From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=uz8r=HN=lists.freedesktop.org=nouveau-bounces@kernel.org>
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=-5.3 required=3.0 tests=BAYES_00,DKIM_INVALID,
	DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,
	SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 2E832C433E0
	for <nouveau@archiver.kernel.org>; Thu, 11 Feb 2021 02:26:20 +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 C93E264E30
	for <nouveau@archiver.kernel.org>; Thu, 11 Feb 2021 02:26:19 +0000 (UTC)
DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C93E264E30
Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nvidia.com
Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=nouveau-bounces@lists.freedesktop.org
Received: from gabe.freedesktop.org (localhost [127.0.0.1])
	by gabe.freedesktop.org (Postfix) with ESMTP id D517E6E171;
	Thu, 11 Feb 2021 02:26:18 +0000 (UTC)
Received: from hqnvemgate26.nvidia.com (hqnvemgate26.nvidia.com
 [216.228.121.65])
 by gabe.freedesktop.org (Postfix) with ESMTPS id ED06A6E171;
 Thu, 11 Feb 2021 02:26:17 +0000 (UTC)
Received: from hqmail.nvidia.com (Not Verified[216.228.121.13]) by
 hqnvemgate26.nvidia.com (using TLS: TLSv1.2, AES256-SHA)
 id <B602495c80000>; Wed, 10 Feb 2021 18:26:16 -0800
Received: from [10.2.50.67] (172.20.145.6) by HQMAIL107.nvidia.com
 (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 11 Feb
 2021 02:26:16 +0000
To: Alistair Popple <apopple@nvidia.com>, Linux MM <linux-mm@kvack.org>,
 Nouveau Dev <nouveau@lists.freedesktop.org>, Ben Skeggs <bskeggs@redhat.com>, 
 Andrew Morton <akpm@linux-foundation.org>, Linux Doc Mailing List
 <linux-doc@vger.kernel.org>, Linux Kernel Mailing List
 <linux-kernel@vger.kernel.org>, <kvm-ppc@vger.kernel.org>, dri-devel
 <dri-devel@lists.freedesktop.org>, Ralph Campbell <rcampbell@nvidia.com>,
 Jerome Glisse <jglisse@redhat.com>, Jason Gunthorpe <jgg@ziepe.ca>
References: <20210209010722.13839-1-apopple@nvidia.com>
 <CAKMK7uGwg2-DTU7Zrco=TSkcR4yTqN1AF0hvVYEAbuj4BUYi5Q@mail.gmail.com>
 <3426910.QXTomnrpqD@nvdebian>
 <CAKMK7uHp+BzHF1=JhKjv5HYm_j0SVqsGdRqjUxVFYx4GSEPucg@mail.gmail.com>
 <57fe0deb-8bf6-d3ee-3545-11109e946528@nvidia.com>
 <YCPYtNeYCuu6i2/d@phenom.ffwll.local>
From: John Hubbard <jhubbard@nvidia.com>
Message-ID: <2906f445-babb-5f4e-2d99-dc004ae1face@nvidia.com>
Date: Wed, 10 Feb 2021 18:26:15 -0800
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:85.0) Gecko/20100101
 Thunderbird/85.0
MIME-Version: 1.0
In-Reply-To: <YCPYtNeYCuu6i2/d@phenom.ffwll.local>
Content-Language: en-US
X-Originating-IP: [172.20.145.6]
X-ClientProxiedBy: HQMAIL111.nvidia.com (172.20.187.18) To
 HQMAIL107.nvidia.com (172.20.187.13)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1;
 t=1613010376; bh=fWiSyOBWsVzyVm55YFwZ6S/xqnjzAJ77D4BJX4IdmYQ=;
 h=Subject:To:References:From:Message-ID:Date:User-Agent:
 MIME-Version:In-Reply-To:Content-Type:Content-Language:
 Content-Transfer-Encoding:X-Originating-IP:X-ClientProxiedBy;
 b=leaB4fiXqE16gCtniTXQN7wSpNK6vqgNBnsubO6Sqz20znNTYyS1DivzYTMRS4UV7
 w5Vir0tdNZkJIZJNa7GWAZkmqVslmOQbbFoYCui9m3qncJPbiLoeAgW6aOlHumrkeb
 AvqNZnglqc7Brug+AtJ88e4mmqyLBYYytyn9i/agt07SeilKDzj3ypZZzMaPyEc/1f
 qfcVy3BbtVAyuYqrqLZA+t6jewjnFT5OuJgR0tr56q4bF5w7n5XURdxoT6MgKpdprH
 LtGPzO04XwunHPGKsOBJRZoELR3w5OcRZukw35gXqIHSILXS8DAoXlexMKrAUC4a98
 gWaYeMFi1C9IA==
Subject: Re: [Nouveau] [PATCH 0/9] Add support for SVM atomics in Nouveau
X-BeenThere: nouveau@lists.freedesktop.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Nouveau development list <nouveau.lists.freedesktop.org>
List-Unsubscribe: <https://lists.freedesktop.org/mailman/options/nouveau>,
 <mailto:nouveau-request@lists.freedesktop.org?subject=unsubscribe>
List-Archive: <https://lists.freedesktop.org/archives/nouveau>
List-Post: <mailto:nouveau@lists.freedesktop.org>
List-Help: <mailto:nouveau-request@lists.freedesktop.org?subject=help>
List-Subscribe: <https://lists.freedesktop.org/mailman/listinfo/nouveau>,
 <mailto:nouveau-request@lists.freedesktop.org?subject=subscribe>
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset="us-ascii"; Format="flowed"
Errors-To: nouveau-bounces@lists.freedesktop.org
Sender: "Nouveau" <nouveau-bounces@lists.freedesktop.org>

On 2/10/21 4:59 AM, Daniel Vetter wrote:
...
>> GPU atomic operations to sysmem are hard to categorize, because because application
>> programmers could easily write programs that do a long series of atomic operations.
>> Such a program would be a little weird, but it's hard to rule out.
> 
> Yeah, but we can forcefully break this whenever we feel like by revoking
> the page, moving it, and then reinstating the gpu pte again and let it
> continue.

Oh yes, that's true.

> 
> If that's no possible then what we need here instead is an mlock() type of
> thing I think.
No need for that, then.


thanks,
-- 
John Hubbard
NVIDIA
_______________________________________________
Nouveau mailing list
Nouveau@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/nouveau