From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [PATCH] xen/gntdev: Grant maps should not be subject to NUMA balancing Date: Tue, 10 Nov 2015 14:36:44 -0500 Message-ID: <20151110193644.GA32257@char.us.oracle.com> References: <1447183364-2959-1-git-send-email-boris.ostrovsky@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1447183364-2959-1-git-send-email-boris.ostrovsky@oracle.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Boris Ostrovsky Cc: linux-kernel@vger.kernel.org, david.vrabel@citrix.com, xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On Tue, Nov 10, 2015 at 02:22:44PM -0500, Boris Ostrovsky wrote: > 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 we those maps could partcipate in NUMA > balancing it wouldn't provide any benefit since we wouldn't be > able 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. > Should this be 'cc:stable@vger.kernel.org' ? > Signed-off-by: Boris Ostrovsky > --- > drivers/xen/gntdev.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c > index 67b9163..bf312df 100644 > --- a/drivers/xen/gntdev.c > +++ b/drivers/xen/gntdev.c > @@ -802,7 +802,7 @@ 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; > -- > 1.7.1 >