Messages in this thread | | | Subject | Re: [v11 PATCH 3/3] mm: unmap VM_PFNMAP mappings with optimized path | From | Vlastimil Babka <> | Date | Wed, 26 Sep 2018 13:11:45 +0200 |
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On 9/19/18 7:03 PM, Yang Shi wrote: > 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. > > Cc: Michal Hocko <mhocko@kernel.org> > Cc: Vlastimil Babka <vbabka@suse.cz> > Reviewed-by: Matthew Wilcox <willy@infradead.org> > Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> > --- > mm/mmap.c | 9 --------- > 1 file changed, 9 deletions(-) > > diff --git a/mm/mmap.c b/mm/mmap.c > index 490340e..847a17d 100644 > --- a/mm/mmap.c > +++ b/mm/mmap.c > @@ -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,
Ah, the comment should have been already updated with the previous patch. But nevermind as that all goes away.
Acked-by: Vlastimil Babka <vbabka@suse.cz>
> - * 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; > } > } >
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