From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 46708 invoked by alias); 26 Feb 2018 16:38:33 -0000 Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org Received: (qmail 46692 invoked by uid 89); 26 Feb 2018 16:38:33 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.6 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_LOW,SPF_PASS,T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 spammy=HTo:U*devel, CMA, cma, heard X-HELO: mr26p42im-ztdg06103201.me.com Received: from mr26p42im-ztdg06103201.me.com (HELO mr26p42im-ztdg06103201.me.com) (17.111.243.30) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Mon, 26 Feb 2018 16:38:31 +0000 Received: from process-dkim-sign-daemon.mr26p42im-ztdg06103201.me.com by mr26p42im-ztdg06103201.me.com (Oracle Communications Messaging Server 8.0.1.2.20170607 64bit (built Jun 7 2017)) id <0P4R00M00NJOOO00@mr26p42im-ztdg06103201.me.com> for gdb@sourceware.org; Mon, 26 Feb 2018 16:38:24 +0000 (GMT) Received: from icloud.com ([127.0.0.1]) by mr26p42im-ztdg06103201.me.com (Oracle Communications Messaging Server 8.0.1.2.20170607 64bit (built Jun 7 2017)) with ESMTPSA id <0P4R001KJNJW5330@mr26p42im-ztdg06103201.me.com>; Mon, 26 Feb 2018 16:38:23 +0000 (GMT) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2018-02-26_06:,, signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 clxscore=1011 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1802260218 From: Nathan Hjelm Message-id: Content-type: multipart/signed; boundary="Apple-Mail=_6A54AC93-1F7E-43B9-A4A6-B8E2291C2347"; protocol="application/pgp-signature"; micalg=pgp-sha512 MIME-version: 1.0 (Mac OS X Mail 11.2 \(3445.5.20\)) Subject: Re: [OMPI devel] [PATCH v5 0/4] vm: add a syscall to map a process memory into a pipe Date: Mon, 26 Feb 2018 16:38:00 -0000 In-reply-to: <3122ec5a-7f73-f6b4-33ea-8c10ef32e5b0@virtuozzo.com> Cc: Andrew Morton , Mike Rapoport , Andrei Vagin , Arnd Bergmann , Jann Horn , rr-dev@mozilla.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, Josh Triplett , criu@openvz.org, linux-mm@kvack.org, Greg KH , Alexander Viro , gdb@sourceware.org, linux-fsdevel@vger.kernel.org, Thomas Gleixner , Michael Kerrisk To: Open MPI Developers References: <1515479453-14672-1-git-send-email-rppt@linux.vnet.ibm.com> <20180220164406.3ec34509376f16841dc66e34@linux-foundation.org> <3122ec5a-7f73-f6b4-33ea-8c10ef32e5b0@virtuozzo.com> X-SW-Source: 2018-02/txt/msg00103.txt.bz2 --Apple-Mail=_6A54AC93-1F7E-43B9-A4A6-B8E2291C2347 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii Content-length: 1363 All MPI implementations have support for using CMA to transfer data between= local processes. The performance is fairly good (not as good as XPMEM) but= the interface limits what we can do with to remote process memory (no atom= ics). I have not heard about this new proposal. What is the benefit of the = proposed calls over the existing calls? -Nathan > On Feb 26, 2018, at 2:02 AM, Pavel Emelyanov wrote: >=20 > On 02/21/2018 03:44 AM, Andrew Morton wrote: >> On Tue, 9 Jan 2018 08:30:49 +0200 Mike Rapoport wrote: >>=20 >>> This patches introduces new process_vmsplice system call that combines >>> functionality of process_vm_read and vmsplice. >>=20 >> All seems fairly strightforward. The big question is: do we know that >> people will actually use this, and get sufficient value from it to >> justify its addition? >=20 > Yes, that's what bothers us a lot too :) I've tried to start with finding= out if anyone > used the sys_read/write_process_vm() calls, but failed :( Does anybody kn= ow how popular > these syscalls are? If its users operate on big amount of memory, they co= uld benefit from > the proposed splice extension. >=20 > -- Pavel > _______________________________________________ > devel mailing list > devel@lists.open-mpi.org > https://lists.open-mpi.org/mailman/listinfo/devel --Apple-Mail=_6A54AC93-1F7E-43B9-A4A6-B8E2291C2347 Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=signature.asc Content-Type: application/pgp-signature; name=signature.asc Content-Description: Message signed with OpenPGP Content-length: 833 -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEE2GIIdNgp/fA6+otZb+5NXWbsZioFAlqUN/sACgkQb+5NXWbs Ziqqvg//VVpRs73U8FH12mV10hzJmQEVssOgHVrroVBeg0oRjVFsUp8fJxxvV9iC DZ+yylG7T5K7V1ixlbv1Uw9nj79CB99HQuTtXARv7Rab2opcWWh2MktEV9+8iM7f xCXc+JCQfd6ncL/codqUTry+F++1K3fIanRj2/TtK0fr45uNODAPxS8FIxMl5NYg hym0BEmZkwKm5BKZbWqlDq3ES2HSrIHHXw33liTJcWQSnmsV1KLWMPvJwVWKF/s2 eyrLBASiwbNw+BkZXY3LSqRRXU8pJM1HQo4PKsiMp+caBGypeSgq4WDn6i9vmfFW qUZmtNYzlnpFLNiFJBIfPYIoYrsondHCDD7U7V2tS+j70hG5/5apj3Mgu4mBBm5L DQpfyiCPLE6objfpt1qd+fqWTLNpbQAS1elctmxqDL1MgXQXrjMgOrbZJPLUzP5q 6EfTw09wOUjtpl6dmB5g4UvnJztTRTHGTkS/DNl6UhSnGGK7EC442hAhkMjs8/Yh zbc6/LxXu8B7k5VBopKx8nxISbq00A1Y1loPlsOaKx581RsUaIrpl1bUx3t62QzC 8MbuNZWqj4ogv2VIxJBP3h/YI8Hedzjckzy/aHVkwyj5N+iHjHmXGGPFm/7q9lm/ os5LIAQQ/F5pE1wqZq3EE3XLSXMP8fU2q+YjaVYXr7a+IX4MVbM= =HLfy -----END PGP SIGNATURE----- --Apple-Mail=_6A54AC93-1F7E-43B9-A4A6-B8E2291C2347--