From: Michal Hocko <mhocko@xxxxxxxx> Subject: mm, page_alloc: remove boot pageset initialization from memory hotplug boot_pageset is a boot time hack which gets superseded by normal pagesets later in the boot process. It makes zero sense to reinitialize it again and again during memory hotplug. Link: http://lkml.kernel.org/r/20170721143915.14161-3-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 | 40 ++++++++++++++++++++++------------------ 1 file changed, 22 insertions(+), 18 deletions(-) diff -puN mm/page_alloc.c~mm-page_alloc-remove-boot-pageset-initialization-from-memory-hotplug mm/page_alloc.c --- a/mm/page_alloc.c~mm-page_alloc-remove-boot-pageset-initialization-from-memory-hotplug +++ a/mm/page_alloc.c @@ -5141,7 +5141,7 @@ DEFINE_MUTEX(zonelists_mutex); static int __build_all_zonelists(void *data) { int nid; - int cpu; + int __maybe_unused cpu; pg_data_t *self = data; #ifdef CONFIG_NUMA @@ -5162,23 +5162,8 @@ static int __build_all_zonelists(void *d } } - /* - * Initialize the boot_pagesets that are going to be used - * for bootstrapping processors. The real pagesets for - * each zone will be allocated later when the per cpu - * allocator is available. - * - * boot_pagesets are used also for bootstrapping offline - * cpus if the system is already booted because the pagesets - * are needed to initialize allocators on a specific cpu too. - * F.e. the percpu allocator needs the page allocator which - * needs the percpu allocator in order to allocate its pagesets - * (a chicken-egg dilemma). - */ - for_each_possible_cpu(cpu) { - setup_pageset(&per_cpu(boot_pageset, cpu), 0); - #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. @@ -5189,8 +5174,8 @@ static int __build_all_zonelists(void *d */ if (cpu_online(cpu)) set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu))); -#endif } +#endif return 0; } @@ -5198,7 +5183,26 @@ static int __build_all_zonelists(void *d static noinline void __init build_all_zonelists_init(void) { + int cpu; + __build_all_zonelists(NULL); + + /* + * Initialize the boot_pagesets that are going to be used + * for bootstrapping processors. The real pagesets for + * each zone will be allocated later when the per cpu + * allocator is available. + * + * boot_pagesets are used also for bootstrapping offline + * cpus if the system is already booted because the pagesets + * are needed to initialize allocators on a specific cpu too. + * F.e. the percpu allocator needs the page allocator which + * needs the percpu allocator in order to allocate its pagesets + * (a chicken-egg dilemma). + */ + for_each_possible_cpu(cpu) + setup_pageset(&per_cpu(boot_pageset, cpu), 0); + mminit_verify_zonelist(); cpuset_init_current_mems_allowed(); } _ -- 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
