From: Boris Ostrovsky Date: Tue, 10 Nov 2015 15:10:33 -0500 Subject: xen/gntdev: Grant maps should not be subject to NUMA balancing Origin: https://git.kernel.org/linus/9c17d96500f78d7ecdb71ca6942830158bc75a2b Bug-Debian: https://bugs.debian.org/810472 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 Cc: stable@vger.kernel.org Signed-off-by: David Vrabel --- drivers/xen/gntdev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 2ea0b3b..1be5dd0 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -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;