[PATCH V14 4/4] powerpc/vphn: Fix numa update end-loop bug
From: Michael Bringmann <hidden>
Date: 2017-09-08 20:48:04
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
powerpc/vphn: On Power systems with shared configurations of CPUs and memory, there are some issues with the association of additional CPUs and memory to nodes when hot-adding resources. This patch fixes an end-of-updates processing problem observed occasionally in numa_update_cpu_topology(). Signed-off-by: Michael Bringmann <redacted> --- Changes in V14: -- More code cleanup --- arch/powerpc/mm/numa.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 32f5f8d..ec098b3 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c@@ -1401,16 +1401,22 @@ int numa_update_cpu_topology(bool cpus_locked) for_each_cpu(sibling, cpu_sibling_mask(cpu)) { ud = &updates[i++]; + ud->next = &updates[i]; ud->cpu = sibling; ud->new_nid = new_nid; ud->old_nid = numa_cpu_lookup_table[sibling]; cpumask_set_cpu(sibling, &updated_cpus); - if (i < weight) - ud->next = &updates[i]; } cpu = cpu_last_thread_sibling(cpu); } + /* + * Prevent processing of 'updates' from overflowing array + * where last entry filled in a 'next' pointer. + */ + if (i) + updates[i-1].next = NULL; + pr_debug("Topology update for the following CPUs:\n"); if (cpumask_weight(&updated_cpus)) { for (ud = &updates[0]; ud; ud = ud->next) {