xen/gntdev: Grant maps should not be subject to NUMA balancing

Doing so will cause the grant to be unmapped and then, during
fault handling, the fault to be mistakenly treated as NUMA hint
fault.

In addition, even if those maps could partcipate in NUMA
balancing, it wouldn't provide any benefit since we are unable
to determine physical page's node (even if/when VNUMA is
implemented).

Marking grant maps' VMAs as VM_IO will exclude them from being
part of NUMA balancing.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
This commit is contained in:
Boris Ostrovsky 2015-11-10 15:10:33 -05:00 committed by David Vrabel
parent abed7d0710
commit 9c17d96500

View file

@ -804,7 +804,7 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
vma->vm_ops = &gntdev_vmops;
vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP | VM_IO;
if (use_ptemod)
vma->vm_flags |= VM_DONTCOPY;