From: Yicong Yang <yangyicong@huawei.com>
To: Shrikanth Hegde <sshegde@linux.ibm.com>
Cc: <yangyicong@hisilicon.com>, <linuxppc-dev@lists.ozlabs.org>,
<x86@kernel.org>, <linux-kernel@vger.kernel.org>,
<morten.rasmussen@arm.com>, <msuchanek@suse.de>,
<gregkh@linuxfoundation.org>, <rafael@kernel.org>,
<jonathan.cameron@huawei.com>, <prime.zeng@hisilicon.com>,
<linuxarm@huawei.com>, <xuwei5@huawei.com>,
<guohanjun@huawei.com>, <catalin.marinas@arm.com>,
<will@kernel.org>, <sudeep.holla@arm.com>, <tglx@linutronix.de>,
<peterz@infradead.org>, <mpe@ellerman.id.au>,
<linux-arm-kernel@lists.infradead.org>, <mingo@redhat.com>,
<bp@alien8.de>, <dave.hansen@linux.intel.com>,
<pierre.gondois@arm.com>, <dietmar.eggemann@arm.com>
Subject: Re: [PATCH v10 0/4] Support SMT control on arm64
Date: Thu, 26 Dec 2024 19:50:36 +0800 [thread overview]
Message-ID: <a9e19d83-cfc4-910c-7bca-b2dd17647c5f@huawei.com> (raw)
In-Reply-To: <d0e73e64-cdf7-443b-a8e3-7c1f25533000@linux.ibm.com>
On 2024/12/26 17:23, Shrikanth Hegde wrote:
>
>
> On 12/20/24 13:23, 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
>>
>
> 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.
>>
> .
next prev parent reply other threads:[~2024-12-26 11:52 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-12-20 7:53 [PATCH v10 0/4] Support SMT control on arm64 Yicong Yang
2024-12-20 7:53 ` [PATCH v10 1/4] cpu/SMT: Provide a default topology_is_primary_thread() Yicong Yang
2024-12-20 7:59 ` Yicong Yang
2024-12-23 16:34 ` Jonathan Cameron
2024-12-24 12:15 ` Yicong Yang
2024-12-26 7:18 ` Shrikanth Hegde
2024-12-26 11:36 ` Yicong Yang
2024-12-20 7:53 ` [PATCH v10 2/4] arch_topology: Support SMT control for OF based system Yicong Yang
2024-12-23 16:33 ` Jonathan Cameron
2024-12-24 12:23 ` Yicong Yang
2024-12-20 7:53 ` [PATCH v10 3/4] arm64: topology: Support SMT control on ACPI " Yicong Yang
2024-12-23 16:40 ` Jonathan Cameron
2024-12-24 12:30 ` Yicong Yang
2024-12-20 7:53 ` [PATCH v10 4/4] arm64: Kconfig: Enable HOTPLUG_SMT Yicong Yang
2024-12-23 16:40 ` Jonathan Cameron
2024-12-26 9:23 ` [PATCH v10 0/4] Support SMT control on arm64 Shrikanth Hegde
2024-12-26 11:50 ` Yicong Yang [this message]
2024-12-26 12:28 ` Shrikanth Hegde
2024-12-27 7:16 ` Yicong Yang
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