Patch "xen/gntdev: Grant maps should not be subject to NUMA balancing" has been added to the 4.3-stable tree

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 4.3-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-4.3 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Boris Ostrovsky <[email protected]>
Date: Tue, 10 Nov 2015 15:10:33 -0500
Subject: xen/gntdev: Grant maps should not be subject to NUMA balancing

From: Boris Ostrovsky <[email protected]>

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.

---
 drivers/xen/gntdev.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -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;

Patches currently in stable-queue which might be from [email protected] are

queue-4.3/x86-xen-don-t-reset-vcpu_info-on-a-cancelled-suspend.patch queue-4.3/x86-paravirt-prevent-rtc_cmos-platform-device-init-on-pv-guests.patch queue-4.3/xen-gntdev-grant-maps-should-not-be-subject-to-numa-balancing.patch