From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 105327 invoked by alias); 2 Mar 2019 16:48:53 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 105306 invoked by uid 89); 2 Mar 2019 16:48:52 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=2.1 required=5.0 tests=BAYES_00,BODY_8BITS,GARBLED_BODY,SPF_HELO_PASS autolearn=no version=3.3.2 spammy=H*i:sk:9f23983, H*f:sk:9f23983, quality, enter X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Sat, 02 Mar 2019 16:48:51 +0000 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 31646318A5F6; Sat, 2 Mar 2019 16:48:50 +0000 (UTC) Received: from tucnak.zalov.cz (ovpn-117-64.ams2.redhat.com [10.36.117.64]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CDF3060C6C; Sat, 2 Mar 2019 16:48:48 +0000 (UTC) Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.15.2/8.15.2) with ESMTP id x22GmksS012523; Sat, 2 Mar 2019 17:48:46 +0100 Received: (from jakub@localhost) by tucnak.zalov.cz (8.15.2/8.15.2/Submit) id x22Gmhs7012522; Sat, 2 Mar 2019 17:48:43 +0100 Date: Sat, 02 Mar 2019 16:48:00 -0000 From: Jakub Jelinek To: =?utf-8?B?6rmA6rec656Y?= Cc: gcc Mailing List Subject: Re: Implementing an algorithm in place of gomp 'auto' Message-ID: <20190302164843.GD7611@tucnak> Reply-To: Jakub Jelinek References: <935870ac668da7a5fbbfc73ab12f54ba@cweb008.nm.nfra.io> <20190301173229.GV7611@tucnak> <20190301174614.GW7611@tucnak> <9f23983bebac9b9adf5c5b678a85a6f5@cweb003.nm.nfra.io> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <9f23983bebac9b9adf5c5b678a85a6f5@cweb003.nm.nfra.io> User-Agent: Mutt/1.10.1 (2018-07-13) X-IsSubscribed: yes X-SW-Source: 2019-03/txt/msg00011.txt.bz2 On Sat, Mar 02, 2019 at 10:05:25PM +0900, 김규래 wrote: > > It is on the wish list, but I'm afraid I won't have cycles for it in the > > next year or two at least (once GCC 9 is released, I need to work on the > > remaining OpenMP 5.0 features). Of course if somebody implements it and submits > > and it is of reasonable quality/performance, it will be accepted. > > Implementing work stealing (WS) also sounds interesting to me. If you mean work stealing for worksharing loop scheduling, then it would need to be yet another non-standard schedule, the current schedules (except for auto or no schedule clause) don't allow it. If you mean work stealing for task scheduling, then that is more important. > Do you have any plan of how it should look like? > For static scheduling, I don't quite see how WS could be implemented since the control doesn't enter the OMP runtime. Sure, explicit schedule(static, N) or schedule(static) is quite well defined and shouldn't go into the OMP runtime. I was talking about no schedule clause at all, then the spec says it is implementation defined what scheduling is used. > Lastly, do you think the subjects we are discussing (Additional scheduling algorithms, doing something about auto, WS etc..) > could make the cut for a GSoC 2019 project? I think so. If you'd be interested in task scheduling, even better, but if not, I think enough work can be done on worksharing loop scheduling. Jakub