From patchwork Fri Oct 3 17:07:51 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Andrea Arcangeli X-Patchwork-Id: 396435 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id DD67C14011B for ; Sat, 4 Oct 2014 06:49:56 +1000 (EST) Received: from localhost ([::1]:41219 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xa9nX-0008Bk-2v for incoming@patchwork.ozlabs.org; Fri, 03 Oct 2014 16:49:55 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44828) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xa6Le-0001OF-IX for qemu-devel@nongnu.org; Fri, 03 Oct 2014 13:09:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Xa6LX-0005mH-6m for qemu-devel@nongnu.org; Fri, 03 Oct 2014 13:08:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:31679) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xa6LW-0005mB-Vd for qemu-devel@nongnu.org; Fri, 03 Oct 2014 13:08:47 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s93H8B0g004005 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 3 Oct 2014 13:08:11 -0400 Received: from mail.random (ovpn-116-38.ams2.redhat.com [10.36.116.38]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s93H8710002347 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Fri, 3 Oct 2014 13:08:08 -0400 From: Andrea Arcangeli To: qemu-devel@nongnu.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-api@vger.kernel.org Date: Fri, 3 Oct 2014 19:07:51 +0200 Message-Id: <1412356087-16115-2-git-send-email-aarcange@redhat.com> In-Reply-To: <1412356087-16115-1-git-send-email-aarcange@redhat.com> References: <1412356087-16115-1-git-send-email-aarcange@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-MIME-Autoconverted: from 8bit to quoted-printable by mx1.redhat.com id s93H8B0g004005 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 X-Mailman-Approved-At: Fri, 03 Oct 2014 16:48:55 -0400 Cc: Robert Love , Dave Hansen , Jan Kara , Neil Brown , Stefan Hajnoczi , Andrew Jones , KOSAKI Motohiro , Michel Lespinasse , Taras Glek , Juan Quintela , Hugh Dickins , Isaku Yamahata , Mel Gorman , Sasha Levin , Android Kernel Team , "\\\"Dr. David Alan Gilbert\\\"" , "Huangpeng \(Peter\)" , Andres Lagar-Cavilla , Christopher Covington , Anthony Liguori , Paolo Bonzini , Keith Packard , Wenchao Xia , Andy Lutomirski , Minchan Kim , Dmitry Adamushko , Johannes Weiner , Mike Hommey , Andrew Morton , Linus Torvalds , Peter Feiner Subject: [Qemu-devel] [PATCH 01/17] mm: gup: add FOLL_TRIED X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Andres Lagar-Cavilla Reviewed-by: Radim Krčmář Signed-off-by: Andres Lagar-Cavilla Signed-off-by: Andrea Arcangeli --- include/linux/mm.h | 1 + mm/gup.c | 4 ++++ 2 files changed, 5 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index 8981cc8..0f4196a 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1985,6 +1985,7 @@ static inline struct page *follow_page(struct vm_area_struct *vma, #define FOLL_HWPOISON 0x100 /* check page is hwpoisoned */ #define FOLL_NUMA 0x200 /* force NUMA hinting page fault */ #define FOLL_MIGRATION 0x400 /* wait for page to replace migration entry */ +#define FOLL_TRIED 0x800 /* a retry, previous pass started an IO */ typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr, void *data); diff --git a/mm/gup.c b/mm/gup.c index 91d044b..af7ea3e 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -281,6 +281,10 @@ static int faultin_page(struct task_struct *tsk, struct vm_area_struct *vma, fault_flags |= FAULT_FLAG_ALLOW_RETRY; if (*flags & FOLL_NOWAIT) fault_flags |= FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_RETRY_NOWAIT; + if (*flags & FOLL_TRIED) { + VM_WARN_ON_ONCE(fault_flags & FAULT_FLAG_ALLOW_RETRY); + fault_flags |= FAULT_FLAG_TRIED; + } ret = handle_mm_fault(mm, vma, address, fault_flags); if (ret & VM_FAULT_ERROR) {