[PATCH mm-unstable 1/8] mm/hugetlb: convert isolate_hugetlb to folios

Sidhartha Kumar
2023-01-03T19:17:04Z

Convert isolate_hugetlb() to take in a folio and convert its callers to
pass a folio. Using page_folio() to convert the callers to use a folio is
safe as isolate_hugetlb() operates on a head page.

Also add a folio equivalent of get_page_unless_zero().

Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
---
include/linux/hugetlb.h | 4 ++--
include/linux/mm.h | 5 +++++
mm/gup.c | 2 +-
mm/hugetlb.c | 16 ++++++++--------
mm/memory-failure.c | 2 +-
mm/memory_hotplug.c | 2 +-
mm/mempolicy.c | 2 +-
mm/migrate.c | 2 +-
8 files changed, 20 insertions(+), 15 deletions(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 551834cd5299..482929b2d044 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -169,7 +169,7 @@ bool hugetlb_reserve_pages(struct inode *inode, long from, long to,
vm_flags_t vm_flags);
long hugetlb_unreserve_pages(struct inode *inode, long start, long end,
long freed);
-int isolate_hugetlb(struct page *page, struct list_head *list);
+int isolate_hugetlb(struct folio *folio, struct list_head *list);
int get_hwpoison_huge_page(struct page *page, bool *hugetlb, bool unpoison);
int get_huge_page_for_hwpoison(unsigned long pfn, int flags,
bool *migratable_cleared);
@@ -374,7 +374,7 @@ static inline pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr,
return NULL;
}

-static inline int isolate_hugetlb(struct page *page, struct list_head *list)
+static inline int isolate_hugetlb(struct folio *folio, struct list_head *list)
{
return -EBUSY;
}
diff --git a/include/linux/mm.h b/include/linux/mm.h
index e2dd5a37d078..cd8508d728f1 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -775,6 +775,11 @@ static inline bool get_page_unless_zero(struct page *page)
return page_ref_add_unless(page, 1, 0);
}

+static inline bool get_folio_unless_zero(struct folio *folio)
+{
+ return folio_ref_add_unless(folio, 1, 0);
+}
+
extern int page_is_ram(unsigned long pfn);

enum {
diff --git a/mm/gup.c b/mm/gup.c
index 5182abaaecde..bdb00b9df89e 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1843,7 +1843,7 @@ static unsigned long collect_longterm_unpinnable_pages(
continue;

if (folio_test_hugetlb(folio)) {
- isolate_hugetlb(&folio->page, movable_page_list);
+ isolate_hugetlb(folio, movable_page_list);
continue;
}

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 0c58f6519b9a..90c6f0402c7b 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2781,7 +2781,7 @@ static int alloc_and_dissolve_hugetlb_folio(struct hstate *h,
* Fail with -EBUSY if not possible.
*/
spin_unlock_irq(&hugetlb_lock);
- ret = isolate_hugetlb(&old_folio->page, list);
+ ret = isolate_hugetlb(old_folio, list);
spin_lock_irq(&hugetlb_lock);
goto free_new;
} else if (!folio_test_hugetlb_freed(old_folio)) {
@@ -2856,7 +2856,7 @@ int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list)
if (hstate_is_gigantic(h))
return -ENOMEM;

- if (folio_ref_count(folio) && !isolate_hugetlb(&folio->page, list))
+ if (folio_ref_count(folio) && !isolate_hugetlb(folio, list))
ret = 0;
else if (!folio_ref_count(folio))
ret = alloc_and_dissolve_hugetlb_folio(h, folio, list);
@@ -7271,19 +7271,19 @@ __weak unsigned long hugetlb_mask_last_page(struct hstate *h)
* These functions are overwritable if your architecture needs its own
* behavior.
*/
-int isolate_hugetlb(struct page *page, struct list_head *list)
+int isolate_hugetlb(struct folio *folio, struct list_head *list)
{
int ret = 0;

spin_lock_irq(&hugetlb_lock);
- if (!PageHeadHuge(page) ||
- !HPageMigratable(page) ||
- !get_page_unless_zero(page)) {
+ if (!folio_test_hugetlb(folio) ||
+ !folio_test_hugetlb_migratable(folio) ||
+ !get_folio_unless_zero(folio)) {
ret = -EBUSY;
goto unlock;
}
- ClearHPageMigratable(page);
- list_move_tail(&page->lru, list);
+ folio_clear_hugetlb_migratable(folio);
+ list_move_tail(&folio->lru, list);
unlock:
spin_unlock_irq(&hugetlb_lock);
return ret;
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 63d8501001c6..cf60c0fa795c 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -2438,7 +2438,7 @@ static bool isolate_page(struct page *page, struct list_head *pagelist)
bool isolated = false;

if (PageHuge(page)) {
- isolated = !isolate_hugetlb(page, pagelist);
+ isolated = !isolate_hugetlb(page_folio(page), pagelist);
} else {
bool lru = !__PageMovable(page);

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index fd40f7e9f176..a1e8c3e9ab08 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1641,7 +1641,7 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)

if (PageHuge(page)) {
pfn = page_to_pfn(head) + compound_nr(head) - 1;
- isolate_hugetlb(head, &source);
+ isolate_hugetlb(folio, &source);
continue;
} else if (PageTransHuge(page))
pfn = page_to_pfn(head) + thp_nr_pages(page) - 1;
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 61aa9aedb728..4e62b26539c9 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -601,7 +601,7 @@ static int queue_pages_hugetlb(pte_t *pte, unsigned long hmask,
/* With MPOL_MF_MOVE, we migrate only unshared hugepage. */
if (flags & (MPOL_MF_MOVE_ALL) ||
(flags & MPOL_MF_MOVE && page_mapcount(page) == 1)) {
- if (isolate_hugetlb(page, qp->pagelist) &&
+ if (isolate_hugetlb(page_folio(page), qp->pagelist) &&
(flags & MPOL_MF_STRICT))
/*
* Failed to isolate page but allow migrating pages
diff --git a/mm/migrate.c b/mm/migrate.c
index 4aea647a0180..6932b3d5a9dd 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1732,7 +1732,7 @@ static int add_page_for_migration(struct mm_struct *mm, unsigned long addr,

if (PageHuge(page)) {
if (PageHead(page)) {
- err = isolate_hugetlb(page, pagelist);
+ err = isolate_hugetlb(page_folio(page), pagelist);
if (!err)
err = 1;
}
--
2.39.0