memory hotplug: migrate swap cache page (abfc3488) · Commits · e / devices / android_kernel_teracube_2e

In test, some pages in swap-cache can't be migrated, as they aren't rmap. unmap_and_move() ignores swap-cache page which is just read in and hasn't rmap (see the comments in the code), but swap_aops provides .migratepage. Better to migrate such pages instead of ignore them. Signed-off-by:

Shaohua Li <shaohua.li@intel.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Yakui Zhao <yakui.zhao@intel.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

mm/migrate.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -147,7 +147,7 @@ static void remove_migration_pte(struct vm_area_struct *vma,
		static void remove_file_migration_ptes(struct page old, struct page new)
		{
		struct vm_area_struct *vma;
		struct address_space *mapping = page_mapping(new);
		struct address_space *mapping = new->mapping;
		struct prio_tree_iter iter;
		pgoff_t pgoff = new->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);

		@@ -664,13 +664,15 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private,
		* needs to be effective.
		*/
		try_to_free_buffers(page);
		}
		goto rcu_unlock;
		}
		goto skip_unmap;
		}

		/* Establish migration ptes or remove ptes */
		try_to_unmap(page, 1);

		skip_unmap:
		if (!page_mapped(page))
		rc = move_to_new_page(newpage, page);