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authorAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>2023-04-04 09:44:33 +0530
committerMichael Ellerman <mpe@ellerman.id.au>2023-04-04 22:08:35 +1000
commitb277fc793daf258877b4c0744b52f69d6e6ba22e (patch)
tree12988ab42917ffc8c65584c678dc9b9cbeebf946 /arch/powerpc/mm/numa.c
parenteca9f6e6f83b6725b84e1c76fdde19b003cff0eb (diff)
downloadlinux-b277fc793daf258877b4c0744b52f69d6e6ba22e.tar.gz
powerpc/papr_scm: Update the NUMA distance table for the target node
Platform device helper routines won't update the NUMA distance table while creating a platform device, even if the device is present on a NUMA node that doesn't have memory or CPU. This is especially true for pmem devices. If the target node of the pmem device is not online, we find the nearest online node to the device and associate the pmem device with that online node. To find the nearest online node, we should have the numa distance table updated correctly. Update the distance information during the device probe. For a papr scm device on NUMA node 3 distance_lookup_table value for distance_ref_points_depth = 2 before and after fix is below: Before fix: node 3 distance depth 0 - 0 node 3 distance depth 1 - 0 node 4 distance depth 0 - 4 node 4 distance depth 1 - 2 node 5 distance depth 0 - 5 node 5 distance depth 1 - 1 After fix node 3 distance depth 0 - 3 node 3 distance depth 1 - 1 node 4 distance depth 0 - 4 node 4 distance depth 1 - 2 node 5 distance depth 0 - 5 node 5 distance depth 1 - 1 Without the fix, the nearest numa node to the pmem device (NUMA node 3) will be picked as 4. After the fix, we get the correct numa node which is 5. Fixes: da1115fdbd6e ("powerpc/nvdimm: Pick nearby online node if the device node is not online") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230404041433.1781804-1-aneesh.kumar@linux.ibm.com
Diffstat (limited to 'arch/powerpc/mm/numa.c')
-rw-r--r--arch/powerpc/mm/numa.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index b44ce71917d75..16cfe56be05bb 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -366,6 +366,7 @@ void update_numa_distance(struct device_node *node)
WARN(numa_distance_table[nid][nid] == -1,
"NUMA distance details for node %d not provided\n", nid);
}
+EXPORT_SYMBOL_GPL(update_numa_distance);
/*
* ibm,numa-lookup-index-table= {N, domainid1, domainid2, ..... domainidN}