This function will be used imminently.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
include/linux/mm.h | 7 ++++++
mm/swap.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 63 insertions(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index a517ef8d2386..4f9e2cfb372e 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1515,6 +1515,13 @@ typedef union {
void release_pages(release_pages_arg, int nr);
void folios_put(struct folio_batch *folios);
+struct pfn_range {
+ unsigned long start;
+ unsigned long end;
+};
+
+void pfn_range_put(struct pfn_range *range, unsigned int nr);
+
static inline void put_page(struct page *page)
{
struct folio *folio = page_folio(page);
diff --git a/mm/swap.c b/mm/swap.c
index 8bd15402cd8f..218d2cc4c6f4 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -1027,6 +1027,62 @@ void folios_put(struct folio_batch *folios)
}
EXPORT_SYMBOL(folios_put);
+void pfn_range_put(struct pfn_range *range, unsigned int nr)
+{
+ struct folio_batch folios;
+ unsigned int i;
+ struct lruvec *lruvec = NULL;
+ unsigned long flags = 0;
+
+ folio_batch_init(&folios);
+ for (i = 0; i < nr; i++) {
+ struct folio *folio = pfn_folio(range[i].start);
+ unsigned int refs = range[i].end - range[i].start;
+
+ if (folio_is_zone_device(folio)) {
+ if (lruvec) {
+ unlock_page_lruvec_irqrestore(lruvec, flags);
+ lruvec = NULL;
+ }
+ if (put_devmap_managed_page_refs(&folio->page, refs))
+ continue;
+ if (folio_ref_sub_and_test(folio, refs))
+ free_zone_device_page(&folio->page);
+ continue;
+ }
+
+ if (!folio_ref_sub_and_test(folio, refs))
+ continue;
+
+ /* hugetlb has its own memcg */
+ if (folio_test_hugetlb(folio)) {
+ if (lruvec) {
+ unlock_page_lruvec_irqrestore(lruvec, flags);
+ lruvec = NULL;
+ }
+ free_huge_folio(folio);
+ continue;
+ }
+
+ __page_cache_release(folio, &lruvec, &flags);
+ if (folio_batch_add(&folios, folio) == 0) {
+ if (lruvec) {
+ unlock_page_lruvec_irqrestore(lruvec, flags);
+ lruvec = NULL;
+ }
+ mem_cgroup_uncharge_folios(&folios);
+ free_unref_folios(&folios);
+ }
+ }
+ if (lruvec)
+ unlock_page_lruvec_irqrestore(lruvec, flags);
+
+ if (folios.nr) {
+ mem_cgroup_uncharge_folios(&folios);
+ free_unref_folios(&folios);
+ }
+}
+
/**
* release_pages - batched put_page()
* @arg: array of pages to release
--
2.40.1
