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

[wangyanan (Y)]

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.

But actually the only conflict with current upstream is in patch#1 about
machine type compat, so I can also send a new version of this series
rebased on the latest upstream with minor update, if the precedence
consideration of the two series is not so necessary as I thought.

[1] 
20210902110330.18036-1-wangyanan55@huawei.com/">https://lore.kernel.org/qemu-devel/20210902110330.18036-1-wangyanan55@huawei.com/

Thanks,
Yanan
.