[PATCH v4] powerpc/smp: Use nid as fallback for package_id

[Michael Ellerman]

On Wed, 2020-01-29 at 13:51:21 UTC, Srikar Dronamraju wrote:
> Package_id is to find out all cores that are part of the same chip. On
> PowerNV machines, package_id defaults to chip_id. However ibm,chip_id
> property is not present in device-tree of PowerVM Lpars. Hence lscpu
> output shows one core per socket and multiple cores.
> 
> To overcome this, use nid as the package_id on PowerVM Lpars.
> 
> Before the patch.
> ---------------
> Architecture:        ppc64le
> Byte Order:          Little Endian
> CPU(s):              128
> On-line CPU(s) list: 0-127
> Thread(s) per core:  8
> Core(s) per socket:  1                           <----------------------
> Socket(s):           16                          <----------------------
> NUMA node(s):        2
> Model:               2.2 (pvr 004e 0202)
> Model name:          POWER9 (architected), altivec supported
> Hypervisor vendor:   pHyp
> Virtualization type: para
> L1d cache:           32K
> L1i cache:           32K
> L2 cache:            512K
> L3 cache:            10240K
> NUMA node0 CPU(s):   0-63
> NUMA node1 CPU(s):   64-127
>  #
>  # cat /sys/devices/system/cpu/cpu0/topology/physical_package_id
>  -1
>  #
> 
> After the patch
> ---------------
> Architecture:        ppc64le
> Byte Order:          Little Endian
> CPU(s):              128
> On-line CPU(s) list: 0-127
> Thread(s) per core:  8			<------------------------------
> Core(s) per socket:  8			<------------------------------
> Socket(s):           2
> NUMA node(s):        2
> Model:               2.2 (pvr 004e 0202)
> Model name:          POWER9 (architected), altivec supported
> Hypervisor vendor:   pHyp
> Virtualization type: para
> L1d cache:           32K
> L1i cache:           32K
> L2 cache:            512K
> L3 cache:            10240K
> NUMA node0 CPU(s):   0-63
> NUMA node1 CPU(s):   64-127
>  #
>  # cat /sys/devices/system/cpu/cpu0/topology/physical_package_id
>  0
>  #
> Now lscpu output is more in line with the system configuration.
> 
> Signed-off-by: Srikar Dronamraju <srikar at linux.vnet.ibm.com>
> Cc: linuxppc-dev at lists.ozlabs.org
> Cc: Michael Ellerman <mpe at ellerman.id.au>
> Cc: Vasant Hegde <hegdevasant at linux.vnet.ibm.com>
> Cc: Vaidyanathan Srinivasan <svaidy at linux.vnet.ibm.com>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/a05f0e5be4e81e4977d3f92aaf7688ee0cb7d5db

cheers