From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2C13CC433EF for ; Thu, 9 Sep 2021 11:37:38 +0000 (UTC) Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C01A4610E9 for ; Thu, 9 Sep 2021 11:37:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org C01A4610E9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=oss.oracle.com Received: from pps.filterd (m0246629.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 1899YLd4010974; Thu, 9 Sep 2021 11:37:37 GMT Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by mx0b-00069f02.pphosted.com with ESMTP id 3ayfrpr9bw-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 09 Sep 2021 11:37:37 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 189BUrOY098206; Thu, 9 Sep 2021 11:37:35 GMT Received: from oss.oracle.com (oss-old-reserved.oracle.com [137.254.22.2]) by userp3030.oracle.com with ESMTP id 3axcq2tygm-1 (version=TLSv1 cipher=AES256-SHA bits=256 verify=NO); Thu, 09 Sep 2021 11:37:35 +0000 Received: from localhost ([127.0.0.1] helo=lb-oss.oracle.com) by oss.oracle.com with esmtp (Exim 4.63) (envelope-from ) id 1mOIN4-0003tr-NV; Thu, 09 Sep 2021 04:37:34 -0700 Received: from aserp3030.oracle.com ([141.146.126.71]) by oss.oracle.com with esmtp (Exim 4.63) (envelope-from ) id 1mOIN2-0003tb-Eg for ocfs2-devel@oss.oracle.com; Thu, 09 Sep 2021 04:37:32 -0700 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 189BUHdk187429 for ; Thu, 9 Sep 2021 11:37:32 GMT Received: from mx0a-00069f01.pphosted.com (mx0a-00069f01.pphosted.com [205.220.165.26]) by aserp3030.oracle.com with ESMTP id 3axcpq39pu-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Thu, 09 Sep 2021 11:37:32 +0000 Received: from pps.filterd (m0246573.ppops.net [127.0.0.1]) by mx0b-00069f01.pphosted.com (8.16.1.2/8.16.0.43) with SMTP id 1899TDXu024238 for ; Thu, 9 Sep 2021 11:37:31 GMT Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by mx0b-00069f01.pphosted.com with ESMTP id 3ay9kgwbss-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO) for ; Thu, 09 Sep 2021 11:37:30 +0000 Received: from hch by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mOILm-009lu0-R5; Thu, 09 Sep 2021 11:36:19 +0000 Date: Thu, 9 Sep 2021 12:36:14 +0100 From: Christoph Hellwig To: Andreas Gruenbacher Message-ID: References: <20210827164926.1726765-1-agruenba@redhat.com> <20210827164926.1726765-18-agruenba@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210827164926.1726765-18-agruenba@redhat.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html X-Source-IP: 90.155.50.34 X-ServerName: casper.infradead.org X-Proofpoint-SPF-Result: None X-Proofpoint-Virus-Version: vendor=nai engine=6300 definitions=10101 signatures=668682 X-Proofpoint-Spam-Details: rule=tap_notspam policy=tap score=0 impostorscore=0 mlxscore=0 lowpriorityscore=0 priorityscore=353 spamscore=0 suspectscore=0 adultscore=0 phishscore=0 malwarescore=0 clxscore=304 mlxlogscore=555 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2109030001 definitions=main-2109090070 X-Spam: Clean Cc: cluster-devel@redhat.com, Jan Kara , linux-kernel@vger.kernel.org, Christoph Hellwig , Alexander Viro , linux-fsdevel@vger.kernel.org, Linus Torvalds , ocfs2-devel@oss.oracle.com Subject: Re: [Ocfs2-devel] [PATCH v7 17/19] gup: Introduce FOLL_NOFAULT flag to disable page faults X-BeenThere: ocfs2-devel@oss.oracle.com X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: ocfs2-devel-bounces@oss.oracle.com Errors-To: ocfs2-devel-bounces@oss.oracle.com X-Proofpoint-Virus-Version: vendor=nai engine=6300 definitions=10101 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 adultscore=0 malwarescore=0 mlxscore=0 spamscore=0 bulkscore=0 mlxlogscore=999 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2109030001 definitions=main-2109090070 X-Proofpoint-GUID: n0x66J4vPRWprNnGyqmrLxBTVpqzpS2X X-Proofpoint-ORIG-GUID: n0x66J4vPRWprNnGyqmrLxBTVpqzpS2X On Fri, Aug 27, 2021 at 06:49:24PM +0200, Andreas Gruenbacher wrote: > Introduce a new FOLL_NOFAULT flag that causes get_user_pages to return > -EFAULT when it would otherwise trigger a page fault. This is roughly > similar to FOLL_FAST_ONLY but available on all architectures, and less > fragile. So, FOLL_FAST_ONLY only has one single user through get_user_pages_fast_only (pin_user_pages_fast_only is entirely unused, which makes totally sense given that give up on fault and pin are not exactly useful semantics). But it looks like they want to call it from atomic context, so we can't really share it. Sight, I hate all these single-user FOLL flags that make gup.c a complete mess. But otherwise this looks fine. _______________________________________________ Ocfs2-devel mailing list Ocfs2-devel@oss.oracle.com https://oss.oracle.com/mailman/listinfo/ocfs2-devel