From: Jianguo Wu <wujian...@huawei.com>
Hi all,
When doing memory-hot-plug, We found node distance is wrong after
offline
a node in IA64 platform. For example system has 4 nodes:
node distances:
node 0 1 2 3
0: 10 21 21 32
1: 21 10 32 21
2: 21 32 10 21
3: 32 21 21 10
linux-drf:/sys/devices/system/node/node0 # cat distance
10 21 21 32
linux-drf:/sys/devices/system/node/node1 # cat distance
21 10 32 21
After offline node2:
linux-drf:/sys/devices/system/node/node0 # cat distance
10 21 32
linux-drf:/sys/devices/system/node/node1 # cat distance
32 21 32 --------->expected value is: 21 10 21
In arch IA, we have following definition:
extern u8 numa_slit[MAX_NUMNODES * MAX_NUMNODES];
#define node_distance(from,to) (numa_slit[(from) * num_online_nodes() + (to)])
node distance is setup as following:
acpi_numa_arch_fixup()
{
...
memset(numa_slit, -1, sizeof(numa_slit));
for (i = 0; i < slit_table->locality_count; i++) {
if (!pxm_bit_test(i))
continue;
node_from = pxm_to_node(i);
for (j = 0; j < slit_table->locality_count; j++) {
if (!pxm_bit_test(j))
continue;
node_to = pxm_to_node(j);
node_distance(node_from, node_to) =
slit_table->entry[i * slit_table->locality_count +
j];
}
}
...
}
num_online_nodes() is a variable value, during system boot the return
vale is 4,
but after offline node2, the return value is 3, so we read a wrong node
distance value.
This patch is trying to fix this bug.
Signed-off-by: Jianguo Wu <wujian...@huawei.com>
---
arch/ia64/include/asm/numa.h | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/arch/ia64/include/asm/numa.h b/arch/ia64/include/asm/numa.h
index 6a8a27c..2e27ef1 100644
--- a/arch/ia64/include/asm/numa.h
+++ b/arch/ia64/include/asm/numa.h
@@ -59,7 +59,7 @@ extern struct node_cpuid_s node_cpuid[NR_CPUS];
*/
extern u8 numa_slit[MAX_NUMNODES * MAX_NUMNODES];
-#define node_distance(from,to) (numa_slit[(from) * num_online_nodes() + (to)])
+#define node_distance(from,to) (numa_slit[(from) * MAX_NUMNODES + (to)])
extern int paddr_to_nid(unsigned long paddr);
--
1.7.6.1
.
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