6.1-stable review patch. If anyone has any objections, please let me know.
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From: Vishal Moola (Oracle) vishal.moola@gmail.com
[ Upstream commit 4a64981dfee9119aa2c1f243b48f34cbbd67779c ]
Replace migrate_page_add() with migrate_folio_add(). migrate_folio_add() does the same a migrate_page_add() but takes in a folio instead of a page. This removes a couple of calls to compound_head().
Link: https://lkml.kernel.org/r/20230130201833.27042-7-vishal.moola@gmail.com Signed-off-by: Vishal Moola (Oracle) vishal.moola@gmail.com Reviewed-by: Yin Fengwei fengwei.yin@intel.com Cc: David Hildenbrand david@redhat.com Cc: Jane Chu jane.chu@oracle.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Stable-dep-of: 24526268f4e3 ("mm: mempolicy: keep VMA walk if both MPOL_MF_STRICT and MPOL_MF_MOVE are specified") Signed-off-by: Sasha Levin sashal@kernel.org --- mm/mempolicy.c | 39 ++++++++++++++++++++------------------- 1 file changed, 20 insertions(+), 19 deletions(-)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 2ae6c8f18aba1..158b0bcd12fd7 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -414,7 +414,7 @@ static const struct mempolicy_operations mpol_ops[MPOL_MAX] = { }, };
-static int migrate_page_add(struct page *page, struct list_head *pagelist, +static int migrate_folio_add(struct folio *folio, struct list_head *foliolist, unsigned long flags);
struct queue_pages { @@ -476,7 +476,7 @@ static int queue_folios_pmd(pmd_t *pmd, spinlock_t *ptl, unsigned long addr, /* go to folio migration */ if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) { if (!vma_migratable(walk->vma) || - migrate_page_add(&folio->page, qp->pagelist, flags)) { + migrate_folio_add(folio, qp->pagelist, flags)) { ret = 1; goto unlock; } @@ -544,7 +544,7 @@ static int queue_folios_pte_range(pmd_t *pmd, unsigned long addr, * temporary off LRU pages in the range. Still * need migrate other LRU pages. */ - if (migrate_page_add(&folio->page, qp->pagelist, flags)) + if (migrate_folio_add(folio, qp->pagelist, flags)) has_unmovable = true; } else break; @@ -1012,27 +1012,28 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask, }
#ifdef CONFIG_MIGRATION -/* - * page migration, thp tail pages can be passed. - */ -static int migrate_page_add(struct page *page, struct list_head *pagelist, +static int migrate_folio_add(struct folio *folio, struct list_head *foliolist, unsigned long flags) { - struct page *head = compound_head(page); /* - * Avoid migrating a page that is shared with others. + * 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) || page_mapcount(head) == 1) { - if (!isolate_lru_page(head)) { - list_add_tail(&head->lru, pagelist); - mod_node_page_state(page_pgdat(head), - NR_ISOLATED_ANON + page_is_file_lru(head), - thp_nr_pages(head)); + if ((flags & MPOL_MF_MOVE_ALL) || folio_estimated_sharers(folio) == 1) { + if (!folio_isolate_lru(folio)) { + list_add_tail(&folio->lru, foliolist); + node_stat_mod_folio(folio, + NR_ISOLATED_ANON + folio_is_file_lru(folio), + folio_nr_pages(folio)); } else if (flags & MPOL_MF_STRICT) { /* - * Non-movable page may reach here. And, there may be - * temporary off LRU pages or non-LRU movable pages. - * Treat them as unmovable pages since they can't be + * Non-movable folio may reach here. And, there may be + * temporary off LRU folios or non-LRU movable folios. + * Treat them as unmovable folios since they can't be * isolated, so they can't be moved at the moment. It * should return -EIO for this case too. */ @@ -1224,7 +1225,7 @@ static struct page *new_page(struct page *page, unsigned long start) } #else
-static int migrate_page_add(struct page *page, struct list_head *pagelist, +static int migrate_folio_add(struct folio *folio, struct list_head *foliolist, unsigned long flags) { return -EIO;