From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk1-f197.google.com (mail-qk1-f197.google.com [209.85.222.197]) by kanga.kvack.org (Postfix) with ESMTP id 6A58D8E0038 for ; Tue, 8 Jan 2019 21:02:10 -0500 (EST) Received: by mail-qk1-f197.google.com with SMTP id y27so4866200qkj.21 for ; Tue, 08 Jan 2019 18:02:10 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id u11si3629933qvl.90.2019.01.08.18.02.09 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 08 Jan 2019 18:02:09 -0800 (PST) From: Andrea Arcangeli Subject: [PATCH 0/1] mm/hugetlb.c: teach follow_hugetlb_page() to handle FOLL_NOWAIT Date: Tue, 8 Jan 2019 21:02:02 -0500 Message-Id: <20190109020203.26669-1-aarcange@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Mike Rapoport , Mike Kravetz , Peter Xu , "Dr. David Alan Gilbert" Hello, this fixes a regression that resurfaced in hugetlbfs code after we fixed it for the core VM a few months ago. This is only reproducible doing postcopy live migration of KVM (the only user of FOLL_NOWAIT) if backed by hugetlbfs memory. It's unrelated to userfaultfd, but userfaultfd reproduces it easily because it's an heavy user of VM_FAULT_RETRY retvals. Thanks, Andrea Andrea Arcangeli (1): mm/hugetlb.c: teach follow_hugetlb_page() to handle FOLL_NOWAIT mm/hugetlb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)