization With Linux 7.4 **[Phoronix](https://daily.dev/sources/phoronix)** · 2 min read · 2 upvotes · 0 comments ## Summary Linux 7.4 makes a RISC-V user-copy optimization portable across kernel builds. The feature, merged in Linux 7.3 by Tenstorrent, skips software aligning on hardware with fast misaligned memory copies, giving up to an 11% bandwidth improvement. In 7.3 it had to be compiled in, so it couldn't be used in generic or distribution kernels built for mixed hardware. Linux 7.4 moves the "HAVE_EFFICIENT_UNALIGNED_ACCESS" check to run-time detection instead. The same RISC-V pull request also adds crash hot-plug support, optimized page table code paths, a context-switching optimization, the "B" ISA extension in hwcap/hwprobe, and Zic64b extension reporting. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What changed for RISC-V unaligned memory access support in Linux 7.4? Linux 7.4 moves the skipping of software aligning for RISC-V hardware, via HAVE_EFFICIENT_UNALIGNED_ACCESS, from a compile-time option to a run-time check. Previously, introduced in Linux 7.3 by Tenstorrent, this optimization had to be compiled in, making it unusable in generic or distribution kernels that run on mixed RISC-V hardware. The run-time detection lets any kernel build benefit when fast unaligned access is present, with benchmarks showing up to an 11% bandwidth improvement. _Kernel engineers tracking RISC-V performance work can follow optimization details like this on daily.dev._ ### What other RISC-V features were added in the Linux 7.4 kernel pull request? The same RISC-V pull request for Linux 7.4 adds crash hot-plug support, optimized code paths for some page table functions, an optimization during context switching, the 'B' RISC-V ISA extension added to hwcap and hwprobe reporting, and support for reporting the RISC-V Zic64b ISA extension. _Developers building for RISC-V can keep up with each kernel's extension support on daily.dev._ ## Similar posts on daily.dev - [Linux 6.19 For RISC-V Brings Parallel CPU Hotplugging, Zalasr Ratified ISA Support](https://daily.dev/posts/linux-6-19-for-risc-v-brings-parallel-cpu-hotplugging-zalasr-ratified-isa-support-u8kpkpcan) · Phoronix · 0 upvotes · 0 comments - [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 - [Linux 7.2 RISC-V Reduces Kernel Startup Overhead, Eswin SoC Support By Default](https://daily.dev/posts/linux-7-2-risc-v-reduces-kernel-startup-overhead-eswin-soc-support-by-default-9p7w6o61h) · Phoronix · 0 upvotes · 0 comments - [RISC-V is sloooow – Marcin Juszkiewicz](https://daily.dev/posts/risc-v-is-sloooow-marcin-juszkiewicz-f19ouew8p) · Hacker News · 1 upvotes · 0 comments --- Tags: [#linux](https://daily.dev/tags/linux), [#performance](https://daily.dev/tags/performance) [View this post on daily.dev](https://daily.dev/posts/risc-v-has-a-nice-portable-performance-optimization-with-linux-7-4-9prqywv5v) ```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":"RISC-V Has A Nice Portable Performance Optimization With Linux 7.4","url":"https://daily.dev/posts/risc-v-has-a-nice-portable-performance-optimization-with-linux-7-4-9prqywv5v","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/risc-v-has-a-nice-portable-performance-optimization-with-linux-7-4-9prqywv5v"},"datePublished":"2026-10-30T00:38:59.669Z","dateModified":"2026-10-30T00:39:36.570Z","description":"Linux 7.4 makes a RISC-V user-copy optimization portable across kernel builds. 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