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=-3.8 required=3.0 tests=BAYES_00,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 7AE2DC433E4 for ; Wed, 22 Jul 2020 07:12:09 +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 4CE44206F5 for ; Wed, 22 Jul 2020 07:12:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="SkJhztXG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4CE44206F5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ffwll.ch Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id F24A76E5D1; Wed, 22 Jul 2020 07:12:07 +0000 (UTC) Received: from mail-oi1-x241.google.com (mail-oi1-x241.google.com [IPv6:2607:f8b0:4864:20::241]) by gabe.freedesktop.org (Postfix) with ESMTPS id BFFA96E5CC for ; Wed, 22 Jul 2020 07:12:06 +0000 (UTC) Received: by mail-oi1-x241.google.com with SMTP id t4so995992oij.9 for ; Wed, 22 Jul 2020 00:12:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=JwkeYyBomvbYnFOaLpEKlvJ8DzuwKSpH8FekeAKJGLk=; b=SkJhztXGGkVSi+CMtPZ9mnNyIZWb3W+Hi8+3aiJVas3tDxC/kBOhWX+3nnbfTpWlDa 9UwfYCUVg3UUFxW3a9F7GY0tSXLJgK74FxaZAlm/QwZzPlIEgPRh/x41/ptVhbOLyUY4 gUYP4TSQcKLUYmmU2jU3ByYY0yTbp47s9NoiM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=JwkeYyBomvbYnFOaLpEKlvJ8DzuwKSpH8FekeAKJGLk=; b=iliTCLerptW2roOoturX+OIEMx9R1ikbr9gARrF6xQdRLpvu2phzsm64PYK73kOuxh h6VqKXMMB1DcwxPlT7EnTj2F4b2GGoJt3j+JD5SnCtyJ9miBf5nkAfwHFn5cP82zLGu7 v7Efg+noeR2f2clhALxepqFkAmOBTBB6Hkv073oWqf1UF3st1+TYXqhyIksuLGABEpgb V46LKvPcyZu1yQmYg4pIPFX6EJdhmrkmlmC5HBMYirQ0V3HkGJWpWpuYQ+InjrLEsgWh xWxwgzGd4sl/eX0fC9j2+ocIY9XeIqQR5s5JM4IJH00hHCCK+XnUukVP1MDRupnejb15 /Ldw== X-Gm-Message-State: AOAM533l5LH57O4HLqECz8R4r6blcUXgGDkeYM3phxsT4fK1Fx9mqpV0 e68SkhuQaHRF5LhlWU1DYAhFLCpZVO2rVWnVB8gMog== X-Google-Smtp-Source: ABdhPJw79eBtwBgNaIl2ZcTK/cPqRyZb7BtTpgm+YE8+ssCbvckOKoeqxVWT4IlUKWv7BYthNQjzDv0cdeiPNmWCvMQ= X-Received: by 2002:a05:6808:88:: with SMTP id s8mr5710875oic.101.1595401926052; Wed, 22 Jul 2020 00:12:06 -0700 (PDT) MIME-Version: 1.0 References: <20200707201229.472834-4-daniel.vetter@ffwll.ch> <20200709123339.547390-1-daniel.vetter@ffwll.ch> <93b673b7-bb48-96eb-dc2c-bd4f9304000e@shipmail.org> <20200721074157.GB3278063@phenom.ffwll.local> <3603bb71-318b-eb53-0532-9daab62dce86@amd.com> <57a5eb9d-b74f-8ce4-7199-94e911d9b68b@shipmail.org> <805c49b7-f0b3-45dc-5fe3-b352f0971527@shipmail.org> In-Reply-To: <805c49b7-f0b3-45dc-5fe3-b352f0971527@shipmail.org> From: Daniel Vetter Date: Wed, 22 Jul 2020 09:11:55 +0200 Message-ID: To: =?UTF-8?Q?Thomas_Hellstr=C3=B6m_=28Intel=29?= Subject: Re: [Intel-gfx] [Linaro-mm-sig] [PATCH 1/2] dma-buf.rst: Document why indefinite fences are a bad idea X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Felix Kuehling , Daniel Stone , linux-rdma , Intel Graphics Development , DRI Development , "moderated list:DMA BUFFER SHARING FRAMEWORK" , Steve Pronovost , amd-gfx mailing list , Jesse Natalie , Daniel Vetter , Thomas Hellstrom , Linux Media Mailing List , =?UTF-8?Q?Christian_K=C3=B6nig?= , Mika Kuoppala Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" T24gV2VkLCBKdWwgMjIsIDIwMjAgYXQgODo0NSBBTSBUaG9tYXMgSGVsbHN0csO2bSAoSW50ZWwp Cjx0aG9tYXNfb3NAc2hpcG1haWwub3JnPiB3cm90ZToKPgo+Cj4gT24gMjAyMC0wNy0yMiAwMDo0 NSwgRGF2ZSBBaXJsaWUgd3JvdGU6Cj4gPiBPbiBUdWUsIDIxIEp1bCAyMDIwIGF0IDE4OjQ3LCBU aG9tYXMgSGVsbHN0csO2bSAoSW50ZWwpCj4gPiA8dGhvbWFzX29zQHNoaXBtYWlsLm9yZz4gd3Jv dGU6Cj4gPj4KPiA+PiBPbiA3LzIxLzIwIDk6NDUgQU0sIENocmlzdGlhbiBLw7ZuaWcgd3JvdGU6 Cj4gPj4+IEFtIDIxLjA3LjIwIHVtIDA5OjQxIHNjaHJpZWIgRGFuaWVsIFZldHRlcjoKPiA+Pj4+ IE9uIE1vbiwgSnVsIDIwLCAyMDIwIGF0IDAxOjE1OjE3UE0gKzAyMDAsIFRob21hcyBIZWxsc3Ry w7ZtIChJbnRlbCkKPiA+Pj4+IHdyb3RlOgo+ID4+Pj4+IEhpLAo+ID4+Pj4+Cj4gPj4+Pj4gT24g Ny85LzIwIDI6MzMgUE0sIERhbmllbCBWZXR0ZXIgd3JvdGU6Cj4gPj4+Pj4+IENvbWVzIHVwIGV2 ZXJ5IGZldyB5ZWFycywgZ2V0cyBzb21ld2hhdCB0ZWRpb3VzIHRvIGRpc2N1c3MsIGxldCdzCj4g Pj4+Pj4+IHdyaXRlIHRoaXMgZG93biBvbmNlIGFuZCBmb3IgYWxsLgo+ID4+Pj4+Pgo+ID4+Pj4+ PiBXaGF0IEknbSBub3Qgc3VyZSBhYm91dCBpcyB3aGV0aGVyIHRoZSB0ZXh0IHNob3VsZCBiZSBt b3JlIGV4cGxpY2l0IGluCj4gPj4+Pj4+IGZsYXQgb3V0IG1hbmRhdGluZyB0aGUgYW1ka2ZkIGV2 aWN0aW9uIGZlbmNlcyBmb3IgbG9uZyBydW5uaW5nIGNvbXB1dGUKPiA+Pj4+Pj4gd29ya2xvYWRz IG9yIHdvcmtsb2FkcyB3aGVyZSB1c2Vyc3BhY2UgZmVuY2luZyBpcyBhbGxvd2VkLgo+ID4+Pj4+ IEFsdGhvdWdoIChpbiBteSBodW1ibGUgb3BpbmlvbikgaXQgbWlnaHQgYmUgcG9zc2libGUgdG8g Y29tcGxldGVseQo+ID4+Pj4+IHVudGFuZ2xlCj4gPj4+Pj4ga2VybmVsLWludHJvZHVjZWQgZmVu Y2VzIGZvciByZXNvdXJjZSBtYW5hZ2VtZW50IGFuZCBkbWEtZmVuY2VzIHVzZWQKPiA+Pj4+PiBm b3IKPiA+Pj4+PiBjb21wbGV0aW9uLSBhbmQgZGVwZW5kZW5jeSB0cmFja2luZyBhbmQgbGlmdCBh IGxvdCBvZiByZXN0cmljdGlvbnMKPiA+Pj4+PiBmb3IgdGhlCj4gPj4+Pj4gZG1hLWZlbmNlcywg aW5jbHVkaW5nIHByb2hpYml0aW5nIGluZmluaXRlIG9uZXMsIEkgdGhpbmsgdGhpcyBtYWtlcwo+ ID4+Pj4+IHNlbnNlCj4gPj4+Pj4gZGVzY3JpYmluZyB0aGUgY3VycmVudCBzdGF0ZS4KPiA+Pj4+ IFllYWggSSB0aGluayBhIGZ1dHVyZSBwYXRjaCBuZWVkcyB0byB0eXBlIHVwIGhvdyB3ZSB3YW50 IHRvIG1ha2UgdGhhdAo+ID4+Pj4gaGFwcGVuIChmb3Igc29tZSBjcm9zcyBkcml2ZXIgY29uc2lz dGVuY3kpIGFuZCB3aGF0IG5lZWRzIHRvIGJlCj4gPj4+PiBjb25zaWRlcmVkLiBTb21lIG9mIHRo ZSBuZWNlc3NhcnkgcGFydHMgYXJlIGFscmVhZHkgdGhlcmUgKHdpdGggbGlrZSB0aGUKPiA+Pj4+ IHByZWVtcHRpb24gZmVuY2VzIGFtZGtmZCBoYXMgYXMgYW4gZXhhbXBsZSksIGJ1dCBJIHRoaW5r IHNvbWUgY2xlYXIgZG9jcwo+ID4+Pj4gb24gd2hhdCdzIHJlcXVpcmVkIGZyb20gYm90aCBodywg ZHJpdmVycyBhbmQgdXNlcnNwYWNlIHdvdWxkIGJlIHJlYWxseQo+ID4+Pj4gZ29vZC4KPiA+Pj4g SSdtIGN1cnJlbnRseSB3cml0aW5nIHRoYXQgdXAsIGJ1dCBwcm9iYWJseSBzdGlsbCBuZWVkIGEg ZmV3IGRheXMgZm9yCj4gPj4+IHRoaXMuCj4gPj4gR3JlYXQhIEkgcHV0IGRvd24gc29tZSAodmVy eSkgaW5pdGlhbCB0aG91Z2h0cyBhIGNvdXBsZSBvZiB3ZWVrcyBhZ28KPiA+PiBidWlsZGluZyBv biBldmljdGlvbiBmZW5jZXMgZm9yIHZhcmlvdXMgaGFyZHdhcmUgY29tcGxleGl0eSBsZXZlbHMg aGVyZToKPiA+Pgo+ID4+IGh0dHBzOi8vZ2l0bGFiLmZyZWVkZXNrdG9wLm9yZy90aG9tYXNoL2Rv Y3MvLS9ibG9iL21hc3Rlci9VbnRhbmdsaW5nJTIwZG1hLWZlbmNlJTIwYW5kJTIwbWVtb3J5JTIw YWxsb2NhdGlvbi5vZHQKPiA+IFdlIGFyZSBzZWVpbmcgSFcgdGhhdCBoYXMgcmVjb3ZlcmFibGUg R1BVIHBhZ2UgZmF1bHRzIGJ1dCBvbmx5IGZvcgo+ID4gY29tcHV0ZSB0YXNrcywgYW5kIHNjaGVk dWxlciB3aXRob3V0IHNlbWFwaG9yZXMgaHcgZm9yIGdyYXBoaWNzLgo+ID4KPiA+IFNvIGEgc2lu Z2xlIGRyaXZlciBtYXkgaGF2ZSB0byBleHBvc2UgYm90aCBtb2RlbHMgdG8gdXNlcnNwYWNlIGFu ZAo+ID4gYWxzbyBpbnRyb2R1Y2VzIHRoZSBwcm9ibGVtIG9mIGhvdyB0byBpbnRlcm9wZXJhdGUg YmV0d2VlbiB0aGUgdHdvCj4gPiBtb2RlbHMgb24gb25lIGNhcmQuCj4gPgo+ID4gRGF2ZS4KPgo+ IEhtbSwgeWVzIHRvIGJlZ2luIHdpdGggaXQncyBpbXBvcnRhbnQgdG8gbm90ZSB0aGF0IHRoaXMg aXMgbm90IGEKPiByZXBsYWNlbWVudCBmb3IgbmV3IHByb2dyYW1taW5nIG1vZGVscyBvciBBUElz LCBUaGlzIGlzIHNvbWV0aGluZyB0aGF0Cj4gdGFrZXMgcGxhY2UgaW50ZXJuYWxseSBpbiBkcml2 ZXJzIHRvIG1pdGlnYXRlIG1hbnkgb2YgdGhlIHJlc3RyaWN0aW9ucwo+IHRoYXQgYXJlIGN1cnJl bnRseSBpbXBvc2VkIG9uIGRtYS1mZW5jZSBhbmQgZG9jdW1lbnRlZCBpbiB0aGlzIGFuZAo+IHBy ZXZpb3VzIHNlcmllcy4gSXQncyBiYXNpY2FsbHkgdGhlIGRyaXZlci1wcml2YXRlIG5hcnJvdyBj b21wbGV0aW9ucwo+IEphc29uIHN1Z2dlc3RlZCBpbiB0aGUgbG9ja2RlcCBwYXRjaGVzIGRpc2N1 c3Npb25zIGltcGxlbWVudGVkIHRoZSBzYW1lCj4gd2F5IGFzIGV2aWN0aW9uLWZlbmNlcy4KPgo+ IFRoZSBtZW1vcnkgZmVuY2UgQVBJIHdvdWxkIGJlIGxvY2FsIHRvIGhlbHBlcnMgYW5kIG1pZGRs ZS1sYXllcnMgbGlrZQo+IFRUTSwgYW5kIHRoZSBjb3JyZXNwb25kaW5nIGRyaXZlcnMuICBUaGUg b25seSBjcm9zcy1kcml2ZXItbGlrZQo+IHZpc2liaWxpdHkgd291bGQgYmUgdGhhdCB0aGUgZG1h LWJ1ZiBtb3ZlX25vdGlmeSgpIGNhbGxiYWNrIHdvdWxkIG5vdCBiZQo+IGFsbG93ZWQgdG8gd2Fp dCBvbiBkbWEtZmVuY2VzIG9yIHNvbWV0aGluZyB0aGF0IGRlcGVuZHMgb24gYSBkbWEtZmVuY2Uu CgpCZWNhdXNlIHdlIGNhbid0IHByZWVtcHQgKG9uIHNvbWUgZW5naW5lcyBhdCBsZWFzdCkgd2Ug YWxyZWFkeSBoYXZlCnRoZSByZXF1aXJlbWVudCB0aGF0IGNyb3NzIGRyaXZlciBidWZmZXIgbWFu YWdlbWVudCBjYW4gZ2V0IHN0dWNrIG9uIGEKZG1hLWZlbmNlLiBOb3QgZXZlbiB0YWtpbmcgaW50 byBhY2NvdW50IHRoZSBob3Jyb3JzIHdlIGRvIHdpdGgKdXNlcnB0ciwgd2hpY2ggYXJlIGNyb3Nz IGRyaXZlciBubyBtYXR0ZXIgd2hhdC4gTGltaXRpbmcgbW92ZV9ub3RpZnkKdG8gbWVtb3J5IGZl bmNlcyBvbmx5IGRvZXNuJ3Qgd29yaywgc2luY2UgdGhlIHB0ZSBjbGVhcmluZyBtaWdodCBuZWVk CnRvIHdhaXQgZm9yIGEgZG1hX2ZlbmNlIGZpcnN0LiBIZW5jZSB0aGlzIGJlY29tZXMgYSBmdWxs IGVuZC1vZi1iYXRjaApmZW5jZSwgbm90IGp1c3QgYSBsaW1pdGVkIGtlcm5lbC1pbnRlcm5hbCBt ZW1vcnkgZmVuY2UuCgpUaGF0J3Mga2luZGEgd2h5IEkgdGhpbmsgb25seSByZWFzb25hYmxlIG9w dGlvbiBpcyB0byB0b3NzIGluIHRoZQp0b3dlbCBhbmQgZGVjbGFyZSBkbWEtZmVuY2UgdG8gYmUg dGhlIG1lbW9yeSBmZW5jZSAoYW5kIHN1Y2sgdXAgYWxsCnRoZSBjb25zZXF1ZW5jZXMgb2YgdGhh dCBkZWNpc2lvbiBhcyB1YXBpLCB3aGljaCBpcyBraW5kYSB3aGVyZSB3ZQphcmUpLCBhbmQgY29u c3RydWN0IHNvbWV0aGluZyBuZXcmZW50aXJlbHkgZnJlZS13aGVlbGluZyBmb3IgdXNlcnNwYWNl CmZlbmNpbmcuIEJ1dCBvbmx5IGZvciBlbmdpbmVzIHRoYXQgYWxsb3cgZW5vdWdoIHByZWVtcHQv Z3B1IHBhZ2UKZmF1bHRpbmcgdG8gbWFrZSB0aGF0IHBvc3NpYmxlLiBGcmVlIHdoZWVsaW5nIHVz ZXJzcGFjZSBmZW5jZXMvZ3B1CnNlbWFwaG9yZXMgb3Igd2hhdGV2ZXIgeW91IHdhbnQgdG8gY2Fs bCB0aGVtIChvbiB3aW5kb3dzIEkgdGhpbmsgaXQncwptb25pdG9yZWQgZmVuY2UpIG9ubHkgd29y ayBpZiB5b3UgY2FuIHByZWVtcHQgdG8gZGVjb3VwbGUgdGhlIG1lbW9yeQpmZW5jZXMgZnJvbSB5 b3VyIGdwdSBjb21tYW5kIGV4ZWN1dGlvbi4KClRoZXJlJ3MgdGhlIGluLWJldHdlZW4gc3RlcCBv ZiBqdXN0IGRlY291cGxpbmcgdGhlIGJhdGNoYnVmZmVyCnN1Ym1pc3Npb24gcHJlcCBmb3IgaHcg d2l0aG91dCBhbnkgcHJlZW1wdCAoYnV0IGEgc2NoZWR1bGVyKSwgYnV0IHRoYXQKc2VlbXMga2lu ZGEgcG9pbnRsZXNzLiBNb2Rlcm4gZXhlY2J1ZiBzaG91bGQgYmUgTygxKSBmYXN0cGF0aCwgd2l0 aAphbGwgdGhlIGFsbG9jYXRpb24vbWFwcGluZyB3b3JrIHB1bGxlZCBvdXQgYWhlYWQuIHZrIGV4 cG9zZXMgdGhhdAptb2RlbCBkaXJlY3RseSB0byBjbGllbnRzLCBHTCBkcml2ZXJzIGNvdWxkIHVz ZSBpdCBpbnRlcm5hbGx5IHRvbywgc28KSSBzZWUgemVybyB2YWx1ZSBpbiBzcGVuZGluZyBsb3Rz IG9mIHRpbWUgZW5naW5lZXJpbmcgdmVyeSB0cmlja3kKa2VybmVsIGNvZGUganVzdCBmb3Igb2xk IHVzZXJzcGFjZS4gTXVjaCBtb3JlIHJlYXNvbmFibGUgdG8gZG8gdGhhdCBpbgp1c2Vyc3BhY2Us IHdoZXJlIHdlIGhhdmUgcmVhbCBkZWJ1Z2dlcnMgYW5kIG5vIHBhbmljcyBhYm91dCBzZWN1cml0 eQpidWdzIChvciB3ZWxsLCBhIGxvdCBsZXNzLCB3ZWJnbCBpcyBzdGlsbCBhIHRoaW5nLCBidXQg YXQgbGVhc3QKYnJvd3NlcnMgcmVhbGl6ZWQgeW91IG5lZWQgdG8gY29udGFpbmVyIHRoYXQgY29t cGxldGVseSkuCgpDaGVlcnMsIERhbmllbAoKPiBTbyB3aXRoIHRoYXQgaW4gbWluZCwgSSBkb24n dCBmb3Jlc2VlIGVuZ2luZXMgd2l0aCBkaWZmZXJlbnQKPiBjYXBhYmlsaXRpZXMgb24gdGhlIHNh bWUgY2FyZCBiZWluZyBhIHByb2JsZW0uCj4KPiAvVGhvbWFzCj4KPgoKCi0tIApEYW5pZWwgVmV0 dGVyClNvZnR3YXJlIEVuZ2luZWVyLCBJbnRlbCBDb3Jwb3JhdGlvbgpodHRwOi8vYmxvZy5mZnds bC5jaApfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpJbnRl bC1nZnggbWFpbGluZyBsaXN0CkludGVsLWdmeEBsaXN0cy5mcmVlZGVza3RvcC5vcmcKaHR0cHM6 Ly9saXN0cy5mcmVlZGVza3RvcC5vcmcvbWFpbG1hbi9saXN0aW5mby9pbnRlbC1nZngK