From: Michal Hocko <mhocko@xxxxxxxx> Subject: mm, page_alloc: do not set_cpu_numa_mem on empty nodes initialization __build_all_zonelists reinitializes each online cpu local node for CONFIG_HAVE_MEMORYLESS_NODES. This makes sense because previously memory less nodes could gain some memory during memory hotplug and so the local node should be changed for CPUs close to such a node. It makes less sense to do that unconditionally for a newly creaded NUMA node which is still offline and without any memory. Let's also simplify the cpu loop and use for_each_online_cpu instead of an explicit cpu_online check for all possible cpus. Link: http://lkml.kernel.org/r/20170721143915.14161-4-mhocko@xxxxxxxxxx Signed-off-by: Michal Hocko <mhocko@xxxxxxxx> Acked-by: Mel Gorman <mgorman@xxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Joonsoo Kim <js1304@xxxxxxxxx> Cc: Shaohua Li <shaohua.li@xxxxxxxxx> Cc: Toshi Kani <toshi.kani@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/page_alloc.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff -puN mm/page_alloc.c~mm-page_alloc-do-not-set_cpu_numa_mem-on-empty-nodes-initialization mm/page_alloc.c --- a/mm/page_alloc.c~mm-page_alloc-do-not-set_cpu_numa_mem-on-empty-nodes-initialization +++ a/mm/page_alloc.c @@ -5160,10 +5160,8 @@ static int __build_all_zonelists(void *d build_zonelists(pgdat); } - } #ifdef CONFIG_HAVE_MEMORYLESS_NODES - for_each_possible_cpu(cpu) { /* * We now know the "local memory node" for each node-- * i.e., the node of the first zone in the generic zonelist. @@ -5172,10 +5170,10 @@ static int __build_all_zonelists(void *d * secondary cpus' numa_mem as they come on-line. During * node/memory hotplug, we'll fixup all on-line cpus. */ - if (cpu_online(cpu)) + for_each_online_cpu(cpu) set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu))); - } #endif + } return 0; } _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
