Re: [PATCH v11 0/4] Support SMT control on arm64

[Dietmar Eggemann <dietmar.eggemann@arm.com>]

On 18/02/2025 15:10, Yicong Yang wrote:
> From: Yicong Yang <yangyicong@hisilicon.com>
> 
> The core CPU control framework supports runtime SMT control which
> is not yet supported on arm64. Besides the general vulnerabilities
> concerns we want this runtime control on our arm64 server for:
> 
> - better single CPU performance in some cases
> - saving overall power consumption
> 
> This patchset implements it in the following aspects:
> 
> - Provides a default topology_is_primary_thread()
> - support retrieve SMT thread number on OF based system
> - support retrieve SMT thread number on ACPI based system
> - select HOTPLUG_SMT for arm64
> 
> Tests has been done on our ACPI based arm64 server and on ACPI/OF
> based QEMU VMs.

[...]

> Yicong Yang (4):
>   cpu/SMT: Provide a default topology_is_primary_thread()
>   arch_topology: Support SMT control for OF based system
>   arm64: topology: Support SMT control on ACPI based system
>   arm64: Kconfig: Enable HOTPLUG_SMT
> 
>  arch/arm64/Kconfig                  |  1 +
>  arch/arm64/kernel/topology.c        | 66 +++++++++++++++++++++++++++++
>  arch/powerpc/include/asm/topology.h |  1 +
>  arch/x86/include/asm/topology.h     |  2 +-
>  drivers/base/arch_topology.c        | 27 ++++++++++++
>  include/linux/topology.h            | 22 ++++++++++
>  6 files changed, 118 insertions(+), 1 deletion(-)

With the review comments on the individual patches [0-3]/4:

Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>