Patch "xen/gntdev: Grant maps should not be subject to NUMA balancing" has been added to the 3.10-stable tree

Patch "xen/gntdev: Grant maps should not be subject to NUMA balancing" has been added to the 3.10-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

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

to the 3.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     xen-gntdev-grant-maps-should-not-be-subject-to-numa-balancing.patch
and it can be found in the queue-3.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>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
@@ -770,7 +770,7 @@ 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;


Patches currently in stable-queue which might be from boris.ostrovsky@oracle.com are

queue-3.10/x86-xen-don-t-reset-vcpu_info-on-a-cancelled-suspend.patch
queue-3.10/xen-gntdev-grant-maps-should-not-be-subject-to-numa-balancing.patch