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authorNikunj A Dadhania <nikunj@linux.vnet.ibm.com>2015-07-02 11:09:01 +0530
committerMichael Ellerman <mpe@ellerman.id.au>2015-08-18 19:34:41 +1000
commit1d805440a364b4a68562e70119d8f94456698e55 (patch)
treede592ddd17f3d4849aeb6576f9052f101a54d130 /arch/powerpc
parent53522982fc3c254bb4444c336cb005c8636930c8 (diff)
downloadlinux-1d805440a364b4a68562e70119d8f94456698e55.tar.bz2
powerpc/numa: initialize distance lookup table from drconf path
In some situations, a NUMA guest that supports ibm,dynamic-memory-reconfiguration node will end up having flat NUMA distances between nodes. This is because of two problems in the current code. 1) Different representations of associativity lists. There is an assumption about the associativity list in initialize_distance_lookup_table(). Associativity list has two forms: a) [cpu,memory]@x/ibm,associativity has following format: <N> <N integers> b) ibm,dynamic-reconfiguration-memory/ibm,associativity-lookup-arrays <M> <N> <M associativity lists each having N integers> M = the number of associativity lists N = the number of entries per associativity list Fix initialize_distance_lookup_table() so that it does not assume "case a". And update the caller to skip the length field before sending the associativity list. 2) Distance table not getting updated from drconf path. Node distance table will not get initialized in certain cases as ibm,dynamic-reconfiguration-memory path does not initialize the lookup table. Call initialize_distance_lookup_table() from drconf path with appropriate associativity list. Reported-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com> Acked-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/mm/numa.c16
1 files changed, 13 insertions, 3 deletions
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 5e80621d9324..8b9502adaf79 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -225,7 +225,7 @@ static void initialize_distance_lookup_table(int nid,
for (i = 0; i < distance_ref_points_depth; i++) {
const __be32 *entry;
- entry = &associativity[be32_to_cpu(distance_ref_points[i])];
+ entry = &associativity[be32_to_cpu(distance_ref_points[i]) - 1];
distance_lookup_table[nid][i] = of_read_number(entry, 1);
}
}
@@ -248,8 +248,12 @@ static int associativity_to_nid(const __be32 *associativity)
nid = -1;
if (nid > 0 &&
- of_read_number(associativity, 1) >= distance_ref_points_depth)
- initialize_distance_lookup_table(nid, associativity);
+ of_read_number(associativity, 1) >= distance_ref_points_depth) {
+ /*
+ * Skip the length field and send start of associativity array
+ */
+ initialize_distance_lookup_table(nid, associativity + 1);
+ }
out:
return nid;
@@ -507,6 +511,12 @@ static int of_drconf_to_nid_single(struct of_drconf_cell *drmem,
if (nid == 0xffff || nid >= MAX_NUMNODES)
nid = default_nid;
+
+ if (nid > 0) {
+ index = drmem->aa_index * aa->array_sz;
+ initialize_distance_lookup_table(nid,
+ &aa->arrays[index]);
+ }
}
return nid;