On shared processor LPARs, H_HOME_NODE_ASSOCIATIVITY hcall provides the
dynamic virtual-physical mapping for any given processor. Currently we
use VPHN node ID information only after getting either a PRRN or a VPHN
event. But during boot time inside the function numa_setup_cpu, we still
query the OF device tree for the node ID value which might be different
than what can be fetched from the H_HOME_NODE_ASSOCIATIVITY hcall. In a
scenario where there are no PRRN or VPHN event after boot, all node-cpu
mapping will remain incorrect there after.
With this proposed change, numa_setup_cpu will try to override the OF
device tree fetched node ID information with H_HOME_NODE_ASSOCIATIVITY
hcall fetched node ID value. Right now shared processor property of the
LPAR cannot be queried as VPA inializaion happens after numa_setup_cpu
during boot time. So initmem_init function has been moved after ppc_md.
setup_arch inside setup_arch during boot.
Signed-off-by: Anshuman Khandual <khand...@linux.vnet.ibm.com>
---
Before the change:
# numactl -H
available: 2 nodes (0,3)
node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
25 26 27 28 29 30 31
node 0 size: 0 MB
node 0 free: 0 MB
node 3 cpus:
node 3 size: 16315 MB
node 3 free: 15716 MB
node distances:
node 0 3
0: 10 20
3: 20 10
After the change:
# numactl -H
available: 2 nodes (0,3)
node 0 cpus:
node 0 size: 0 MB
node 0 free: 0 MB
node 3 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
25 26 27 28 29 30 31
node 3 size: 16315 MB
node 3 free: 15537 MB
node distances:
node 0 3
0: 10 20
3: 20 10
arch/powerpc/kernel/setup_64.c | 2 +-
arch/powerpc/mm/numa.c | 27 ++++++++++++++++++++++++---
2 files changed, 25 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index bdcbb71..56026b7 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -694,7 +694,6 @@ void __init setup_arch(char **cmdline_p)
exc_lvl_early_init();
emergency_stack_init();
- initmem_init();
#ifdef CONFIG_DUMMY_CONSOLE
conswitchp = &dummy_con;
@@ -703,6 +702,7 @@ void __init setup_arch(char **cmdline_p)
if (ppc_md.setup_arch)
ppc_md.setup_arch();
+ initmem_init();
paging_init();
/* Initialize the MMU context management stuff */
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 8b9502a..e404d05 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -41,6 +41,10 @@
#include <asm/setup.h>
#include <asm/vdso.h>
+#ifdef CONFIG_PPC_SPLPAR
+static int vphn_get_node(unsigned int cpu);
+#endif
+
static int numa_enabled = 1;
static char *cmdline __initdata;
@@ -553,6 +557,17 @@ static int numa_setup_cpu(unsigned long lcpu)
nid = of_node_to_nid_single(cpu);
+ /*
+ * Override the OF device tree fetched node number
+ * with VPHN based node number in case of a shared
+ * processor LPAR on PHYP platform.
+ */
+#ifdef CONFIG_PPC_SPLPAR
+ if (lppaca_shared_proc(get_lppaca())) {
+ nid = vphn_get_node(lcpu);
+ }
+#endif
+
out_present:
if (nid < 0 || !node_online(nid))
nid = first_online_node;
@@ -1364,6 +1379,14 @@ static int update_lookup_table(void *data)
return 0;
}
+static int vphn_get_node(unsigned int cpu)
+{
+ __be32 associativity[VPHN_ASSOC_BUFSIZE] = {0};
+
+ vphn_get_associativity(cpu, associativity);
+ return associativity_to_nid(associativity);
+}
+
/*
* Update the node maps and sysfs entries for each cpu whose home node
* has changed. Returns 1 when the topology has changed, and 0 otherwise.
@@ -1372,7 +1395,6 @@ int arch_update_cpu_topology(void)
{
unsigned int cpu, sibling, changed = 0;
struct topology_update_data *updates, *ud;
- __be32 associativity[VPHN_ASSOC_BUFSIZE] = {0};
cpumask_t updated_cpus;
struct device *dev;
int weight, new_nid, i = 0;
@@ -1408,8 +1430,7 @@ int arch_update_cpu_topology(void)
}
/* Use associativity from first thread for all siblings */
- vphn_get_associativity(cpu, associativity);
- new_nid = associativity_to_nid(associativity);
+ new_nid = vphn_get_node(cpu);
if (new_nid < 0 || !node_online(new_nid))
new_nid = first_online_node;
--
2.1.0
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