On 2024/12/26 17:23, Shrikanth Hegde wrote: > > > On 12/20/24 13:23, Yicong Yang wrote: >> From: Yicong Yang <yangyic...@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 >> > > EAS is disabled when SMT is present. > I am curious to know how power saving happens here.
EAS shouldn't work on non-asymmetic systems, so it's not the case here. System wide power consumption comes down from the CPU offlining here. Thanks. > >> 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. >> > .
