Re: [RFC PATCH 0/6] Introduce cluster cpu topology support

[wangyanan (Y)]

Hi Philippe,

On 2021/4/27 17:57, Philippe Mathieu-Daudé wrote:
> Hi Yanan,
>
> On 3/31/21 11:53 AM, Yanan Wang wrote:
> > Hi,
> > This series introduces the cluster cpu topology support, besides now
> > existing sockets, cores, and threads.
> >
> > A cluster means a group of cores that share some resources (e.g. cache)
> > among them under the LLC. For example, ARM64 server chip Kunpeng 920 has
> > 6 or 8 clusters in each NUMA, and each cluster has 4 cores. All clusters
> > share L3 cache data while cores within each cluster share the L2 cache.
> >
> > Also, there are some x86 CPU implementations (e.g. Jacobsville) where L2
> > cache is shared among a cluster of cores instead of being exclusive to
> > one single core. For example, on Jacobsville there are 6 clusters of 4
> > Atom cores, each cluster sharing a separate L2, and 24 cores sharing L3).
> > About this series:
> > Note that, this series was implemented based on [3] and [4]. Although they
> > have not merged into qemu mainline for now, it's still meaning to post this
> > series to express the thoughts first. So a RFC is sent and any comments are
> > welcomed and appreciated.
> At a glance: tests/unit/test-x86-cpuid.c should be adapted to be generic
> (but still supporting target-specific sub-tests) and some aarch64 tests
> added.
>
> Similarly the ARM PPTT tables tested in tests/qtest/bios-tables-test.c.
>
> Otherwise, the overall series looks good and coherent, but it isn't my
> area :)
Thank you for the reminder of the related tests. :)
I will have some work to make them cover the new features introduced
by this series.

Thanks,
Yanan
> Regards,
>
> Phil.
>
> .