mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-28 14:44:10 +08:00
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@linux.alibaba.com Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> Reviewed-by: Matthew Wilcox <willy@infradead.org> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
b4cefb3605
commit
cb4922496a
@ -2771,15 +2771,6 @@ static int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
|
||||
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;
|
||||
}
|
||||
}
|
||||
|
Loading…
Reference in New Issue
Block a user