From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f197.google.com (mail-pf0-f197.google.com [209.85.192.197]) by kanga.kvack.org (Postfix) with ESMTP id 73A386B03A5 for ; Tue, 16 May 2017 06:36:16 -0400 (EDT) Received: by mail-pf0-f197.google.com with SMTP id p74so122067687pfd.11 for ; Tue, 16 May 2017 03:36:16 -0700 (PDT) Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com. [148.163.156.1]) by mx.google.com with ESMTPS id d2si13576147pgf.380.2017.05.16.03.36.15 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 16 May 2017 03:36:15 -0700 (PDT) Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v4GAaAjc043540 for ; Tue, 16 May 2017 06:36:15 -0400 Received: from e06smtp11.uk.ibm.com (e06smtp11.uk.ibm.com [195.75.94.107]) by mx0a-001b2d01.pphosted.com with ESMTP id 2afwhj71px-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 16 May 2017 06:36:14 -0400 Received: from localhost by e06smtp11.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 16 May 2017 11:36:12 +0100 From: "Mike Rapoport" Subject: [RFC PATCH 2/5] userfaultfd: introduce userfaultfd_should_wait helper Date: Tue, 16 May 2017 13:35:59 +0300 In-Reply-To: <1494930962-3318-1-git-send-email-rppt@linux.vnet.ibm.com> References: <1494930962-3318-1-git-send-email-rppt@linux.vnet.ibm.com> Message-Id: <1494930962-3318-3-git-send-email-rppt@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrea Arcangeli Cc: Pavel Emelyanov , linux-mm , Mike Rapoport Signed-off-by: Mike Rapoport --- fs/userfaultfd.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index b061e96..fee5f08 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -91,21 +91,31 @@ struct userfaultfd_wake_range { unsigned long len; }; +static bool userfaultfd_should_wake(struct userfaultfd_wait_queue *uwq, + struct userfaultfd_wake_range *range) +{ + unsigned long start, len, address; + + /* len == 0 means wake all */ + address = uwq->msg.arg.pagefault.address; + start = range->start; + len = range->len; + if (len && (start > address || start + len <= address)) + return false; + + return true; +} + static int userfaultfd_wake_function(wait_queue_t *wq, unsigned mode, int wake_flags, void *key) { struct userfaultfd_wake_range *range = key; int ret; struct userfaultfd_wait_queue *uwq; - unsigned long start, len; uwq = container_of(wq, struct userfaultfd_wait_queue, wq); ret = 0; - /* len == 0 means wake all */ - start = range->start; - len = range->len; - if (len && (start > uwq->msg.arg.pagefault.address || - start + len <= uwq->msg.arg.pagefault.address)) + if (!userfaultfd_should_wake(uwq, range)) goto out; WRITE_ONCE(uwq->waken, true); /* -- 2.7.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org