Commit 5acc17fd authored by Kefeng Wang's avatar Kefeng Wang Committed by Andrew Morton
Browse files

mm: page_idle: convert page idle to use a folio 

Firstly, make page_idle_get_page() return a folio, also rename it to
page_idle_get_folio(), then, use it to convert page_idle_bitmap_read() and
page_idle_bitmap_write() functions.

Link: https://lkml.kernel.org/r/20221230070849.63358-3-wangkefeng.wang@huawei.com


Signed-off-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: default avatarSeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent becacb04

mm/page_idle.c

+24 −23
Original line number Diff line number Diff line
@@ -31,19 +31,22 @@ 
 *

 * This function tries to get a user memory page by pfn as described above.

 */

static struct page *page_idle_get_page(unsigned long pfn)

static struct folio *page_idle_get_folio(unsigned long pfn)

{

	struct page *page = pfn_to_online_page(pfn);

	struct folio *folio;



	if (!page || !PageLRU(page) ||

	    !get_page_unless_zero(page))

	if (!page || PageTail(page))

		return NULL;



	if (unlikely(!PageLRU(page))) {

		put_page(page);

		page = NULL;

	folio = page_folio(page);

	if (!folio_test_lru(folio) || !folio_try_get(folio))

		return NULL;

	if (unlikely(page_folio(page) != folio || !folio_test_lru(folio))) {

		folio_put(folio);

		folio = NULL;

	}

	return page;

	return folio;

}



static bool page_idle_clear_pte_refs_one(struct folio *folio,
@@ -83,10 +86,8 @@ static bool page_idle_clear_pte_refs_one(struct folio *folio, 
	return true;

}



static void page_idle_clear_pte_refs(struct page *page)

static void page_idle_clear_pte_refs(struct folio *folio)

{

	struct folio *folio = page_folio(page);



	/*

	 * Since rwc.try_lock is unused, rwc is effectively immutable, so we

	 * can make it static to save some cycles and stack.
@@ -115,7 +116,7 @@ static ssize_t page_idle_bitmap_read(struct file *file, struct kobject *kobj, 
				     loff_t pos, size_t count)

{

	u64 *out = (u64 *)buf;

	struct page *page;

	struct folio *folio;

	unsigned long pfn, end_pfn;

	int bit;
@@ -134,19 +135,19 @@ static ssize_t page_idle_bitmap_read(struct file *file, struct kobject *kobj, 
		bit = pfn % BITMAP_CHUNK_BITS;

		if (!bit)

			*out = 0ULL;

		page = page_idle_get_page(pfn);

		if (page) {

			if (page_is_idle(page)) {

		folio = page_idle_get_folio(pfn);

		if (folio) {

			if (folio_test_idle(folio)) {

				/*

				 * The page might have been referenced via a

				 * pte, in which case it is not idle. Clear

				 * refs and recheck.

				 */

				page_idle_clear_pte_refs(page);

				if (page_is_idle(page))

				page_idle_clear_pte_refs(folio);

				if (folio_test_idle(folio))

					*out |= 1ULL << bit;

			}

			put_page(page);

			folio_put(folio);

		}

		if (bit == BITMAP_CHUNK_BITS - 1)

			out++;
@@ -160,7 +161,7 @@ static ssize_t page_idle_bitmap_write(struct file *file, struct kobject *kobj, 
				      loff_t pos, size_t count)

{

	const u64 *in = (u64 *)buf;

	struct page *page;

	struct folio *folio;

	unsigned long pfn, end_pfn;

	int bit;
@@ -178,11 +179,11 @@ static ssize_t page_idle_bitmap_write(struct file *file, struct kobject *kobj, 
	for (; pfn < end_pfn; pfn++) {

		bit = pfn % BITMAP_CHUNK_BITS;

		if ((*in >> bit) & 1) {

			page = page_idle_get_page(pfn);

			if (page) {

				page_idle_clear_pte_refs(page);

				set_page_idle(page);

				put_page(page);

			folio = page_idle_get_folio(pfn);

			if (folio) {

				page_idle_clear_pte_refs(folio);

				folio_set_idle(folio);

				folio_put(folio);

			}

		}

		if (bit == BITMAP_CHUNK_BITS - 1)