Commit 203e6e5c authored by Joonsoo Kim's avatar Joonsoo Kim Committed by Linus Torvalds
Browse files

mm/memory_hotplug: remove a wrapper for alloc_migration_target() 



To calculate the correct node to migrate the page for hotplug, we need to
check node id of the page.  Wrapper for alloc_migration_target() exists
for this purpose.

However, Vlastimil informs that all migration source pages come from a
single node.  In this case, we don't need to check the node id for each
page and we don't need to re-set the target nodemask for each page by
using the wrapper.  Set up the migration_target_control once and use it
for all pages.

Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Roman Gushchin <guro@fb.com>
Link: http://lkml.kernel.org/r/1594622517-20681-10-git-send-email-iamjoonsoo.kim@lge.com


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 54608759

mm/memory_hotplug.c

+22 −24
Original line number Diff line number Diff line
@@ -1290,27 +1290,6 @@ found: 
	return 0;

}



static struct page *new_node_page(struct page *page, unsigned long private)

{

	nodemask_t nmask = node_states[N_MEMORY];

	struct migration_target_control mtc = {

		.nid = page_to_nid(page),

		.nmask = &nmask,

		.gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL,

	};



	/*

	 * try to allocate from a different node but reuse this node if there

	 * are no other online nodes to be used (e.g. we are offlining a part

	 * of the only existing node)

	 */

	node_clear(mtc.nid, nmask);

	if (nodes_empty(nmask))

		node_set(mtc.nid, nmask);



	return alloc_migration_target(page, (unsigned long)&mtc);

}



static int

do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)

{
@@ -1370,9 +1349,28 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) 
		put_page(page);

	}

	if (!list_empty(&source)) {

		/* Allocate a new page from the nearest neighbor node */

		ret = migrate_pages(&source, new_node_page, NULL, 0,

					MIGRATE_SYNC, MR_MEMORY_HOTPLUG);

		nodemask_t nmask = node_states[N_MEMORY];

		struct migration_target_control mtc = {

			.nmask = &nmask,

			.gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL,

		};



		/*

		 * We have checked that migration range is on a single zone so

		 * we can use the nid of the first page to all the others.

		 */

		mtc.nid = page_to_nid(list_first_entry(&source, struct page, lru));



		/*

		 * try to allocate from a different node but reuse this node

		 * if there are no other online nodes to be used (e.g. we are

		 * offlining a part of the only existing node)

		 */

		node_clear(mtc.nid, nmask);

		if (nodes_empty(nmask))

			node_set(mtc.nid, nmask);

		ret = migrate_pages(&source, alloc_migration_target, NULL,

			(unsigned long)&mtc, MIGRATE_SYNC, MR_MEMORY_HOTPLUG);

		if (ret) {

			list_for_each_entry(page, &source, lru) {

				pr_warn("migrating pfn %lx failed ret:%d ",

CRA Git | Maintained and supported by SUSTech CRA and CCSE