From: Kirill A. Shutemov kirill@shutemov.name
[ Upstream commit 8cce54756806e5777069c46011c5f54f9feac717 ]
File THPs may now be of arbitrary size, and we can't rely on that size after doing the split so remember the number of pages before we start the split.
Signed-off-by: Kirill A. Shutemov kirill@shutemov.name Signed-off-by: Matthew Wilcox (Oracle) willy@infradead.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Reviewed-by: SeongJae Park sjpark@amazon.de Cc: Huang Ying ying.huang@intel.com Link: https://lkml.kernel.org/r/20200908195539.25896-6-willy@infradead.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- mm/huge_memory.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index dbac774103769..d37e205d3eae7 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2335,13 +2335,13 @@ static void unmap_page(struct page *page) VM_BUG_ON_PAGE(!unmap_success, page); }
-static void remap_page(struct page *page) +static void remap_page(struct page *page, unsigned int nr) { int i; if (PageTransHuge(page)) { remove_migration_ptes(page, page, true); } else { - for (i = 0; i < HPAGE_PMD_NR; i++) + for (i = 0; i < nr; i++) remove_migration_ptes(page + i, page + i, true); } } @@ -2416,6 +2416,7 @@ static void __split_huge_page(struct page *page, struct list_head *list, struct lruvec *lruvec; struct address_space *swap_cache = NULL; unsigned long offset = 0; + unsigned int nr = thp_nr_pages(head); int i;
lruvec = mem_cgroup_page_lruvec(head, pgdat); @@ -2431,7 +2432,7 @@ static void __split_huge_page(struct page *page, struct list_head *list, xa_lock(&swap_cache->i_pages); }
- for (i = HPAGE_PMD_NR - 1; i >= 1; i--) { + for (i = nr - 1; i >= 1; i--) { __split_huge_page_tail(head, i, lruvec, list); /* Some pages can be beyond i_size: drop them from page cache */ if (head[i].index >= end) { @@ -2451,7 +2452,7 @@ static void __split_huge_page(struct page *page, struct list_head *list,
ClearPageCompound(head);
- split_page_owner(head, HPAGE_PMD_NR); + split_page_owner(head, nr);
/* See comment in __split_huge_page_tail() */ if (PageAnon(head)) { @@ -2470,9 +2471,9 @@ static void __split_huge_page(struct page *page, struct list_head *list,
spin_unlock_irqrestore(&pgdat->lru_lock, flags);
- remap_page(head); + remap_page(head, nr);
- for (i = 0; i < HPAGE_PMD_NR; i++) { + for (i = 0; i < nr; i++) { struct page *subpage = head + i; if (subpage == page) continue; @@ -2725,7 +2726,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) fail: if (mapping) xa_unlock(&mapping->i_pages); spin_unlock_irqrestore(&pgdata->lru_lock, flags); - remap_page(head); + remap_page(head, thp_nr_pages(head)); ret = -EBUSY; }