| Message ID | 20141018005040.GB3969@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 2c0a33f9861d38631245f7ef434ecad3413324fb |
| Delegated to: | Michael Ellerman |
| Headers | show |
On Sat, 2014-18-10 at 00:50:40 UTC, Nishanth Aravamudan wrote: > We received a report of warning in kernel/sched/core.c where the sched > group was NULL on an LPAR after a topology update. This seems to occur > because after the topology update has moved the CPUs, cpu_to_node is > returning the old value still, which ends up breaking the consistency of > the NUMA topology in the per-cpu maps. Ensure that we update the per-cpu > fields when we re-map CPUs. This looks like a bug fix, I assume you want it to go in for 3.18 ? cheers
Hi Michael, On 21.10.2014 [15:36:27 +1100], Michael Ellerman wrote: > On Sat, 2014-18-10 at 00:50:40 UTC, Nishanth Aravamudan wrote: > > We received a report of warning in kernel/sched/core.c where the sched > > group was NULL on an LPAR after a topology update. This seems to occur > > because after the topology update has moved the CPUs, cpu_to_node is > > returning the old value still, which ends up breaking the consistency of > > the NUMA topology in the per-cpu maps. Ensure that we update the per-cpu > > fields when we re-map CPUs. > > This looks like a bug fix, I assume you want it to go in for 3.18 ? Yes, please! Thanks, Nish
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 86fdb004ad2f..048be62dc979 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -1488,11 +1488,14 @@ static int update_cpu_topology(void *data) cpu = smp_processor_id(); for (update = data; update; update = update->next) { + int new_nid = update->new_nid; if (cpu != update->cpu) continue; unmap_cpu_from_node(cpu); - map_cpu_to_node(cpu, update->new_nid); + map_cpu_to_node(cpu, new_nid); + set_cpu_numa_node(cpu, new_nid); + set_cpu_numa_mem(cpu, local_memory_node(new_nid)); vdso_getcpu_init(); }
We received a report of warning in kernel/sched/core.c where the sched group was NULL on an LPAR after a topology update. This seems to occur because after the topology update has moved the CPUs, cpu_to_node is returning the old value still, which ends up breaking the consistency of the NUMA topology in the per-cpu maps. Ensure that we update the per-cpu fields when we re-map CPUs. Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>