lkml.org 
[lkml]   [2015]   [Sep]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: LTP regressions due to 6dc296e7df4c ("mm: make sure all file VMAs have ->vm_ops set")
    On 09/14, Oleg Nesterov wrote:
    >
    > On 09/14, Kirill A. Shutemov wrote:
    > >
    > > Fix is below. I don't really like it, but I cannot find any better
    > > solution.
    >
    > Me too...
    >
    > But this change "documents" the nasty special "vm_file && !vm_ops" case, and
    > I am not sure how we can remove it later...
    >
    > So perhaps we should change vma_is_anonymous() back to check ->fault too,
    >
    > static inline bool vma_is_anonymous(struct vm_area_struct *vma)
    > {
    > - return !vma->vm_ops;
    > + return !vma->vm_ops || !vma->vm_ops->fault;
    > }
    >
    > and remove the "vma->vm_file && !vma->vm_ops" checks in mmap_region() paths.
    ^^^

    sorry, I actually meant "or remove". But perhaps "and" makes sense too.

    Say, if we change vma_is_anonymous() as above, then we can kill
    arch_vma_name() on x86. mpx_mmap() can install the dummy vm_ops with
    the single ->name() method.

    > I dunno.

    Yes. Up to you.

    Oleg.



    \
     
     \ /
      Last update: 2015-09-14 20:01    [W:2.197 / U:0.016 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site