From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from esa2.mentor.iphmx.com (esa2.mentor.iphmx.com [68.232.141.98]) by sourceware.org (Postfix) with ESMTPS id 8EA9A3858D33 for ; Tue, 7 Feb 2023 23:26:57 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 8EA9A3858D33 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="5.97,279,1669104000"; d="scan'208";a="97310701" Received: from orw-gwy-01-in.mentorg.com ([192.94.38.165]) by esa2.mentor.iphmx.com with ESMTP; 07 Feb 2023 15:26:56 -0800 IronPort-SDR: TNEI0FvkCIbmTMwdvI6Cya1IgrC6mQnpROG0aE3KdkrDFl7ur2f6e43uTVw1Y3XpJ2697M6h6r kNXUfIfotvz9p2J7MDRGjX/4Isbeo+Fs59SEAHfY0koJwkgL+jl9j64FEw4NhMJ2fIOHb9pQPA gYUfcQ+sjbCuv5ufS8WGMAhlx6vNsTbQHRQaYscEtUUPHeBPWhLu94StfDHswwssEIGptKUoDs iY4lHLcVyCh03hqsuoc7/YmbGjtj6jysEPJ3j+FedB7lrUo25hSdJJLiy/I+bx+vDv+zpF2pyH 2C4= From: Thomas Schwinge To: Martin Jambor , Richard Biener , Jakub Jelinek CC: Tobias Burnus , Hongtao Liu , Michael Matz , Subject: Re: GSoC project idea: Separate Host Process Offloading In-Reply-To: <87v8kjojnz.fsf@euler.schwinge.homeip.net> References: <87v8kjojnz.fsf@euler.schwinge.homeip.net> User-Agent: Notmuch/0.29.3+94~g74c3f1b (https://notmuchmail.org) Emacs/28.2 (x86_64-pc-linux-gnu) Date: Wed, 8 Feb 2023 00:26:48 +0100 Message-ID: <87ilgdcb0n.fsf@euler.schwinge.homeip.net> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Originating-IP: [137.202.0.90] X-ClientProxiedBy: svr-ies-mbx-12.mgc.mentorg.com (139.181.222.12) To svr-ies-mbx-10.mgc.mentorg.com (139.181.222.10) X-Spam-Status: No, score=-5.9 required=5.0 tests=BAYES_00,HEADER_FROM_DIFFERENT_DOMAINS,KAM_DMARC_STATUS,KAM_SHORT,RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS,TXREP autolearn=no 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! On 2023-02-02T22:13:20+0100, I wrote: > On 2023-02-01T16:12:07+0100, Martin Jambor wrote: >> On Thu, Oct 20 2022, Richard Biener via Gcc-patches wrote: >>>> Am 20.10.2022 um 14:41 schrieb Jakub Jelinek via Gcc-patches : >>>> =EF=BB=BFOn Thu, Oct 20, 2022 at 12:33:28PM +0000, Michael Matz wrote: >>>>>> On Thu, 20 Oct 2022, Thomas Schwinge wrote: >>>>>> This had been done in >>>>>> wwwdocs commit 5c7ecfb5627e412a3d142d8dc212f4cd39b3b73f >>>>>> "Document deprecation of OpenMP MIC offloading in GCC 12". >>>>>> >>>>>> I'm sad about this, because -- in theory -- such a plugin is very us= eful >>>>>> for offloading simulation/debugging (separate host/device memory spa= ces, >>>>>> allow sanitizers to run on offloaded code >>>>> >>>>> Yeah, I think that's a _very_ useful feature, but indeed ... >>>>> >>>>>> (like LLVM a while ago >>>>>> implemented), and so on), but all that doesn't help -- in practice -= - if >>>>>> nobody is maintaining that code. >>>>> >>>>> ... it should then be somewhat maintained properly. Maybe the >>>>> MIC-specifics could be removed from the code, and it could be transfo= rmed >>>>> into a "null"-offload target, as example and testing vehicle (and imp= lying >>>>> that such new liboffloadmic^H^H^Hnull would have its upstream in the = GCC >>>>> repo). Alas, if noone is going to do that work removing is the right >>>>> choice. >>>> >>>> Yeah. But we really shouldn't need a large MIC specific library for t= hat, >>>> everything should be implementable with a simple portable plugin that = just >>>> forks + execs the offloading ELF and transfers data to/out of it etc. >>>> And the config/i386/intelmic-mkoffload etc. stuff would need to be don= e >>>> somewhere in generic code, such that we can do it for all targets. >>>> Also ideally by using just the normal lto1 with some special option th= at >>>> it acts as an offloading compiler, so that we don't need to bother wit= h >>>> building a separate offloading compiler for it. >>>> True, everything guarded with #ifdef ACCEL_COMPILER etc. would need to >>>> change into code guarded with some option. >>> >>> Might be a nice GSoC project =E2=80=A6 >> >> I really think it could be. > > Agreed! Something like: "Separate Host Process Offloading"! (Back > in October, I actually had made a TODO note to put this one onto > , but so far...) > >> Would any one of those involved in this >> thread be willing to mentor it? > > I'd offer to co-mentor, but I'd rather not be the only one. Still looking for someone to join, please! :-) > I'm now off for FOSDEM, but unless someone gets it done before, I'll cook > up a GSoC project idea text when I'm back, on Tuesday. Here it is: . Please have a look, and fix up if necessary. Gr=C3=BC=C3=9Fe Thomas ----------------- 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