Commit 9c17d965 authored Nov 10, 2015 by Boris Ostrovsky Committed by David Vrabel Nov 26, 2015

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>

parent abed7d07

drivers/xen/gntdev.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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;