From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:50976 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760651AbdADOBg (ORCPT ); Wed, 4 Jan 2017 09:01:36 -0500 Subject: Patch "xen/gntdev: Use VM_MIXEDMAP instead of VM_IO to avoid NUMA balancing" has been added to the 4.9-stable tree To: boris.ostrovsky@oracle.com, gregkh@linuxfoundation.org, hughd@google.com, jgross@suse.com, olaf@aepfle.de Cc: , From: Date: Wed, 04 Jan 2017 15:00:27 +0100 Message-ID: <1483538427131203@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled xen/gntdev: Use VM_MIXEDMAP instead of VM_IO to avoid NUMA balancing to the 4.9-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-use-vm_mixedmap-instead-of-vm_io-to-avoid-numa-balancing.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 30faaafdfa0c754c91bac60f216c9f34a2bfdf7e Mon Sep 17 00:00:00 2001 From: Boris Ostrovsky Date: Mon, 21 Nov 2016 09:56:06 -0500 Subject: xen/gntdev: Use VM_MIXEDMAP instead of VM_IO to avoid NUMA balancing From: Boris Ostrovsky commit 30faaafdfa0c754c91bac60f216c9f34a2bfdf7e upstream. Commit 9c17d96500f7 ("xen/gntdev: Grant maps should not be subject to NUMA balancing") set VM_IO flag to prevent grant maps from being subjected to NUMA balancing. It was discovered recently that this flag causes get_user_pages() to always fail with -EFAULT. check_vma_flags __get_user_pages __get_user_pages_locked __get_user_pages_unlocked get_user_pages_fast iov_iter_get_pages dio_refill_pages do_direct_IO do_blockdev_direct_IO do_blockdev_direct_IO ext4_direct_IO_read generic_file_read_iter aio_run_iocb (which can happen if guest's vdisk has direct-io-safe option). To avoid this let's use VM_MIXEDMAP flag instead --- it prevents NUMA balancing just as VM_IO does and has no effect on check_vma_flags(). Reported-by: Olaf Hering Suggested-by: Hugh Dickins Signed-off-by: Boris Ostrovsky Acked-by: Hugh Dickins Tested-by: Olaf Hering Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman --- drivers/xen/gntdev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -1007,7 +1007,7 @@ static int gntdev_mmap(struct file *flip vma->vm_ops = &gntdev_vmops; - vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP | VM_IO; + vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP | VM_MIXEDMAP; if (use_ptemod) vma->vm_flags |= VM_DONTCOPY; Patches currently in stable-queue which might be from boris.ostrovsky@oracle.com are queue-4.9/xen-gntdev-use-vm_mixedmap-instead-of-vm_io-to-avoid-numa-balancing.patch