From: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx> Subject: mm/mmap: leave adjust_next as virtual address instead of page frame number Instead of converting adjust_next between bytes and pages number, let's just store the virtual address into adjust_next. Also, this patch fixes one typo in the comment of vma_adjust_trans_huge(). [vbabka@xxxxxxx: changelog tweak] Link: http://lkml.kernel.org/r/20200828081031.11306-1-richard.weiyang@xxxxxxxxxxxxxxxxx Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/huge_memory.c | 4 ++-- mm/mmap.c | 8 ++++---- 2 files changed, 6 insertions(+), 6 deletions(-) --- a/mm/huge_memory.c~mm-mmap-leave-adjust_next-as-virtual-address-instead-of-page-frame-number +++ a/mm/huge_memory.c @@ -2306,13 +2306,13 @@ void vma_adjust_trans_huge(struct vm_are /* * If we're also updating the vma->vm_next->vm_start, if the new - * vm_next->vm_start isn't page aligned and it could previously + * vm_next->vm_start isn't hpage aligned and it could previously * contain an hugepage: check if we need to split an huge pmd. */ if (adjust_next > 0) { struct vm_area_struct *next = vma->vm_next; unsigned long nstart = next->vm_start; - nstart += adjust_next << PAGE_SHIFT; + nstart += adjust_next; if (nstart & ~HPAGE_PMD_MASK && (nstart & HPAGE_PMD_MASK) >= next->vm_start && (nstart & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE <= next->vm_end) --- a/mm/mmap.c~mm-mmap-leave-adjust_next-as-virtual-address-instead-of-page-frame-number +++ a/mm/mmap.c @@ -758,7 +758,7 @@ int __vma_adjust(struct vm_area_struct * * vma expands, overlapping part of the next: * mprotect case 5 shifting the boundary up. */ - adjust_next = (end - next->vm_start) >> PAGE_SHIFT; + adjust_next = (end - next->vm_start); exporter = next; importer = vma; VM_WARN_ON(expand != importer); @@ -768,7 +768,7 @@ int __vma_adjust(struct vm_area_struct * * split_vma inserting another: so it must be * mprotect case 4 shifting the boundary down. */ - adjust_next = -((vma->vm_end - end) >> PAGE_SHIFT); + adjust_next = -(vma->vm_end - end); exporter = vma; importer = next; VM_WARN_ON(expand != importer); @@ -840,8 +840,8 @@ again: } vma->vm_pgoff = pgoff; if (adjust_next) { - next->vm_start += adjust_next << PAGE_SHIFT; - next->vm_pgoff += adjust_next; + next->vm_start += adjust_next; + next->vm_pgoff += adjust_next >> PAGE_SHIFT; } if (root) { _
