Commit 83d5fe73 authored by Michal Hocko's avatar Michal Hocko Committed by Wupeng Ma
Browse files

mm, memory_hotplug: reorganize new pgdat initialization 

mainline inclusion
from mainline-v5.18-rc1
commit 70b5b46a
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8EQ3K

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=70b5b46a754245d383811b4d2f2c76c34bb7e145

--------------------------------

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: default avatarMichal Hocko <mhocko@suse.com>
Acked-by: default avatarRafael Aquini <raquini@redhat.com>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Reviewed-by: default avatarOscar Salvador <osalvador@suse.de>
Cc: Alexey Makhalov <amakhalov@vmware.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>

Conflicts:
	include/linux/memory_hotplug.h
Signed-off-by: default avatarMa Wupeng <mawupeng1@huawei.com>
parent b8adb5c3

include/linux/memory_hotplug.h

+1 −1
Original line number Diff line number Diff line
@@ -314,7 +314,7 @@ extern void clear_zone_contiguous(struct zone *zone); 
#ifdef CONFIG_MEMORY_HOTPLUG

extern struct acpi_device *hotplug_mdev[MAX_NUMNODES];



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,

mm/memory_hotplug.c

+3 −25
Original line number Diff line number Diff line
@@ -768,39 +768,16 @@ 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
@@ -812,6 +789,7 @@ 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);

mm/page_alloc.c

+23 −2
Original line number Diff line number Diff line
@@ -7430,12 +7430,33 @@ 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);

}