Form2 associativity adds a much more flexible NUMA topology layout
than what is provided by Form1. This also allows PAPR SCM device
to use better associativity when using the device as DAX KMEM
device. More details can be found in patch 7.
$ ndctl list -N -v
[
{
"dev":"namespace0.0",
"mode":"devdax",
"map":"dev",
"size":1071644672,
"uuid":"37dea198-ddb5-4e42-915a-99a915e24188",
"raw_uuid":"148deeaa-4a2f-41d1-8d74-fd9a942d26ba",
"daxregion":{
"id":0,
"size":1071644672,
"devices":[
{
"chardev":"dax0.0",
"size":1071644672,
"target_node":4,
"mode":"devdax"
}
]
},
"align":2097152,
"numa_node":1
}
]
$ numactl -H
...
node distances:
node 0 1 2 3
0: 10 11 222 33
1: 44 10 55 66
2: 77 88 10 99
3: 101 121 132 10
$
After DAX KMEM
# numactl -H
available: 5 nodes (0-4)
...
node distances:
node 0 1 2 3 4
0: 10 11 22 33 255
1: 44 10 55 66 255
2: 77 88 10 99 255
3: 101 121 132 10 255
4: 255 255 255 255 10
#
The above output is with a Qemu command line
-numa node,nodeid=4 \
-numa dist,src=0,dst=1,val=11 -numa dist,src=0,dst=2,val=22 -numa
dist,src=0,dst=3,val=33 -numa dist,src=0,dst=4,val=255 \
-numa dist,src=1,dst=0,val=44 -numa dist,src=1,dst=2,val=55 -numa
dist,src=1,dst=3,val=66 -numa dist,src=1,dst=4,val=255 \
-numa dist,src=2,dst=0,val=77 -numa dist,src=2,dst=1,val=88 -numa
dist,src=2,dst=3,val=99 -numa dist,src=2,dst=4,val=255 \
-numa dist,src=3,dst=0,val=101 -numa dist,src=3,dst=1,val=121 -numa
dist,src=3,dst=2,val=132 -numa dist,src=3,dst=4,val=255 \
-numa dist,src=4,dst=0,val=255 -numa dist,src=4,dst=1,val=255 -numa
dist,src=4,dst=2,val=255 -numa dist,src=4,dst=3,val=255 \
-object
memory-backend-file,id=memnvdimm1,prealloc=yes,mem-path=$PMEM_DISK,share=yes,size=${PMEM_SIZE}
\
-device
nvdimm,label-size=128K,memdev=memnvdimm1,id=nvdimm1,slot=4,uuid=72511b67-0b3b-42fd-8d1d-5be3cae8bcaa,node=4,device-node=1
Qemu changes can be found at
https://lore.kernel.org/qemu-devel/20210616011944.2996399-1-danielhb...@gmail.com/
Changes from v1:
* Update FORM2 documentation.
* rename max_domain_index to max_associativity_domain_index
Aneesh Kumar K.V (8):
powerpc/pseries: rename min_common_depth to primary_domain_index
powerpc/pseries: rename distance_ref_points_depth to
max_associativity_domain_index
powerpc/pseries: Rename TYPE1_AFFINITY to FORM1_AFFINITY
powerpc/pseries: Consolidate DLPAR NUMA distance update
powerpc/pseries: Consolidate NUMA distance update during boot
powerpc/pseries: Add a helper for form1 cpu distance
powerpc/pseries: Add support for FORM2 associativity
powerpc/papr_scm: Use FORM2 associativity details
Documentation/powerpc/associativity.rst | 177 +++++++
arch/powerpc/include/asm/firmware.h | 7 +-
arch/powerpc/include/asm/prom.h | 3 +-
arch/powerpc/kernel/prom_init.c | 3 +-
arch/powerpc/mm/numa.c | 436 ++++++++++++++----
arch/powerpc/platforms/pseries/firmware.c | 3 +-
arch/powerpc/platforms/pseries/hotplug-cpu.c | 2 +
.../platforms/pseries/hotplug-memory.c | 2 +
arch/powerpc/platforms/pseries/papr_scm.c | 26 +-
arch/powerpc/platforms/pseries/pseries.h | 2 +
10 files changed, 560 insertions(+), 101 deletions(-)
create mode 100644 Documentation/powerpc/associativity.rst
--
2.31.1
