答复: [RFC PATCH 0/5] hw/arm/virt: Introduce cpu topology support

[fangying <fangying1@huawei.com>]

-----邮件原件-----
发件人: Andrew Jones [mailto:drjones@redhat.com] 
发送时间: 2021年3月10日 17:21
收件人: fangying <fangying1@huawei.com>
主题: Re: [RFC PATCH 0/5] hw/arm/virt: Introduce cpu topology support


> Hi Ying Fang,
> 
> Do you plan to repost this soon? It'd be great if it got into 6.0.
>
> Thanks,
> drew


Hi Andrew
Thanks for your remind.
Yes, I will repost and update this series soon.
It seems 6.0 will be soft feature frozen at 3.16.
Deadline is close.

On Thu, Feb 25, 2021 at 04:56:22PM +0800, Ying Fang wrote:
> An accurate cpu topology may help improve the cpu scheduler's decision 
> making when dealing with multi-core system. So cpu topology 
> description is helpful to provide guest with the right view. Dario 
> Faggioli's talk in [0] also shows the virtual topology may has impact on sched performace.
> Thus this patch series is posted to introduce cpu topology support for 
> arm platform.
> 
> Both fdt and ACPI are introduced to present the cpu topology. To 
> describe the cpu topology via ACPI, a PPTT table is introduced 
> according to the processor hierarchy node structure. This series is 
> derived from [1], in [1] we are trying to bring both cpu and cache 
> topology support for arm platform, but there is still some issues to 
> solve to support the cache hierarchy. So we split the cpu topology part out and send it seperately.
> The patch series to support cache hierarchy will be send later since 
> Salil Mehta's cpu hotplug feature need the cpu topology enabled first 
> and he is waiting for it to be upstreamed.
> 
> This patch series was initially based on the patches posted by Andrew Jones [2].
> I jumped in on it since some OS vendor cooperative partner are eager for it.
> Thanks for Andrew's contribution.
> 
> After applying this patch series, launch a guest with virt-6.0 and cpu 
> topology configured with sockets:cores:threads = 2:4:2, you will get 
> the bellow messages with the lscpu command.
> 
> -----------------------------------------
> Architecture:                    aarch64
> CPU op-mode(s):                  64-bit
> Byte Order:                      Little Endian
> CPU(s):                          16
> On-line CPU(s) list:             0-15
> Thread(s) per core:              2
> Core(s) per socket:              4
> Socket(s):                       2
> NUMA node(s):                    2
> Vendor ID:                       HiSilicon
> Model:                           0
> Model name:                      Kunpeng-920
> Stepping:                        0x1
> BogoMIPS:                        200.00
> NUMA node0 CPU(s):               0-7
> NUMA node1 CPU(s):               8-15
> 
> [0] 
> https://kvmforum2020.sched.com/event/eE1y/virtual-topology-for-virtual
> -machines-friend-or-foe-dario-faggioli-suse
> [1] 
> https://lists.gnu.org/archive/html/qemu-devel/2020-11/msg02166.html
> [2] 
> https://patchwork.ozlabs.org/project/qemu-devel/cover/20180704124923.3
> 2483-1-drjones@redhat.com
> 
> Ying Fang (5):
>   device_tree: Add qemu_fdt_add_path
>   hw/arm/virt: Add cpu-map to device tree
>   hw/arm/virt-acpi-build: distinguish possible and present cpus
>   hw/acpi/aml-build: add processor hierarchy node structure
>   hw/arm/virt-acpi-build: add PPTT table
> 
>  hw/acpi/aml-build.c          | 40 ++++++++++++++++++++++
>  hw/arm/virt-acpi-build.c     | 64 +++++++++++++++++++++++++++++++++---
>  hw/arm/virt.c                | 40 +++++++++++++++++++++-
>  include/hw/acpi/acpi-defs.h  | 13 ++++++++  
> include/hw/acpi/aml-build.h  |  7 ++++
>  include/hw/arm/virt.h        |  1 +
>  include/sysemu/device_tree.h |  1 +
>  softmmu/device_tree.c        | 45 +++++++++++++++++++++++--
>  8 files changed, 204 insertions(+), 7 deletions(-)
> 
> --
> 2.23.0
>