Linux 7.1 rewrites the high-resolution timer core so the scheduler pays no overhead to use it, and ships Arm 9.6 LSUI support that hardware-accelerates futex operations on v9.6 silicon. Two embedded-relevant changes in one mainline release, both doing work that embedded teams have historically carried as local patches.
The timer rewrite (commit c1fe867b5bf9) removes a longstanding cost: enabling high-resolution scheduling mode previously imposed measurable overhead, which forced teams targeting sub-millisecond control loops to either accept the penalty, enable CONFIG_PREEMPT_RT, or carry an out-of-tree fix. The 7.1 rewrite eliminates the cost upstream. The Arm 9.6 LSUI addition is separate: new ISA instructions let the kernel read and write user-space memory without first disabling the "privileged access never" protection. Linux 7.1 uses them for futex operations, cutting per-futex syscall overhead on Arm v9.6 silicon already shipping in 2026 edge AI SoCs. RISC-V board support expands to Rockchip RV1103B and new Allwinner A523 peripherals, shrinking the driver backport list for teams on those platforms.
Teams carrying a custom kernel for real-time precision on Arm Cortex-A SoCs should test their workload against 7.1 now. If the timer rewrite closes the gap enough that CONFIG_PREEMPT_RT patches are no longer needed, the payoff is a standard LKML build with a shorter maintenance tail. Converting a forked tree with a multi-week merge cadence into a standard upstream pull is one of the few maintenance costs in embedded firmware that disappears without engineering time.