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| author | David Hildenbrand <david@redhat.com> | 2023-12-20 23:44:29 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-12-29 11:58:48 -0800 |
| commit | 0c2ec32bf0b2f0d7ccb98c53ee5d255d68e73595 (patch) | |
| tree | 0c59e12d15cb796b80755874b694e29a2f735d5e /mm/rmap.c | |
| parent | ebe2e35ec0f256372c158a18de459fb60070b313 (diff) | |
| download | linux-0c2ec32bf0b2f0d7ccb98c53ee5d255d68e73595.tar.gz linux-0c2ec32bf0b2f0d7ccb98c53ee5d255d68e73595.tar.bz2 linux-0c2ec32bf0b2f0d7ccb98c53ee5d255d68e73595.zip | |
mm/rmap: introduce and use hugetlb_try_share_anon_rmap()
hugetlb rmap handling differs quite a lot from "ordinary" rmap code. For
example, hugetlb currently only supports entire mappings, and treats any
mapping as mapped using a single "logical PTE". Let's move it out of the
way so we can overhaul our "ordinary" rmap. implementation/interface.
So let's introduce and use hugetlb_try_dup_anon_rmap() to make all hugetlb
handling use dedicated hugetlb_* rmap functions.
Add sanity checks that we end up with the right folios in the right
functions.
Note that try_to_unmap_one() does not need care. Easy to spot because
among all that nasty hugetlb special-casing in that function, we're not
using set_huge_pte_at() on the anon path -- well, and that code assumes
that we would want to swapout.
Link: https://lkml.kernel.org/r/20231220224504.646757-6-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/rmap.c')
| -rw-r--r-- | mm/rmap.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index a57ec926daf0..c229e48cf5a9 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -2149,13 +2149,18 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma, !anon_exclusive, subpage); /* See page_try_share_anon_rmap(): clear PTE first. */ - if (anon_exclusive && - page_try_share_anon_rmap(subpage)) { - if (folio_test_hugetlb(folio)) + if (folio_test_hugetlb(folio)) { + if (anon_exclusive && + hugetlb_try_share_anon_rmap(folio)) { set_huge_pte_at(mm, address, pvmw.pte, pteval, hsz); - else - set_pte_at(mm, address, pvmw.pte, pteval); + ret = false; + page_vma_mapped_walk_done(&pvmw); + break; + } + } else if (anon_exclusive && + page_try_share_anon_rmap(subpage)) { + set_pte_at(mm, address, pvmw.pte, pteval); ret = false; page_vma_mapped_walk_done(&pvmw); break; |