From 70b5b46a754245d383811b4d2f2c76c34bb7e145 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Tue, 22 Mar 2022 14:47:00 -0700 Subject: [PATCH] mm, memory_hotplug: reorganize new pgdat initialization When a !node_online node is brought up it needs a hotplug specific initialization because the node could be either uninitialized yet or it could have been recycled after previous hotremove. hotadd_init_pgdat is responsible for that. Internal pgdat state is initialized at two places currently - hotadd_init_pgdat - free_area_init_core_hotplug There is no real clear cut what should go where but this patch's chosen to move the whole internal state initialization into free_area_init_core_hotplug. hotadd_init_pgdat is still responsible to pull all the parts together - most notably to initialize zonelists because those depend on the overall topology. This patch doesn't introduce any functional change. Link: https://lkml.kernel.org/r/20220127085305.20890-5-mhocko@kernel.org Signed-off-by: Michal Hocko Acked-by: Rafael Aquini Acked-by: David Hildenbrand Reviewed-by: Oscar Salvador Cc: Alexey Makhalov Cc: Christoph Lameter Cc: Dennis Zhou Cc: Eric Dumazet Cc: Mike Rapoport Cc: Nico Pache Cc: Tejun Heo Cc: Wei Yang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memory_hotplug.h | 2 +- mm/memory_hotplug.c | 28 +++------------------------- mm/page_alloc.c | 25 +++++++++++++++++++++++-- 3 files changed, 27 insertions(+), 28 deletions(-) diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 60f09d3..76bf2de 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -319,7 +319,7 @@ extern void set_zone_contiguous(struct zone *zone); extern void clear_zone_contiguous(struct zone *zone); #ifdef CONFIG_MEMORY_HOTPLUG -extern void __ref free_area_init_core_hotplug(int nid); +extern void __ref free_area_init_core_hotplug(struct pglist_data *pgdat); extern int __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags); extern int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags); extern int add_memory_resource(int nid, struct resource *resource, diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 55c3e53..a4f69d3 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1166,39 +1166,16 @@ static pg_data_t __ref *hotadd_init_pgdat(int nid) { struct pglist_data *pgdat; - pgdat = NODE_DATA(nid); - /* * NODE_DATA is preallocated (free_area_init) but its internal * state is not allocated completely. Add missing pieces. * Completely offline nodes stay around and they just need * reintialization. */ - if (pgdat->per_cpu_nodestats == &boot_nodestats) { - pgdat->per_cpu_nodestats = - alloc_percpu(struct per_cpu_nodestat); - } else { - int cpu; - /* - * Reset the nr_zones, order and highest_zoneidx before reuse. - * Note that kswapd will init kswapd_highest_zoneidx properly - * when it starts in the near future. - */ - pgdat->nr_zones = 0; - pgdat->kswapd_order = 0; - pgdat->kswapd_highest_zoneidx = 0; - for_each_online_cpu(cpu) { - struct per_cpu_nodestat *p; - - p = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu); - memset(p, 0, sizeof(*p)); - } - } - - pgdat->node_start_pfn = 0; + pgdat = NODE_DATA(nid); /* init node's zones as empty zones, we don't have any present pages.*/ - free_area_init_core_hotplug(nid); + free_area_init_core_hotplug(pgdat); /* * The node we allocated has no zone fallback lists. For avoiding @@ -1210,6 +1187,7 @@ static pg_data_t __ref *hotadd_init_pgdat(int nid) * When memory is hot-added, all the memory is in offline state. So * clear all zones' present_pages because they will be updated in * online_pages() and offline_pages(). + * TODO: should be in free_area_init_core_hotplug? */ reset_node_managed_pages(pgdat); reset_node_present_pages(pgdat); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 4f141a4..d32a635 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -7466,12 +7466,33 @@ static void __meminit zone_init_internals(struct zone *zone, enum zone_type idx, * NOTE: this function is only called during memory hotplug */ #ifdef CONFIG_MEMORY_HOTPLUG -void __ref free_area_init_core_hotplug(int nid) +void __ref free_area_init_core_hotplug(struct pglist_data *pgdat) { + int nid = pgdat->node_id; enum zone_type z; - pg_data_t *pgdat = NODE_DATA(nid); + int cpu; pgdat_init_internals(pgdat); + + if (pgdat->per_cpu_nodestats == &boot_nodestats) + pgdat->per_cpu_nodestats = alloc_percpu(struct per_cpu_nodestat); + + /* + * Reset the nr_zones, order and highest_zoneidx before reuse. + * Note that kswapd will init kswapd_highest_zoneidx properly + * when it starts in the near future. + */ + pgdat->nr_zones = 0; + pgdat->kswapd_order = 0; + pgdat->kswapd_highest_zoneidx = 0; + pgdat->node_start_pfn = 0; + for_each_online_cpu(cpu) { + struct per_cpu_nodestat *p; + + p = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu); + memset(p, 0, sizeof(*p)); + } + for (z = 0; z < MAX_NR_ZONES; z++) zone_init_internals(&pgdat->node_zones[z], z, nid, 0); } -- 2.7.4