Re: [PATCH v3 00/12] arm64: Add HOTPLUG_PARALLEL support for secondary CPUs

From: Shrikanth Hegde

Date: Mon Jun 29 2026 - 00:06:24 EST




On 6/24/26 2:55 PM, Jinjie Ruan wrote:
Support for parallel secondary CPU bringup is already utilized by x86,
MIPS, and RISC-V. This patch brings this capability to the arm64
architecture.

Introduce CONFIG_HOTPLUG_PARALLEL_SMT to avoid primary SMT threads
to boot first constraint.

And add a 'cpu' parameter to update_cpu_boot_status() to allow updating
the boot status at a per-CPU granularity during parallel bringup.

Rework the global `secondary_data` and `__early_cpu_boot_status` accessed
during early boot into per-CPU arrays to allow secondary CPUs to boot
in parallel.


Shouldn't this be called CONFIG_BRINGUP_PARALLEL instead?
Hotplug usually means disable/enable CPU at runtime.