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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 340EEC433E0 for ; Mon, 18 May 2020 08:24:05 +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 04D6D20674 for ; Mon, 18 May 2020 08:24:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="dcE2zK93" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 04D6D20674 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com 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 765C86E12C; Mon, 18 May 2020 08:24:04 +0000 (UTC) Received: from us-smtp-delivery-1.mimecast.com (us-smtp-2.mimecast.com [205.139.110.61]) by gabe.freedesktop.org (Postfix) with ESMTPS id 553496E12C for ; Mon, 18 May 2020 08:24:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1589790242; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=vi1MWfSX1gmTbxPq7f6vfW3/wyZU7SIZx/TfRTQP8ok=; b=dcE2zK93azVarlJKV28QYrfXk7Pqr8gdKtqbPKPB6db1YoWzmYXcg9zCTwA9PpEJuTH2dk km4Uu6+lZ759PpV+3IjFl5lW+S5cpT/pi/5Sjqegv0XKdExxzR5Yg8NrwgClKrHs+S/ajy TtLTouAFX5WQwW6ttDzHeYd0FPXrMzs= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-180-nOAARt11NpWU16UnjSuxsw-1; Mon, 18 May 2020 04:23:58 -0400 X-MC-Unique: nOAARt11NpWU16UnjSuxsw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 82B7880B725; Mon, 18 May 2020 08:23:56 +0000 (UTC) Received: from sirius.home.kraxel.org (ovpn-113-50.ams2.redhat.com [10.36.113.50]) by smtp.corp.redhat.com (Postfix) with ESMTP id C9C2F1001B2C; Mon, 18 May 2020 08:23:55 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id 596FD17444; Mon, 18 May 2020 10:23:54 +0200 (CEST) Date: Mon, 18 May 2020 10:23:54 +0200 From: Gerd Hoffmann To: Thomas Zimmermann Subject: Re: [PATCH 1/2] drm/shmem: Use cached mappings by default Message-ID: <20200518082354.jeuyt7uzek73pjkp@sirius.home.kraxel.org> References: <20200513150312.21421-1-tzimmermann@suse.de> <20200513150312.21421-2-tzimmermann@suse.de> <20200514124050.GV206103@phenom.ffwll.local> <6cec8a8a-d642-cd93-906a-eafab49a12d7@suse.de> <20200515141044.GH206103@phenom.ffwll.local> <3e09cc7d-c609-e10a-3fe9-f40f3bbfaeaf@suse.de> MIME-Version: 1.0 In-Reply-To: <3e09cc7d-c609-e10a-3fe9-f40f3bbfaeaf@suse.de> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline 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: David Airlie , Sean Paul , Emil Velikov , dri-devel , Sam Ravnborg Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" > > $ git grep drm_gem_shmem_mmap > > > > We also need correct access from userspace, otherwise the gpu is going to > > be sad. > > I've been thinking about this, and I think it means that we can never > have cached mappings anywhere. Even if shmem supports it internally for > most drivers, as soon as the page are exported, the importer could > expect uncached memory. The importer should not expect anything but call dma-buf ops so the exporter has a chance to handle this correctly. (Yes, we don't get this right everywhere, some drivers take the dma-bufs list of pages and do their own thing ...). take care, Gerd _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel