From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 08F71C433ED for ; Thu, 29 Apr 2021 12:14:25 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7F73A61458 for ; Thu, 29 Apr 2021 12:14:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7F73A61458 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ffwll.ch Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B97896EE7E; Thu, 29 Apr 2021 12:14:23 +0000 (UTC) Received: from mail-wm1-x32c.google.com (mail-wm1-x32c.google.com [IPv6:2a00:1450:4864:20::32c]) by gabe.freedesktop.org (Postfix) with ESMTPS id D62046EE7E for ; Thu, 29 Apr 2021 12:14:22 +0000 (UTC) Received: by mail-wm1-x32c.google.com with SMTP id s82so660712wmf.3 for ; Thu, 29 Apr 2021 05:14:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=8DC9ozkq9NhLoH8QWyc5Az9r2IL7rkBQY4hDTI1sLuM=; b=cJIPNJaPbSNadhuBRzX0WUZaIPB+1rlsCcZZTRBbmb01UWhMl9at1e8bHSOCsgJUw+ 9iMMEB1Whd7BUtgfhrr2uXo9EBVABOIJkvPCJ2aBMhneu0xwnReFkO68TRww8lRkcme1 2iF8PPMVaTqh2IDwSw/29sC5xJ+C89hxT/xWI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=8DC9ozkq9NhLoH8QWyc5Az9r2IL7rkBQY4hDTI1sLuM=; b=kty24jpx2OEaO6BsXSsFNM7s+VUekIcqc+PZwwaQWNC2gWsWXcdqp7bILeR4E6xImW B+KuFc8QIsDM4ARdCrs55fM6A4Gmths4m+f3cr7C0/QirCIEgV5gmjYIkMsSi34/5Lye iFQfFSZ6rRzs88dp3Q/0KxW2glAcdBzo9dC1wnCZhrVO0MVzkRGPuuACtATU+a9ghrG3 38LmyGJ23g4DRvV13ZG53/uCCnuHPDM41wj/4YKjGRAPHKWrL8yLkY46fioZzQsV9zjL 1Jy8bRsUXfeGtEpts5YBcoIpKQqt9d3/7Ot/UvA8e7YsQ371FsCecJp85gJelUpNjg9t TOkw== X-Gm-Message-State: AOAM533/gnjWC+h41XcBYWrKr/nttyKmeMGKT+MHfH9cF84lApw14Qyl p7xPu0/8++fW4geE5hY+xvUexw== X-Google-Smtp-Source: ABdhPJwlY5WYu7LKwW0ZED5+a9NSGe3OUZ8+gMWIY+vqxv/0AepSLn+8MgJ6evcPDrfLjkuzsDx8MQ== X-Received: by 2002:a1c:2985:: with SMTP id p127mr37033775wmp.165.1619698461519; Thu, 29 Apr 2021 05:14:21 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id d13sm4620141wrx.29.2021.04.29.05.14.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 29 Apr 2021 05:14:20 -0700 (PDT) Date: Thu, 29 Apr 2021 14:14:19 +0200 From: Daniel Vetter To: Jason Ekstrand Subject: Re: [Intel-gfx] [PATCH 08/21] drm/i915/gem: Disallow bonding of virtual engines Message-ID: References: <20210423223131.879208-1-jason@jlekstrand.net> <20210423223131.879208-9-jason@jlekstrand.net> <20210428171853.GA3260@sdutt-i7> <20210428175525.GA7224@sdutt-i7> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Operating-System: Linux phenom 5.10.32scarlett+ X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Matthew Brost , Intel GFX , Maling list - DRI developers Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Wed, Apr 28, 2021 at 01:17:27PM -0500, Jason Ekstrand wrote: > On Wed, Apr 28, 2021 at 1:02 PM Matthew Brost wrote: > > > > On Wed, Apr 28, 2021 at 12:46:07PM -0500, Jason Ekstrand wrote: > > > On Wed, Apr 28, 2021 at 12:26 PM Matthew Brost wrote: > > > > Jumping on here mid-thread. For what is is worth to make execlists work > > > > with the upcoming parallel submission extension I leveraged some of the > > > > existing bonding code so I wouldn't be too eager to delete this code > > > > until that lands. > > > > > > Mind being a bit more specific about that? The motivation for this > > > patch is that the current bonding handling and uAPI is, well, very odd > > > and confusing IMO. It doesn't let you create sets of bonded engines. > > > Instead you create engines and then bond them together after the fact. > > > I didn't want to blindly duplicate those oddities with the proto-ctx > > > stuff unless they were useful. With parallel submit, I would expect > > > we want a more explicit API where you specify a set of engine > > > class/instance pairs to bond together into a single engine similar to > > > how the current balancing API works. > > > > > > Of course, that's all focused on the API and not the internals. But, > > > again, I'm not sure how we want things to look internally. What we've > > > got now doesn't seem great for the GuC submission model but I'm very > > > much not the expert there. I don't want to be working at cross > > > purposes to you and I'm happy to leave bits if you think they're > > > useful. But I thought I was clearing things away so that you can put > > > in what you actually want for GuC/parallel submit. > > > > > > > Removing all the UAPI things are fine but I wouldn't delete some of the > > internal stuff (e.g. intel_virtual_engine_attach_bond, bond > > intel_context_ops, the hook for a submit fence, etc...) as that will > > still likely be used for the new parallel submission interface with > > execlists. As you say the new UAPI wont allow crazy configurations, > > only simple ones. > > I'm fine with leaving some of the internal bits for a little while if > it makes pulling the GuC scheduler in easier. I'm just a bit > skeptical of why you'd care about SUBMIT_FENCE. :-) Daniel, any > thoughts? Yeah I'm also wondering why we need this. Essentially your insight (and Tony Ye from media team confirmed) is that media umd never uses bonded on virtual engines. So the only thing we need is the await_fence submit_fence logic to stall the subsequent patches just long enough. I think that stays. All the additional logic with the cmpxchg lockless trickery and all that isn't needed, because we _never_ have to select an engine for bonded submission: It's always the single one available. This would mean that for execlist parallel submit we can apply a limitation (beyond what GuC supports perhaps) and it's all ok. With that everything except the submit fence await logic itself can go I think. Also one for Matt: We decided to ZBB implementing parallel submit on execlist, it's going to be just for GuC. At least until someone starts screaming really loudly. Cheers, Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel