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 E0339C4361B for ; Mon, 14 Dec 2020 09:52:43 +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 922C5224B1 for ; Mon, 14 Dec 2020 09:52:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 922C5224B1 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 CD4C96E12E; Mon, 14 Dec 2020 09:52:42 +0000 (UTC) Received: from mail-wr1-x432.google.com (mail-wr1-x432.google.com [IPv6:2a00:1450:4864:20::432]) by gabe.freedesktop.org (Postfix) with ESMTPS id A1F2C6E12E for ; Mon, 14 Dec 2020 09:52:41 +0000 (UTC) Received: by mail-wr1-x432.google.com with SMTP id a11so8056350wrr.13 for ; Mon, 14 Dec 2020 01:52:41 -0800 (PST) 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:content-transfer-encoding:in-reply-to; bh=Is54IP16ttSo/VNvqr/hFl8/mWm4JUrt7UNDEyOpIRE=; b=jtoE+j4EvDfGFYAHIOrUQobSiK+iCBZq7nQIqFo4CghFgRW6EvK+bpv8Ei4MbAUCfv BCMxW30nzS41RYzhz705An3EY2Rb1Jsf3yK8AqKqAfHwQS/kHXaaowZQ+uS/37rb/A4P XUv3IxrDK+/9ODqUOGCmOUvx/6ttqyq7wB3jo= 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:content-transfer-encoding :in-reply-to; bh=Is54IP16ttSo/VNvqr/hFl8/mWm4JUrt7UNDEyOpIRE=; b=Ph7QurybcpnHiCYphnMFEOBl7YKbf5bDmg+E5qEpT8EukNdysk+DCx+TqyNkBa86Gs z4pMGLcbooucYRIDZGx/TMYWr1dxVzoNhB58lzAhY4gopQ3Km+XGewZVypgSD0Sl9830 cWcRqhBDPxu49TZnuW8y4RRbnZUCSHEFAoQOfGSJSZBXyE2CLk1a+XEdreAcbXM/7VpW 0mxBje8VlcQ0WFiQHxZaQjXAtESL4XKyOJOchZn8SneKKueLdLvXtzTubLvOBo7Tce74 CHpNwgBszX6B4hqUFDL70uZBPsbVrJe8gSGbKgk0u+EecHAMNE9KHr/xKLPaDZh3ox+D WCMg== X-Gm-Message-State: AOAM532/MIt/DRY3KM2YtVCQKhfMdCfaI5caEffK87HZxBSCwObzyvva toqjrLzU8wdPokomNpi3ajPGWw== X-Google-Smtp-Source: ABdhPJyG3aUDYzxeiyqsL9q8bNxB3GjCWQCdKuR/dxCzX21zyRps6pbnLy5wrRbtvY04MXWeHfjhRA== X-Received: by 2002:a5d:5385:: with SMTP id d5mr24280689wrv.384.1607939560392; Mon, 14 Dec 2020 01:52:40 -0800 (PST) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id h4sm5361555wrt.65.2020.12.14.01.52.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 14 Dec 2020 01:52:39 -0800 (PST) Date: Mon, 14 Dec 2020 10:52:37 +0100 From: Daniel Vetter To: Thomas =?iso-8859-1?Q?Hellstr=F6m_=28Intel=29?= Subject: Re: Fence wait in mmu_interval_notifier_ops::invalidate Message-ID: <20201214095237.GX401619@phenom.ffwll.local> References: <912c29f1-4e17-8b66-419b-1854d03845fd@shipmail.org> <20201209163731.GU552508@nvidia.com> <1b52322f-569e-f523-3baa-ffb822cb72c2@amd.com> <7be4d61e-c82f-6acf-a618-9db29d05094a@shipmail.org> <20201211124618.GC552508@nvidia.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Operating-System: Linux phenom 5.7.0-1-amd64 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: DRI Development , Christian =?iso-8859-1?Q?K=F6nig?= , Jason Gunthorpe Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Sun, Dec 13, 2020 at 04:09:25PM +0100, Thomas Hellstr=F6m (Intel) wrote: > = > On 12/11/20 1:46 PM, Jason Gunthorpe wrote: > > On Fri, Dec 11, 2020 at 08:50:53AM +0100, Thomas Hellstr=F6m (Intel) wr= ote: > > = > > > My understanding of this particular case is that hardware would conti= nue to > > > DMA to orphaned pages that are pinned until the driver is done with > > > DMA, > > mmu notifier replaces pinning as the locking mechanism. Drivers using > > mmu notifier should not be taking pins. > > = > > Keep in mind this was all built for HW with real shadow page tables > > that can do fine grained manipulation. > OK yes, that makes sense and in that context the fence wait is easier to > understand. Looks like for example the radeon driver is using the notifie= r + > get_user_pages() but there it looks like it's used to avoid having > get_user_pages() clash with invalidation. I think the radeon userptr implementation is bad enough that Christian wants to outright remove it. At least he keeps talking about doing that. So maybe not a good example to look at :-) -Daniel > > The GPU version of this to instead manipulate a command queue is a big > > aberration from what was intended. > > = > > Jason > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel -- = 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