From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f69.google.com (mail-pg0-f69.google.com [74.125.83.69]) by kanga.kvack.org (Postfix) with ESMTP id B9EEE6B0008 for ; Mon, 26 Feb 2018 11:38:28 -0500 (EST) Received: by mail-pg0-f69.google.com with SMTP id l14so5743199pgn.21 for ; Mon, 26 Feb 2018 08:38:28 -0800 (PST) Received: from mr26p42im-ztdg06103201.me.com (mr26p42im-ztdg06103201.me.com. [17.111.243.30]) by mx.google.com with ESMTPS id s19si6964473pfk.260.2018.02.26.08.38.27 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 26 Feb 2018 08:38:27 -0800 (PST) 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 linux-mm@kvack.org; Mon, 26 Feb 2018 16:38:24 +0000 (GMT) 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 09:38:19 -0700 In-reply-to: <3122ec5a-7f73-f6b4-33ea-8c10ef32e5b0@virtuozzo.com> References: <1515479453-14672-1-git-send-email-rppt@linux.vnet.ibm.com> <20180220164406.3ec34509376f16841dc66e34@linux-foundation.org> <3122ec5a-7f73-f6b4-33ea-8c10ef32e5b0@virtuozzo.com> Sender: owner-linux-mm@kvack.org List-ID: To: Open MPI Developers 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 --Apple-Mail=_6A54AC93-1F7E-43B9-A4A6-B8E2291C2347 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii 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 atomics). 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 = know how popular > these syscalls are? If its users operate on big amount of memory, they = could 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 -----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-- -- 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