2020-07-07 11:49:07

by Alex Shi

[permalink] [raw]
Subject: [PATCH v15 05/21] mm/thp: move lru_add_page_tail func to huge_memory.c

The func is only used in huge_memory.c, defining it in other file with a
CONFIG_TRANSPARENT_HUGEPAGE macro restrict just looks weird.

Let's move it THP. And make it static as Hugh Dickin suggested.

Signed-off-by: Alex Shi <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
include/linux/swap.h | 2 --
mm/huge_memory.c | 30 ++++++++++++++++++++++++++++++
mm/swap.c | 33 ---------------------------------
3 files changed, 30 insertions(+), 35 deletions(-)

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 5b3216ba39a9..2c29399b29a0 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -339,8 +339,6 @@ extern void lru_note_cost(struct lruvec *lruvec, bool file,
unsigned int nr_pages);
extern void lru_note_cost_page(struct page *);
extern void lru_cache_add(struct page *);
-extern void lru_add_page_tail(struct page *page, struct page *page_tail,
- struct lruvec *lruvec, struct list_head *head);
extern void activate_page(struct page *);
extern void mark_page_accessed(struct page *);
extern void lru_add_drain(void);
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 78c84bee7e29..9e050b13f597 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2340,6 +2340,36 @@ static void remap_page(struct page *page)
}
}

+static void lru_add_page_tail(struct page *page, struct page *page_tail,
+ struct lruvec *lruvec, struct list_head *list)
+{
+ VM_BUG_ON_PAGE(!PageHead(page), page);
+ VM_BUG_ON_PAGE(PageCompound(page_tail), page);
+ VM_BUG_ON_PAGE(PageLRU(page_tail), page);
+ lockdep_assert_held(&lruvec_pgdat(lruvec)->lru_lock);
+
+ if (!list)
+ SetPageLRU(page_tail);
+
+ if (likely(PageLRU(page)))
+ list_add_tail(&page_tail->lru, &page->lru);
+ else if (list) {
+ /* page reclaim is reclaiming a huge page */
+ get_page(page_tail);
+ list_add_tail(&page_tail->lru, list);
+ } else {
+ /*
+ * Head page has not yet been counted, as an hpage,
+ * so we must account for each subpage individually.
+ *
+ * Put page_tail on the list at the correct position
+ * so they all end up in order.
+ */
+ add_page_to_lru_list_tail(page_tail, lruvec,
+ page_lru(page_tail));
+ }
+}
+
static void __split_huge_page_tail(struct page *head, int tail,
struct lruvec *lruvec, struct list_head *list)
{
diff --git a/mm/swap.c b/mm/swap.c
index a82efc33411f..7701d855873d 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -933,39 +933,6 @@ void __pagevec_release(struct pagevec *pvec)
}
EXPORT_SYMBOL(__pagevec_release);

-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-/* used by __split_huge_page_refcount() */
-void lru_add_page_tail(struct page *page, struct page *page_tail,
- struct lruvec *lruvec, struct list_head *list)
-{
- VM_BUG_ON_PAGE(!PageHead(page), page);
- VM_BUG_ON_PAGE(PageCompound(page_tail), page);
- VM_BUG_ON_PAGE(PageLRU(page_tail), page);
- lockdep_assert_held(&lruvec_pgdat(lruvec)->lru_lock);
-
- if (!list)
- SetPageLRU(page_tail);
-
- if (likely(PageLRU(page)))
- list_add_tail(&page_tail->lru, &page->lru);
- else if (list) {
- /* page reclaim is reclaiming a huge page */
- get_page(page_tail);
- list_add_tail(&page_tail->lru, list);
- } else {
- /*
- * Head page has not yet been counted, as an hpage,
- * so we must account for each subpage individually.
- *
- * Put page_tail on the list at the correct position
- * so they all end up in order.
- */
- add_page_to_lru_list_tail(page_tail, lruvec,
- page_lru(page_tail));
- }
-}
-#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
-
static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec,
void *arg)
{
--
1.8.3.1


2020-07-07 12:01:40

by Alex Shi

[permalink] [raw]
Subject: Re: [PATCH v15 05/21] mm/thp: move lru_add_page_tail func to huge_memory.c



?? 2020/7/7 ????7:46, Alex Shi д??:
>
> +static void lru_add_page_tail(struct page *page, struct page *page_tail,
> + struct lruvec *lruvec, struct list_head *list)
> +{
> + VM_BUG_ON_PAGE(!PageHead(page), page);
> + VM_BUG_ON_PAGE(PageCompound(page_tail), page);
> + VM_BUG_ON_PAGE(PageLRU(page_tail), page);
> + lockdep_assert_held(&lruvec_pgdat(lruvec)->lru_lock);
> +
> + if (!list)
> + SetPageLRU(page_tail);
> +
> + if (likely(PageLRU(page)))
> + list_add_tail(&page_tail->lru, &page->lru);
> + else if (list) {
> + /* page reclaim is reclaiming a huge page */
> + get_page(page_tail);
> + list_add_tail(&page_tail->lru, list);
> + } else {
> + /*
> + * Head page has not yet been counted, as an hpage,
> + * so we must account for each subpage individually.
> + *
> + * Put page_tail on the list at the correct position
> + * so they all end up in order.
> + */
> + add_page_to_lru_list_tail(page_tail, lruvec,
> + page_lru(page_tail));


I missed some points for this function, since in the call chain:
split_huge_page() to lru_add_page_tail, the head page's lru won't be
set when !PageLRU(head). But the other page_tail are add to lru list here
Is it ok for this situation?

Thanks!
Alex

> + }
> +}

2020-07-09 15:56:16

by Kirill A. Shutemov

[permalink] [raw]
Subject: Re: [PATCH v15 05/21] mm/thp: move lru_add_page_tail func to huge_memory.c

On Tue, Jul 07, 2020 at 08:00:11PM +0800, Alex Shi wrote:
>
>
> 在 2020/7/7 下午7:46, Alex Shi 写道:
> >
> > +static void lru_add_page_tail(struct page *page, struct page *page_tail,
> > + struct lruvec *lruvec, struct list_head *list)
> > +{
> > + VM_BUG_ON_PAGE(!PageHead(page), page);
> > + VM_BUG_ON_PAGE(PageCompound(page_tail), page);
> > + VM_BUG_ON_PAGE(PageLRU(page_tail), page);
> > + lockdep_assert_held(&lruvec_pgdat(lruvec)->lru_lock);
> > +
> > + if (!list)
> > + SetPageLRU(page_tail);
> > +
> > + if (likely(PageLRU(page)))
> > + list_add_tail(&page_tail->lru, &page->lru);
> > + else if (list) {
> > + /* page reclaim is reclaiming a huge page */
> > + get_page(page_tail);
> > + list_add_tail(&page_tail->lru, list);
> > + } else {
> > + /*
> > + * Head page has not yet been counted, as an hpage,
> > + * so we must account for each subpage individually.
> > + *
> > + * Put page_tail on the list at the correct position
> > + * so they all end up in order.
> > + */
> > + add_page_to_lru_list_tail(page_tail, lruvec,
> > + page_lru(page_tail));
>
>
> I missed some points for this function, since in the call chain:
> split_huge_page() to lru_add_page_tail, the head page's lru won't be
> set when !PageLRU(head). But the other page_tail are add to lru list here
> Is it ok for this situation?

It doesn't differ from the situation when some pages are isolated from
LRU. Tail page has become completely on its own after
__split_huge_page_tail() has completed, it's not tied to the head page.

--
Kirill A. Shutemov