From 0a2c1e8183163a31fe8c9838f3108aacf9c05c4a Mon Sep 17 00:00:00 2001 From: "Vishal Moola (Oracle)" Date: Mon, 30 Jan 2023 12:18:31 -0800 Subject: [PATCH] mm/mempolicy: convert queue_pages_hugetlb() to queue_folios_hugetlb() This change is in preparation for the conversion of queue_pages_required() to queue_folio_required() and migrate_page_add() to migrate_folio_add(). Link: https://lkml.kernel.org/r/20230130201833.27042-5-vishal.moola@gmail.com Signed-off-by: Vishal Moola (Oracle) Cc: David Hildenbrand Cc: Jane Chu Cc: "Yin, Fengwei" Signed-off-by: Andrew Morton --- mm/mempolicy.c | 29 ++++++++++++++++++----------- 1 file changed, 18 insertions(+), 11 deletions(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index b0805bb87655..668392493500 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -558,7 +558,7 @@ static int queue_folios_pte_range(pmd_t *pmd, unsigned long addr, return addr != end ? -EIO : 0; } -static int queue_pages_hugetlb(pte_t *pte, unsigned long hmask, +static int queue_folios_hugetlb(pte_t *pte, unsigned long hmask, unsigned long addr, unsigned long end, struct mm_walk *walk) { @@ -566,7 +566,7 @@ static int queue_pages_hugetlb(pte_t *pte, unsigned long hmask, #ifdef CONFIG_HUGETLB_PAGE struct queue_pages *qp = walk->private; unsigned long flags = (qp->flags & MPOL_MF_VALID); - struct page *page; + struct folio *folio; spinlock_t *ptl; pte_t entry; @@ -574,13 +574,13 @@ static int queue_pages_hugetlb(pte_t *pte, unsigned long hmask, entry = huge_ptep_get(pte); if (!pte_present(entry)) goto unlock; - page = pte_page(entry); - if (!queue_pages_required(page, qp)) + folio = pfn_folio(pte_pfn(entry)); + if (!queue_pages_required(&folio->page, qp)) goto unlock; if (flags == MPOL_MF_STRICT) { /* - * STRICT alone means only detecting misplaced page and no + * STRICT alone means only detecting misplaced folio and no * need to further check other vma. */ ret = -EIO; @@ -591,21 +591,28 @@ static int queue_pages_hugetlb(pte_t *pte, unsigned long hmask, /* * Must be STRICT with MOVE*, otherwise .test_walk() have * stopped walking current vma. - * Detecting misplaced page but allow migrating pages which + * Detecting misplaced folio but allow migrating folios which * have been queued. */ ret = 1; goto unlock; } - /* With MPOL_MF_MOVE, we migrate only unshared hugepage. */ + /* + * With MPOL_MF_MOVE, we try to migrate only unshared folios. If it + * is shared it is likely not worth migrating. + * + * To check if the folio is shared, ideally we want to make sure + * every page is mapped to the same process. Doing that is very + * expensive, so check the estimated mapcount of the folio instead. + */ if (flags & (MPOL_MF_MOVE_ALL) || - (flags & MPOL_MF_MOVE && page_mapcount(page) == 1 && + (flags & MPOL_MF_MOVE && folio_estimated_sharers(folio) == 1 && !hugetlb_pmd_shared(pte))) { - if (isolate_hugetlb(page_folio(page), qp->pagelist) && + if (isolate_hugetlb(folio, qp->pagelist) && (flags & MPOL_MF_STRICT)) /* - * Failed to isolate page but allow migrating pages + * Failed to isolate folio but allow migrating pages * which have been queued. */ ret = 1; @@ -703,7 +710,7 @@ static int queue_pages_test_walk(unsigned long start, unsigned long end, } static const struct mm_walk_ops queue_pages_walk_ops = { - .hugetlb_entry = queue_pages_hugetlb, + .hugetlb_entry = queue_folios_hugetlb, .pmd_entry = queue_folios_pte_range, .test_walk = queue_pages_test_walk, }; -- 2.25.1