mem-hotplug: alloc new page from a nearest neighbor node when mem-offline (394e31d2) · Commits · 戴 / test

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);

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