Commit c33db292 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Andrew Morton
Browse files

migrate: convert unmap_and_move_huge_page() to use folios 

Saves several calls to compound_head() and removes a couple of uses of
page->lru.

Link: https://lkml.kernel.org/r/20220902194653.1739778-52-willy@infradead.org


Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 682a71a1

mm/migrate.c

+14 −14
Original line number Diff line number Diff line
@@ -1263,7 +1263,7 @@ static int unmap_and_move_huge_page(new_page_t get_new_page, 
	if (!hugepage_migration_supported(page_hstate(hpage)))

		return -ENOSYS;



	if (page_count(hpage) == 1) {

	if (folio_ref_count(src) == 1) {

		/* page was freed from under us. So we are done. */

		putback_active_hugepage(hpage);

		return MIGRATEPAGE_SUCCESS;
@@ -1274,7 +1274,7 @@ static int unmap_and_move_huge_page(new_page_t get_new_page, 
		return -ENOMEM;

	dst = page_folio(new_hpage);



	if (!trylock_page(hpage)) {

	if (!folio_trylock(src)) {

		if (!force)

			goto out;

		switch (mode) {
@@ -1284,29 +1284,29 @@ static int unmap_and_move_huge_page(new_page_t get_new_page, 
		default:

			goto out;

		}

		lock_page(hpage);

		folio_lock(src);

	}



	/*

	 * Check for pages which are in the process of being freed.  Without

	 * page_mapping() set, hugetlbfs specific move page routine will not

	 * folio_mapping() set, hugetlbfs specific move page routine will not

	 * be called and we could leak usage counts for subpools.

	 */

	if (hugetlb_page_subpool(hpage) && !page_mapping(hpage)) {

	if (hugetlb_page_subpool(hpage) && !folio_mapping(src)) {

		rc = -EBUSY;

		goto out_unlock;

	}



	if (PageAnon(hpage))

		anon_vma = page_get_anon_vma(hpage);

	if (folio_test_anon(src))

		anon_vma = page_get_anon_vma(&src->page);



	if (unlikely(!trylock_page(new_hpage)))

	if (unlikely(!folio_trylock(dst)))

		goto put_anon;



	if (page_mapped(hpage)) {

	if (folio_mapped(src)) {

		enum ttu_flags ttu = 0;



		if (!PageAnon(hpage)) {

		if (!folio_test_anon(src)) {

			/*

			 * In shared mappings, try_to_unmap could potentially

			 * call huge_pmd_unshare.  Because of this, take
@@ -1327,7 +1327,7 @@ static int unmap_and_move_huge_page(new_page_t get_new_page, 
			i_mmap_unlock_write(mapping);

	}



	if (!page_mapped(hpage))

	if (!folio_mapped(src))

		rc = move_to_new_folio(dst, src, mode);



	if (page_was_mapped)
@@ -1335,7 +1335,7 @@ static int unmap_and_move_huge_page(new_page_t get_new_page, 
			rc == MIGRATEPAGE_SUCCESS ? dst : src, false);



unlock_put_anon:

	unlock_page(new_hpage);

	folio_unlock(dst);



put_anon:

	if (anon_vma)
@@ -1347,12 +1347,12 @@ static int unmap_and_move_huge_page(new_page_t get_new_page, 
	}



out_unlock:

	unlock_page(hpage);

	folio_unlock(src);

out:

	if (rc == MIGRATEPAGE_SUCCESS)

		putback_active_hugepage(hpage);

	else if (rc != -EAGAIN)

		list_move_tail(&hpage->lru, ret);

		list_move_tail(&src->lru, ret);



	/*

	 * If migration was not successful and there's a freeing callback, use