[PATCH] cpu to node relationship fixup: map cpu to node
Assume that a cpu is *physically* offlined at boot time...
Because smpboot.c::smp_boot_cpu_map() canoot find cpu's sapicid,
numa.c::build_cpu_to_node_map() cannot build cpu<->node map for
offlined cpu.
For such cpus, cpu_to_node map should be fixed at cpu-hot-add.
This mapping should be done before cpu onlining.
This patch also handles cpu hotremove case.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/ia64/kernel/numa.c b/arch/ia64/kernel/numa.c
index 1cc360c..2034063 100644
--- a/arch/ia64/kernel/numa.c
+++ b/arch/ia64/kernel/numa.c
@@ -29,6 +29,36 @@
cpumask_t node_to_cpu_mask[MAX_NUMNODES] __cacheline_aligned;
+void __cpuinit map_cpu_to_node(int cpu, int nid)
+{
+ int oldnid;
+ if (nid < 0) { /* just initialize by zero */
+ cpu_to_node_map[cpu] = 0;
+ return;
+ }
+ /* sanity check first */
+ oldnid = cpu_to_node_map[cpu];
+ if (cpu_isset(cpu, node_to_cpu_mask[oldnid])) {
+ return; /* nothing to do */
+ }
+ /* we don't have cpu-driven node hot add yet...
+ In usual case, node is created from SRAT at boot time. */
+ if (!node_online(nid))
+ nid = first_online_node;
+ cpu_to_node_map[cpu] = nid;
+ cpu_set(cpu, node_to_cpu_mask[nid]);
+ return;
+}
+
+void __cpuinit unmap_cpu_from_node(int cpu, int nid)
+{
+ WARN_ON(!cpu_isset(cpu, node_to_cpu_mask[nid]));
+ WARN_ON(cpu_to_node_map[cpu] != nid);
+ cpu_to_node_map[cpu] = 0;
+ cpu_clear(cpu, node_to_cpu_mask[nid]);
+}
+
+
/**
* build_cpu_to_node_map - setup cpu to node and node to cpumask arrays
*
@@ -49,8 +79,6 @@
node = node_cpuid[i].nid;
break;
}
- cpu_to_node_map[cpu] = (node >= 0) ? node : 0;
- if (node >= 0)
- cpu_set(cpu, node_to_cpu_mask[node]);
+ map_cpu_to_node(cpu, node);
}
}