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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 53444C43603 for ; Tue, 17 Dec 2019 21:12:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2BB07206E0 for ; Tue, 17 Dec 2019 21:12:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726895AbfLQVMf (ORCPT ); Tue, 17 Dec 2019 16:12:35 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:39864 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726634AbfLQVMf (ORCPT ); Tue, 17 Dec 2019 16:12:35 -0500 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id xBHL8DuS125217; Tue, 17 Dec 2019 16:12:33 -0500 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 2wy1x19xfk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 17 Dec 2019 16:12:33 -0500 Received: from m0098417.ppops.net (m0098417.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id xBHLA3nc131895; Tue, 17 Dec 2019 16:12:33 -0500 Received: from ppma03dal.us.ibm.com (b.bd.3ea9.ip4.static.sl-reverse.com [169.62.189.11]) by mx0a-001b2d01.pphosted.com with ESMTP id 2wy1x19xf7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 17 Dec 2019 16:12:33 -0500 Received: from pps.filterd (ppma03dal.us.ibm.com [127.0.0.1]) by ppma03dal.us.ibm.com (8.16.0.27/8.16.0.27) with SMTP id xBHLAfvn022896; Tue, 17 Dec 2019 21:12:32 GMT Received: from b01cxnp23033.gho.pok.ibm.com (b01cxnp23033.gho.pok.ibm.com [9.57.198.28]) by ppma03dal.us.ibm.com with ESMTP id 2wvqc6qmee-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 17 Dec 2019 21:12:32 +0000 Received: from b01ledav006.gho.pok.ibm.com (b01ledav006.gho.pok.ibm.com [9.57.199.111]) by b01cxnp23033.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id xBHLCVcG40960304 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 17 Dec 2019 21:12:31 GMT Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A3902AC05F; Tue, 17 Dec 2019 21:12:31 +0000 (GMT) Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 157B7AC059; Tue, 17 Dec 2019 21:12:31 +0000 (GMT) Received: from leobras.br.ibm.com (unknown [9.18.235.137]) by b01ledav006.gho.pok.ibm.com (Postfix) with ESMTP; Tue, 17 Dec 2019 21:12:30 +0000 (GMT) Message-ID: Subject: Re: [PATCH] vmsplice.2: SPLICE_F_GIFT became no-op From: Leonardo Bras To: "Michael Kerrisk (man-pages)" , Jens Axboe Cc: linux-man@vger.kernel.org Date: Tue, 17 Dec 2019 18:12:27 -0300 In-Reply-To: References: <20190801222417.14413-1-leonardo@linux.ibm.com> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-IpsV6nMUBpIuLF8D7BMD" User-Agent: Evolution 3.34.1 (3.34.1-1.fc31) MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.95,18.0.572 definitions=2019-12-17_04:2019-12-17,2019-12-17 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=999 bulkscore=0 adultscore=0 mlxscore=0 malwarescore=0 priorityscore=1501 clxscore=1015 suspectscore=0 phishscore=0 spamscore=0 lowpriorityscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1910280000 definitions=main-1912170169 Sender: linux-man-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-man@vger.kernel.org --=-IpsV6nMUBpIuLF8D7BMD Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Fri, 2019-09-13 at 14:55 +0200, Michael Kerrisk (man-pages) wrote: > Hello Jens, >=20 > Would you be willing to take a look at this man-pages bug report > relating to vmsplice()? Hello Jens, Could you please provide feedback on this patch? Thank you, Leonardo Bras >=20 > Thanks, >=20 > Michael >=20 > On 8/2/19 12:24 AM, Leonardo Bras wrote: > > As explained in splice.2, SPLICE_F_MOVE became a no-op, and since it > > is needed to use page gifting, it made SPLICE_F_GIFT a no-op too. > >=20 > > I took a look in current code, and found no use of this flag: > > When enabled, it sets PIPE_BUF_FLAG_GIFT,which is only checked in > > user_page_pipe_buf_steal, which is only used on > > user_page_pipe_buf_ops, as a .steal component. > >=20 > > But, in the whole kernel code, there is no calling of a steal() > > function, making me believe this flag is not used anymore. > >=20 > > Signed-off-by: Leonardo Bras > > --- > > man2/vmsplice.2 | 5 +++++ > > 1 file changed, 5 insertions(+) > >=20 > > diff --git a/man2/vmsplice.2 b/man2/vmsplice.2 > > index 17834607b..94fb86142 100644 > > --- a/man2/vmsplice.2 > > +++ b/man2/vmsplice.2 > > @@ -123,6 +123,11 @@ if this flag is not specified, then a subsequent > > .B SPLICE_F_MOVE > > must copy the pages. > > Data must also be properly page aligned, both in memory and length. > > +Starting in Linux 2.6.21, it is a no-op, because the > > +.B SPLICE_F_MOVE > > +also became a no-op on > > +.BR splice (2) > > +. > > .\" FIXME > > .\" It looks like the page-alignment requirement went away with > > .\" commit bd1a68b59c8e3bce45fb76632c64e1e063c3962d > >=20 >=20 >=20 --=-IpsV6nMUBpIuLF8D7BMD Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEMdeUgIzgjf6YmUyOlQYWtz9SttQFAl35RLsACgkQlQYWtz9S ttTeuxAAuZJ8J6MA9PfBt/Xkl45Lqmnl0rlDJM5kPbpdAaKwRD6fsslcOcczM82D jUSnTVgcQdMKHa9RKT3kcBlCqHNlS+moh92Tm4sxmgMesXYGDOLDK6uEcxk+gBxr o7YDj5FNl+mlGcVQ1pRGpQxp8sGGx1TkWu0utC+dvdiFFPDoEgpVmnUrB56iVqmy y7ndGEowAW4jZl56/FXxDjgUz+oZD4HZLyAwv0qjXtBVz45j1edlZSVcpJJP0tvq vhYHmFWLPfOzWT3i1mcsW07Ww3DTxGnoUY+nyRrMhZ6TRh8Veml2MaxL4aAij7Bu jQMk4uyEswa1R1dVyf8PmAh9yKefh2DxQoAkPxWiSq9B9rqOqkRuQFSPlv7SJwHI ul+JqhZgqO+JWDJo4Aw39n5udM0B+xeyjVH4G3UTEzzHo78vRD/Ucr8U9Idox+vv V5+kH/YF8pdyl30HK9Xqub5TCxodqFKD7gwDEJP57Qtekqgqvl2BsFuWpuUgP1JG 9yPcKiJvrF5XLjvkRPyUQkw0Z8TQAmjH3Dv4v4PGl9x101lgu7ab2AFkTr2jJ9sC b9KDgNzzZ262BzrboiCpXh2yCcy9nYuHKoDtDn3XMKOOyBQ4zzfey5xv98sQYQOs fOZZ3m/6Zaa2LROPFfUsycaLlX/inwyZyX1tIiKheBUEYLDB3QQ= =qUy1 -----END PGP SIGNATURE----- --=-IpsV6nMUBpIuLF8D7BMD--