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Commit 394e31d2 authored by Xishi Qiu's avatar Xishi Qiu Committed by Linus Torvalds
Browse files

mem-hotplug: alloc new page from a nearest neighbor node when mem-offline 

If we offline a node, alloc the new page from a nearest neighbor node
instead of the current node or other remote nodes, because re-migrate is
a waste of time and the distance of the remote nodes is often very
large.

Also use GFP_HIGHUSER_MOVABLE to alloc new page if the zone is movable
zone or highmem zone.

Link: http://lkml.kernel.org/r/5795E18B.5060302@huawei.com


Signed-off-by: default avatarXishi Qiu <qiuxishi@huawei.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3fa6c507

mm/memory_hotplug.c

+33 −5
Original line number Diff line number Diff line
@@ -1548,6 +1548,37 @@ static unsigned long scan_movable_pages(unsigned long start, unsigned long end) 
	return 0;

}



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

		int **result)

{

	gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE;

	int nid = page_to_nid(page);

	nodemask_t nmask = node_online_map;

	struct page *new_page;



	/*

	 * TODO: allocate a destination hugepage from a nearest neighbor node,

	 * accordance with memory policy of the user process if possible. For

	 * now as a simple work-around, we use the next node for destination.

	 */

	if (PageHuge(page))

		return alloc_huge_page_node(page_hstate(compound_head(page)),

					next_node_in(nid, nmask));



	node_clear(nid, nmask);

	if (PageHighMem(page)

	    || (zone_idx(page_zone(page)) == ZONE_MOVABLE))

		gfp_mask |= __GFP_HIGHMEM;



	new_page = __alloc_pages_nodemask(gfp_mask, 0,

					node_zonelist(nid, gfp_mask), &nmask);

	if (!new_page)

		new_page = __alloc_pages(gfp_mask, 0,

					node_zonelist(nid, gfp_mask));



	return new_page;

}



#define NR_OFFLINE_AT_ONCE_PAGES	(256)

static int

do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
@@ -1611,11 +1642,8 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) 
			goto out;

		}



		/*

		 * alloc_migrate_target should be improooooved!!

		 * migrate_pages returns # of failed pages.

		 */

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

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

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

					MIGRATE_SYNC, MR_MEMORY_HOTPLUG);

		if (ret)

			putback_movable_pages(&source);