From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from esa1.mentor.iphmx.com (esa1.mentor.iphmx.com [68.232.129.153]) by sourceware.org (Postfix) with ESMTPS id E2DD73839830 for ; Wed, 30 Jun 2021 08:28:16 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org E2DD73839830 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=codesourcery.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=mentor.com IronPort-SDR: h+mGus/4KtcYPwmJZvcPxVLwEtgYm9rI1cyU/092k0i7SSjxQezYf4yjAU6rbhRkLijWCnRR/I AxA7TcvGtcKBfNGfoQA0CR3R+xJ8+3q1/xC5UrcLXTTapW0OErm2Y3ddJT2qOS5VdxQ5LTqXlC ZGDbPRHh7XysBVoNWKydm2P4XjiwzY6FrrXViu1S+L/r/rXTteCCgxnDwreNWvYNzp5D/An7vZ tqwiJyjFazqCqrZlJr6Su/4ZLCT+5LVVk+8ER2m4Jp6yThhge0mCds8CTlmvtNYaV2SNkP/wRc p5c= X-IronPort-AV: E=Sophos;i="5.83,311,1616486400"; d="scan'208";a="65412535" Received: from orw-gwy-02-in.mentorg.com ([192.94.38.167]) by esa1.mentor.iphmx.com with ESMTP; 30 Jun 2021 00:28:15 -0800 IronPort-SDR: mpakureZM1loQr5tdzFQaLgCqtmGmzDz7672uADF+ZdZpZSvP2iAaMn2mn/KE4M3imDy19HAt2 edTGp1Fo0tVX3o55+517vvjDFWDYO948kNwRJYMkSyDLlpb/07E9lhVSeqHkGyF+iQD8SNX6DI 3MILz4gqRiKQz53qszdrBcEjfdBqhCuXrU5nKMVYkQ8kxon6ALpHvotuj0WJY0ziU2ZxgGftlu w2TUaiLyYIBqBBmc/nNedOzW4XjEsDi8Ifu+n5lnTy7ppnC8PksVaOWEq851zZCklai9bKcb49 rxU= From: Thomas Schwinge To: Julian Brown CC: , Jakub Jelinek , "Chung-Lin Tang" Subject: Re: [PATCH 0/4] openacc: Async fixes In-Reply-To: References: User-Agent: Notmuch/0.29.3+94~g74c3f1b (https://notmuchmail.org) Emacs/27.1 (x86_64-pc-linux-gnu) Date: Wed, 30 Jun 2021 10:28:00 +0200 Message-ID: <87pmw3ycxb.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-09.mgc.mentorg.com (139.181.222.9) To svr-ies-mbx-01.mgc.mentorg.com (139.181.222.1) X-Spam-Status: No, score=-6.4 required=5.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, KAM_DMARC_STATUS, SPF_HELO_PASS, SPF_PASS, TXREP autolearn=no autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 30 Jun 2021 08:28:20 -0000 Hi Julian! On 2021-06-29T16:42:00-0700, Julian Brown wrote: > This patch series contains fixes for various problems with async support > for OpenACC at present: Thanks, I shall be looking into these in detail, "soonish". Some quick comments. > - Asynchonous host-to-device copies invoked from within libgomp > (target.c) could copy bad data to the target -- and the workaround > for that currently used in the AMD GCN target plugin could lead to > a different problem (a race condition). As per discussion on Monday, I like to you moved (back?) the "ephemeral" handling into 'libgomp/target.c:gomp_copy_host2dev'. > - The OpenACC profiling-interface implementation did not measure > asynchronous operations properly. We'll need to be careful: (possibly, an older version of) that one we internally had identified to be causing some issues; see the "acc_prof-parallel-1.c intermittent failure on og10 branch" emails, 2020-07. > - Several test cases misuse OpenACC asynchronous support (more race > conditions). Mostly ACK, but some more changes may be necessary; please see (you were CCed). > .../libgomp.oacc-c-c++-common/deep-copy-10.c | 14 +- Please provide some detail about that one ("Fix async behaviour"). It's not obvious to me what's wrong with the current version (but I haven't really spent time on that yet). Gr=C3=BC=C3=9Fe Thomas ----------------- Mentor Graphics (Deutschland) GmbH, Arnulfstrasse 201, 80634 M=C3=BCnchen R= egistergericht M=C3=BCnchen HRB 106955, Gesch=C3=A4ftsf=C3=BChrer: Thomas H= eurung, Frank Th=C3=BCrauf