| From 9c17d96500f78d7ecdb71ca6942830158bc75a2b Mon Sep 17 00:00:00 2001 |
| From: Boris Ostrovsky <boris.ostrovsky@oracle.com> |
| Date: Tue, 10 Nov 2015 15:10:33 -0500 |
| Subject: xen/gntdev: Grant maps should not be subject to NUMA balancing |
| |
| From: Boris Ostrovsky <boris.ostrovsky@oracle.com> |
| |
| commit 9c17d96500f78d7ecdb71ca6942830158bc75a2b upstream. |
| |
| 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> |
| Signed-off-by: David Vrabel <david.vrabel@citrix.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/xen/gntdev.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/drivers/xen/gntdev.c |
| +++ b/drivers/xen/gntdev.c |
| @@ -804,7 +804,7 @@ static int gntdev_mmap(struct file *flip |
| |
| 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; |
