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

Yicong Yang
2025-03-03T14:44:37Z

On 2025/2/28 19:12, Dietmar Eggemann wrote:
> 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:

will fix.

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

Thanks.