From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from esa4.mentor.iphmx.com (esa4.mentor.iphmx.com [68.232.137.252]) by sourceware.org (Postfix) with ESMTPS id 4021B3858D39 for ; Wed, 8 Feb 2023 07:47:57 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 4021B3858D39 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=codesourcery.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=mentor.com X-IronPort-AV: E=Sophos;i="5.97,280,1669104000"; d="scan'208";a="96187938" Received: from orw-gwy-02-in.mentorg.com ([192.94.38.167]) by esa4.mentor.iphmx.com with ESMTP; 07 Feb 2023 23:47:55 -0800 IronPort-SDR: 60q3XEOcX8OvzKLE4TLZZzaSL3+VziWzPiYvwfWSObP4rfNYQm9D3GbqLyJcpEYVq+loYGKcDr XW000fHUZdX0Yst2CqqxG2nE2R3mzsBIhKXf1Rji3OBOKC2olSH6D+3Gp/IGkij54M/HXhpcI6 U6w6sQNhNJX5otXHFi0j7dieWl8sBqK8nUjylTidYG7ZYgXSfaLtiu7ofw4Yup+P+QT4Ysfe8H FX8ReRUsDP74d6/q/JQBY8N+YQVikFVVTX/ZXV2i3dCLwGhihVmOyeHKtjNRqoacTsRH1k+JyP NNs= Message-ID: <22bdce2a-4cf5-d2da-b85b-ed16cce49d70@codesourcery.com> Date: Wed, 8 Feb 2023 08:47:46 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.7.1 Subject: Re: GSoC project idea: Separate Host Process Offloading Content-Language: en-US To: Thomas Schwinge , Martin Jambor , Richard Biener , Jakub Jelinek CC: Hongtao Liu , Michael Matz , References: <87v8kjojnz.fsf@euler.schwinge.homeip.net> <87ilgdcb0n.fsf@euler.schwinge.homeip.net> From: Tobias Burnus In-Reply-To: <87ilgdcb0n.fsf@euler.schwinge.homeip.net> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: quoted-printable X-Originating-IP: [137.202.0.90] X-ClientProxiedBy: svr-ies-mbx-11.mgc.mentorg.com (139.181.222.11) To svr-ies-mbx-12.mgc.mentorg.com (139.181.222.12) X-Spam-Status: No, score=-5.9 required=5.0 tests=BAYES_00,HEADER_FROM_DIFFERENT_DOMAINS,KAM_DMARC_STATUS,KAM_SHORT,NICE_REPLY_A,SPF_HELO_PASS,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: Hi Thomas, hi all, On 08.02.23 00:26, Thomas Schwinge wrote: > On 2023-02-02T22:13:20+0100, I wrote: >> I'd offer to co-mentor, but I'd rather not be the only one. > Still looking for someone to join, please! :-) As kind of mentioned before, I am willing to co-mentor :-) > Here it is: > https://gcc.gnu.org/wiki/SummerOfCode#Separate_Host_Process_Offloading > Please have a look, and fix up if necessary. Thanks. (Disclaimer: I still have to read it.) I think this could be also the basis for remote OpenMP offload handling via the to-be-created target-specific plugin. In this case, to do offloading to the remote CPU. Writing such an RPC wrapper would be an independent task, which then should also handle the offloading to a remote GPU. =E2=80=94 Citing an LLVM paper about such a feature: "The basic idea behind the Remote OpenMP Offloading implementation is to provide a transparent communication channel between the target-independent library on the host with the target-dependent library on the remote system. This use case matches the well-known remote procedure calls (RPC) idiom. To facilitate communication, we added two new components into LLVM/OpenMP that build a tunnel from the host to the remote system through which all plugin API calls ( in Fig. 3) are forwarded. The first is a remote offloading plugin () which presents itself to the host as any other plugin would, i.e., it looks no different than the NVIDIA GPU offloading plugin. The second is a server application that must be running on the remote system () that mimics when it communicates with the remote device plugin, such as the one for NVIDIA GPU offloading. The bottom row of Fig. 3 illustrates their interaction with the existing infrastructure." (From https://link.springer.com/chapter/10.1007/978-3-031-07312-0_16 (requires subscription)) About this topic, see also https://www.hpcwire.com/off-the-wire/remote-openmp-offloading-paper-recogni= zed-at-isc/ and https://baodishan.com/assets/pdf/iwomp22.pdf (both freely accessible, the latter has a lot of details). Tobias ----------------- Siemens Electronic Design Automation GmbH; Anschrift: Arnulfstra=C3=9Fe 201= , 80634 M=C3=BCnchen; Gesellschaft mit beschr=C3=A4nkter Haftung; Gesch=C3= =A4ftsf=C3=BChrer: Thomas Heurung, Frank Th=C3=BCrauf; Sitz der Gesellschaf= t: M=C3=BCnchen; Registergericht M=C3=BCnchen, HRB 106955