Re: [PATCH v6 0/5] hw/arm/virt: Introduce cpu topology support

From: "wangyanan (Y)" <wangyanan55@huawei.com>
To: Andrew Jones <drjones@redhat.com>
Cc: Peter Maydell <peter.maydell@linaro.org>,
	Salil Mehta <salil.mehta@huawei.com>,
	"Michael S . Tsirkin" <mst@redhat.com>,
	QEMU Developers <qemu-devel@nongnu.org>,
	Shannon Zhao <shannon.zhaosl@gmail.com>,
	qemu-arm <qemu-arm@nongnu.org>,
	Alistair Francis <alistair.francis@wdc.com>,
	wanghaibin.wang@huawei.com, Igor Mammedov <imammedo@redhat.com>,
	David Gibson <david@gibson.dropbear.id.au>
Subject: Re: [PATCH v6 0/5] hw/arm/virt: Introduce cpu topology support
Date: Tue, 7 Sep 2021 17:12:35 +0800	[thread overview]
Message-ID: <7bed1b6f-562f-8b43-b63b-5e2530170523@huawei.com> (raw)
In-Reply-To: <20210906161523.4kc5l3usbw6l2s6r@gator.home>


On 2021/9/7 0:15, Andrew Jones wrote:
> On Fri, Sep 03, 2021 at 03:38:13PM +0800, wangyanan (Y) wrote:
>> On 2021/9/3 15:25, Peter Maydell wrote:
>>> On Fri, 3 Sept 2021 at 08:05, wangyanan (Y) <wangyanan55@huawei.com> wrote:
>>>> On 2021/9/2 23:56, Peter Maydell wrote:
>>>>> On Tue, 24 Aug 2021 at 13:20, Yanan Wang <wangyanan55@huawei.com> wrote:
>>>>>> This new version is based on patch series [1] which introduces some
>>>>>> fix and improvement for smp parsing.
>>>>>>
>>>>>> Description:
>>>>>> Once the view of an accurate virtual cpu topology is provided to guest,
>>>>>> with a well-designed vCPU pinning to the pCPU we may get a huge benefit,
>>>>>> e.g., the scheduling performance improvement. See Dario Faggioli's
>>>>>> research and the related performance tests in [2] for reference.
>>>>>>
>>>>>> This patch series introduces cpu topology support for ARM platform.
>>>>>> Both cpu-map in DT and ACPI PPTT table are introduced to store the
>>>>>> topology information. And we only describe the topology information
>>>>>> to 6.2 and newer virt machines, considering compatibility.
>>>>>>
>>>>>> patches not yet reviewed: #1 and #3.
>>>>>>
>>>>>> [1] https://lore.kernel.org/qemu-devel/20210823122804.7692-1-wangyanan55@huawei.com/
>>>>>> [2] https://kvmforum2020.sched.com/event/eE1y/virtual-topology-for-virtual-machines
>>>>>> -friend-or-foe-dario-faggioli-suse
>>>>> Hi; this series doesn't apply to current head-of-git. Is it
>>>>> intended to be based on some other series ?
>>>>>
>>>> Yes, it was based on the -smp parsing changes in [1] which hasn't been
>>>> picked yet. Given that [1] somehow affects the topology parsing results
>>>> which we will describe to guest, I think it may be better that [1] can be
>>>> merged first and then this series follows.
>>> OK. I'll ignore this for now; please resend once that other series
>>> has been accepted.
>> Got it.
> Also, you'll likely want to rebase on Igor's acpi refactor series[*]
>
> [*] https://www.mail-archive.com/qemu-devel@nongnu.org/msg822151.html
>
Ok, sure. I can wait for a while and will rebase the ACPI changes on Igor's
series for next version.

Thanks,
Yanan