Commit 05624571 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Andrew Morton
Browse files

mm/shmem: use a folio in shmem_unused_huge_shrink 

When calling split_huge_page() we usually have to find the precise page,
but that's not necessary here because we only need to unlock and put the
folio afterwards.  Saves 231 bytes of text (20% of this function).

Link: https://lkml.kernel.org/r/20220504182857.4013401-17-willy@infradead.org


Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent c28a0e96

mm/shmem.c

+12 −11
Original line number Diff line number Diff line
@@ -554,7 +554,7 @@ static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo, 
	LIST_HEAD(to_remove);

	struct inode *inode;

	struct shmem_inode_info *info;

	struct page *page;

	struct folio *folio;

	unsigned long batch = sc ? sc->nr_to_scan : 128;

	int split = 0;
@@ -598,6 +598,7 @@ static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo, 


	list_for_each_safe(pos, next, &list) {

		int ret;

		pgoff_t index;



		info = list_entry(pos, struct shmem_inode_info, shrinklist);

		inode = &info->vfs_inode;
@@ -605,14 +606,14 @@ static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo, 
		if (nr_to_split && split >= nr_to_split)

			goto move_back;



		page = find_get_page(inode->i_mapping,

				(inode->i_size & HPAGE_PMD_MASK) >> PAGE_SHIFT);

		if (!page)

		index = (inode->i_size & HPAGE_PMD_MASK) >> PAGE_SHIFT;

		folio = filemap_get_folio(inode->i_mapping, index);

		if (!folio)

			goto drop;



		/* No huge page at the end of the file: nothing to split */

		if (!PageTransHuge(page)) {

			put_page(page);

		if (!folio_test_large(folio)) {

			folio_put(folio);

			goto drop;

		}
@@ -623,14 +624,14 @@ static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo, 
		 * Waiting for the lock may lead to deadlock in the

		 * reclaim path.

		 */

		if (!trylock_page(page)) {

			put_page(page);

		if (!folio_trylock(folio)) {

			folio_put(folio);

			goto move_back;

		}



		ret = split_huge_page(page);

		unlock_page(page);

		put_page(page);

		ret = split_huge_page(&folio->page);

		folio_unlock(folio);

		folio_put(folio);



		/* If split failed move the inode on the list back to shrinklist */

		if (ret)