It is now an invariant that VMA_IO_BIT is not set by mm-managed mappings, so each existing VMA_SPECIAL_FLAGS test need only test for VMA_DONTEXPAND_BIT, VMA_PFNMAP_BIT and VMA_MIXEDMAP_BIT.
This is precisely a test for a fixed or non-mm-managed mapping. Update a number of callsites which already explicitly handle hugetlb mappings. vma_supports_mlock(), ksm_compatible() and should_skip_vma() explicitly check for non-mm-managed or fixed mappings, i.e. for !vma_is_mm_backed(), with hugetlb having already been excluded separately. So update those to check for mm-backed (and add comments for the retained droppable checks). No functional change intended. Reviewed-by: Zi Yan <[email protected]> Acked-by: David Hildenbrand (Arm) <[email protected]> Signed-off-by: Lorenzo Stoakes (ARM) <[email protected]> --- mm/internal.h | 3 ++- mm/ksm.c | 5 +++-- mm/vmscan.c | 2 +- 3 files changed, 6 insertions(+), 4 deletions(-) diff --git a/mm/internal.h b/mm/internal.h index b5f7be8f65d8..03f2bb4c30b7 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -1112,8 +1112,9 @@ static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf, static inline bool vma_supports_mlock(const struct vm_area_struct *vma) { - if (vma_test_any_mask(vma, VMA_SPECIAL_FLAGS)) + if (!vma_is_mm_backed(vma)) return false; + /* Core mm may discard droppable memory at any time. */ if (vma_test_single_mask(vma, VMA_DROPPABLE)) return false; if (vma_is_dax(vma) || vma_is_hugetlb(vma)) diff --git a/mm/ksm.c b/mm/ksm.c index 624f37975e12..df4c5199f625 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -747,9 +747,10 @@ static bool ksm_compatible(const struct file *file, vma_flags_t vma_flags) if (vma_flags_test_any(&vma_flags, VMA_SHARED_BIT, VMA_MAYSHARE_BIT, VMA_HUGETLB_BIT)) return false; - if (vma_flags_test_single_mask(&vma_flags, VMA_DROPPABLE)) + if (!vma_flags_is_mm_backed(&vma_flags)) return false; - if (vma_flags_test_any_mask(&vma_flags, VMA_SPECIAL_FLAGS)) + /* Core mm may discard droppable memory at any time. */ + if (vma_flags_test_single_mask(&vma_flags, VMA_DROPPABLE)) return false; if (file_is_dax(file)) return false; diff --git a/mm/vmscan.c b/mm/vmscan.c index 12ed3388ee41..aecb157bc379 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3477,7 +3477,7 @@ static int should_skip_vma(unsigned long start, unsigned long end, struct mm_wal if (!vma_has_recency(vma)) return true; - if (vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) + if (vma_test(vma, VMA_LOCKED_BIT) || !vma_is_mm_backed(vma)) return true; if (vma == get_gate_vma(vma->vm_mm)) -- 2.55.0
