diff options
| author | David Hildenbrand <david@redhat.com> | 2022-05-09 18:20:44 -0700 |
|---|---|---|
| committer | akpm <akpm@linux-foundation.org> | 2022-05-09 18:20:44 -0700 |
| commit | 7f5abe609b3dcbc62a36e18b1437f4f3521ecb75 (patch) | |
| tree | 37cb472bda88c5b0d11248ea5f66564fc332a4c6 /mm | |
| parent | 6c287605fd56466e645693eff3ae7c08fba56e0a (diff) | |
| download | lwn-7f5abe609b3dcbc62a36e18b1437f4f3521ecb75.tar.gz lwn-7f5abe609b3dcbc62a36e18b1437f4f3521ecb75.zip | |
mm/rmap: fail try_to_migrate() early when setting a PMD migration entry fails
Let's fail right away in case we cannot clear PG_anon_exclusive because
the anon THP may be pinned. Right now, we continue trying to install
migration entries and the caller of try_to_migrate() will realize that the
page is still mapped and has to restore the migration entries. Let's just
fail fast just like for PTE migration entries.
Link: https://lkml.kernel.org/r/20220428083441.37290-14-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Don Dutile <ddutile@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Liang Zhang <zhangliang5@huawei.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Oded Gabbay <oded.gabbay@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pedro Demarchi Gomes <pedrodemargomes@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/huge_memory.c | 8 | ||||
| -rw-r--r-- | mm/rmap.c | 6 |
2 files changed, 10 insertions, 4 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 231911b7bf9d..14d7fa6dc793 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -3066,7 +3066,7 @@ late_initcall(split_huge_pages_debugfs); #endif #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION -void set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, +int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, struct page *page) { struct vm_area_struct *vma = pvmw->vma; @@ -3078,7 +3078,7 @@ void set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, pmd_t pmdswp; if (!(pvmw->pmd && !pvmw->pte)) - return; + return 0; flush_cache_range(vma, address, address + HPAGE_PMD_SIZE); pmdval = pmdp_invalidate(vma, address, pvmw->pmd); @@ -3086,7 +3086,7 @@ void set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, anon_exclusive = PageAnon(page) && PageAnonExclusive(page); if (anon_exclusive && page_try_share_anon_rmap(page)) { set_pmd_at(mm, address, pvmw->pmd, pmdval); - return; + return -EBUSY; } if (pmd_dirty(pmdval)) @@ -3104,6 +3104,8 @@ void set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, page_remove_rmap(page, vma, true); put_page(page); trace_set_migration_pmd(address, pmd_val(pmdswp)); + + return 0; } void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, struct page *new) diff --git a/mm/rmap.c b/mm/rmap.c index 0d63e7ce35cc..f96cc7eb23ec 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1856,7 +1856,11 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma, VM_BUG_ON_FOLIO(folio_test_hugetlb(folio) || !folio_test_pmd_mappable(folio), folio); - set_pmd_migration_entry(&pvmw, subpage); + if (set_pmd_migration_entry(&pvmw, subpage)) { + ret = false; + page_vma_mapped_walk_done(&pvmw); + break; + } continue; } #endif |