{"id":213410,"date":"2026-02-14T06:47:00","date_gmt":"2026-02-14T11:47:00","guid":{"rendered":"https:\/\/news-you-need.com\/index.php\/2026\/02\/14\/linux-7-0-wires-up-arms-64-byte-single-copy-atomic-instructions-ls64-ls64v\/"},"modified":"2026-02-14T09:20:07","modified_gmt":"2026-02-14T14:20:07","slug":"linux-7-0-wires-up-arms-64-byte-single-copy-atomic-instructions-ls64-ls64v","status":"publish","type":"post","link":"https:\/\/news-you-need.com\/index.php\/2026\/02\/14\/linux-7-0-wires-up-arms-64-byte-single-copy-atomic-instructions-ls64-ls64v\/","title":{"rendered":"Linux 7.0 Wires Up Arm’s 64-byte Single-Copy Atomic Instructions LS64\/LS64V"},"content":{"rendered":"

Linux 7.0 Wires Up Arm’s 64-byte Single-Copy Atomic Instructions LS64\/LS64V<\/a><\/p>\n

https:\/\/www.phoronix.com\/news\/ARM64-Linux-7.0<\/a><\/p>\n

Publish Date: 2026-02-14 06:47:00<\/a><\/p>\n

Source Domain: www.phoronix.com<\/a><\/p>\n

Beyond all of the exciting Intel\/AMD x86_64 changes and improvements to enjoy with the upcoming Linux 7.0, there is one notable ARM64 feature addition this kernel cycle.<\/p>\n

The main feature for ARM64 on Linux 7.0 is now supporting 64-byte single-copy atomic instructions (LS64\/LS64V). Armv8.7 introduced single-copy atomic 64-byte load and store instructions. With Linux 7.0 those new instructions are wired up, they are now exposed to user-space via \/proc\/cpuinfo and hardware capabilities. The patch series noted:
\n<\/p>\n

“Armv8.7 introduces single-copy atomic 64-byte loads and stores instructions and its variants named under FEAT_{LS64, LS64_V}.
\n
…
\n
A real scenario for this feature is that the userspace driver can make use of this to implement direct WQE (workqueue entry) – a mechanism to fill WQE directly into the hardware.”
\n
This accelerated, atomic movement of 64-byte blocks should help for helping ARM in more high performance Linux scenarios. The patches also take care of exposing LS64_V to Linux KVM guests.<\/p>\n

\"AmpereOne<\/p>\n

With this pull, ARM64 also now has reduced Memory Tagging Extension (MTE) overhead when executing in the kernel on AmpereOne processors. That patch explains:
\n
“We measured severe performance overhead (25-50%) when enabling userspace MTE and running memcached on an AmpereOne machine.
\n
We identified excessive tag checking taking place in the kernel.
\n
…
\n
For workloads with MTE enabled, we measured the series giving a 2% improvement for “perf bench futex hash” at 95% confidence.<\/p>\n

Also, we used the Phoronix Test Suite pts\/memcached benchmark with a get-heavy workload (1:10 Set:Get ratio) which is where the slowdown appears most clearly. The slowdown worsens with increased core count, levelling out above 32 cores.”<\/p>\n

With the ARM64 updates for Linux 7.0, Spectre-BHB meanwhile is worked around on HiSilicon TSV110 processors.<\/p>\n

All of the ARM64 updates for Linux 7.0 can be found via this pull request that is already merged to Linux 7.0 Git.<\/p>\n

Source<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Linux 7.0 Wires Up Arm’s 64-byte Single-Copy Atomic Instructions LS64\/LS64V https:\/\/www.phoronix.com\/news\/ARM64-Linux-7.0 Publish Date: 2026-02-14 06:47:00…<\/p>\n","protected":false},"author":1,"featured_media":213411,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"fifu_image_url":"https:\/\/www.phoronix.net\/image.php?id=2026&image=ampereone_bios","fifu_image_alt":"","footnotes":""},"categories":[48],"tags":[71],"class_list":["post-213410","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-linux","tag-linux"],"_links":{"self":[{"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/posts\/213410"}],"collection":[{"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/comments?post=213410"}],"version-history":[{"count":1,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/posts\/213410\/revisions"}],"predecessor-version":[{"id":213412,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/posts\/213410\/revisions\/213412"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/media\/213411"}],"wp:attachment":[{"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/media?parent=213410"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/categories?post=213410"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/tags?post=213410"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}