From: David Hildenbrand david@redhat.com
mainline inclusion from mainline-v6.8-rc1 commit 5b205c7f2684764c8a9cc3442986623d4d6e87f1 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I9CESE CVE: NA
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Let's convert migrate_vma_collect_pmd(). While at it, perform more folio conversion.
Link: https://lkml.kernel.org/r/20231220224504.646757-30-david@redhat.com Signed-off-by: David Hildenbrand david@redhat.com Cc: Hugh Dickins hughd@google.com Cc: Matthew Wilcox (Oracle) willy@infradead.org Cc: Muchun Song muchun.song@linux.dev Cc: Muchun Song songmuchun@bytedance.com Cc: Peter Xu peterx@redhat.com Cc: Ryan Roberts ryan.roberts@arm.com Cc: Yin Fengwei fengwei.yin@intel.com Signed-off-by: Andrew Morton akpm@linux-foundation.org (cherry picked from commit 5b205c7f2684764c8a9cc3442986623d4d6e87f1) Signed-off-by: Kefeng Wang wangkefeng.wang@huawei.com --- mm/migrate_device.c | 39 +++++++++++++++++++++------------------ 1 file changed, 21 insertions(+), 18 deletions(-)
diff --git a/mm/migrate_device.c b/mm/migrate_device.c index 2e5bce2f1cb9..cee7957cecb8 100644 --- a/mm/migrate_device.c +++ b/mm/migrate_device.c @@ -107,6 +107,7 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp,
for (; addr < end; addr += PAGE_SIZE, ptep++) { unsigned long mpfn = 0, pfn; + struct folio *folio; struct page *page; swp_entry_t entry; pte_t pte; @@ -168,41 +169,43 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp, }
/* - * By getting a reference on the page we pin it and that blocks + * By getting a reference on the folio we pin it and that blocks * any kind of migration. Side effect is that it "freezes" the * pte. * - * We drop this reference after isolating the page from the lru - * for non device page (device page are not on the lru and thus + * We drop this reference after isolating the folio from the lru + * for non device folio (device folio are not on the lru and thus * can't be dropped from it). */ - get_page(page); + folio = page_folio(page); + folio_get(folio);
/* - * We rely on trylock_page() to avoid deadlock between + * We rely on folio_trylock() to avoid deadlock between * concurrent migrations where each is waiting on the others - * page lock. If we can't immediately lock the page we fail this + * folio lock. If we can't immediately lock the folio we fail this * migration as it is only best effort anyway. * - * If we can lock the page it's safe to set up a migration entry - * now. In the common case where the page is mapped once in a + * If we can lock the folio it's safe to set up a migration entry + * now. In the common case where the folio is mapped once in a * single process setting up the migration entry now is an * optimisation to avoid walking the rmap later with * try_to_migrate(). */ - if (trylock_page(page)) { + if (folio_trylock(folio)) { bool anon_exclusive; pte_t swp_pte;
flush_cache_page(vma, addr, pte_pfn(pte)); - anon_exclusive = PageAnon(page) && PageAnonExclusive(page); + anon_exclusive = folio_test_anon(folio) && + PageAnonExclusive(page); if (anon_exclusive) { pte = ptep_clear_flush(vma, addr, ptep);
if (page_try_share_anon_rmap(page)) { set_pte_at(mm, addr, ptep, pte); - unlock_page(page); - put_page(page); + folio_unlock(folio); + folio_put(folio); mpfn = 0; goto next; } @@ -214,7 +217,7 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp,
/* Set the dirty flag on the folio now the pte is gone. */ if (pte_dirty(pte)) - folio_mark_dirty(page_folio(page)); + folio_mark_dirty(folio);
/* Setup special migration page table entry */ if (mpfn & MIGRATE_PFN_WRITE) @@ -248,16 +251,16 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp,
/* * This is like regular unmap: we remove the rmap and - * drop page refcount. Page won't be freed, as we took - * a reference just above. + * drop the folio refcount. The folio won't be freed, as + * we took a reference just above. */ - page_remove_rmap(page, vma, false); - put_page(page); + folio_remove_rmap_pte(folio, page, vma); + folio_put(folio);
if (pte_present(pte)) unmapped++; } else { - put_page(page); + folio_put(folio); mpfn = 0; }