The patch titled
Subject: mm: unmap VM_PFNMAP mappings with optimized path
has been added to the -mm tree. Its filename is
mm-unmap-vm_pfnmap-mappings-with-optimized-path.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-unmap-vm_pfnmap-mappings-with-optimized-path.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-unmap-vm_pfnmap-mappings-with-optimized-path.patch
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------------------------------------------------------
From: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
Subject: mm: unmap VM_PFNMAP mappings with optimized path
When unmapping VM_PFNMAP mappings, vm flags need to be updated. Since the
vmas have been detached, so it sounds safe to update vm flags with read
mmap_sem.
Link: http://lkml.kernel.org/r/1537376621-51150-4-git-send-email-yang.shi@xxxxxxxxxxxxxxxxx
Signed-off-by: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
Reviewed-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mmap.c | 9 ---------
1 file changed, 9 deletions(-)
--- a/mm/mmap.c~mm-unmap-vm_pfnmap-mappings-with-optimized-path
+++ a/mm/mmap.c
@@ -2771,15 +2771,6 @@ static int __do_munmap(struct mm_struct
munlock_vma_pages_all(tmp);
}
- /*
- * Unmapping vmas, which have VM_HUGETLB or VM_PFNMAP,
- * need get done with write mmap_sem held since they may
- * update vm_flags.
- */
- if (downgrade &&
- (tmp->vm_flags & VM_PFNMAP))
- downgrade = false;
-
tmp = tmp->vm_next;
}
}
_
Patches currently in -mm which might be from yang.shi@xxxxxxxxxxxxxxxxx are
mm-mmap-zap-pages-with-read-mmap_sem-in-munmap.patch
mm-unmap-vm_hugetlb-mappings-with-optimized-path.patch
mm-unmap-vm_pfnmap-mappings-with-optimized-path.patch
