[patch 45/67] cpu to node relationship fixup: map cpu to node

Greg KH
2006-10-11T21:08:50Z

[-- Attachment #1: cpu-to-node-relationship-fixup-map-cpu-to-node.patch --]
[-- Type: text/plain, Size: 3368 bytes --]

-stable review patch. If anyone has any objections, please let us know.

------------------
From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>

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: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
arch/ia64/kernel/numa.c | 34 +++++++++++++++++++++++++++++++---
arch/ia64/kernel/topology.c | 4 +++-
include/asm-ia64/numa.h | 6 ++++++
3 files changed, 40 insertions(+), 4 deletions(-)

--- linux-2.6.18.orig/arch/ia64/kernel/numa.c
+++ linux-2.6.18/arch/ia64/kernel/numa.c
@@ -29,6 +29,36 @@ EXPORT_SYMBOL(cpu_to_node_map);

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 @@ void __init build_cpu_to_node_map(void)
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);
}
}
--- linux-2.6.18.orig/arch/ia64/kernel/topology.c
+++ linux-2.6.18/arch/ia64/kernel/topology.c
@@ -36,6 +36,7 @@ int arch_register_cpu(int num)
*/
if (!can_cpei_retarget() && is_cpu_cpei_target(num))
sysfs_cpus[num].cpu.no_control = 1;
+ map_cpu_to_node(num, node_cpuid[num].nid);
#endif

return register_cpu(&sysfs_cpus[num].cpu, num);
@@ -45,7 +46,8 @@ int arch_register_cpu(int num)

void arch_unregister_cpu(int num)
{
- return unregister_cpu(&sysfs_cpus[num].cpu);
+ unregister_cpu(&sysfs_cpus[num].cpu);
+ unmap_cpu_from_node(num, cpu_to_node(num));
}
EXPORT_SYMBOL(arch_register_cpu);
EXPORT_SYMBOL(arch_unregister_cpu);
--- linux-2.6.18.orig/include/asm-ia64/numa.h
+++ linux-2.6.18/include/asm-ia64/numa.h
@@ -64,7 +64,13 @@ extern int paddr_to_nid(unsigned long pa

#define local_nodeid (cpu_to_node_map[smp_processor_id()])

+extern void map_cpu_to_node(int cpu, int nid);
+extern void unmap_cpu_from_node(int cpu, int nid);
+
+
#else /* !CONFIG_NUMA */
+#define map_cpu_to_node(cpu, nid) do{}while(0)
+#define unmap_cpu_from_node(cpu, nid) do{}while(0)

#define paddr_to_nid(addr) 0

--