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=-9.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 B19B6C433E3 for ; Thu, 9 Jul 2020 12:33:55 +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 87B1F20708 for ; Thu, 9 Jul 2020 12:33:55 +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="FT1zeqK0" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 87B1F20708 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 9F97A6EA60; Thu, 9 Jul 2020 12:33:53 +0000 (UTC) Received: from mail-wm1-x341.google.com (mail-wm1-x341.google.com [IPv6:2a00:1450:4864:20::341]) by gabe.freedesktop.org (Postfix) with ESMTPS id 894506E42F for ; Thu, 9 Jul 2020 12:33:52 +0000 (UTC) Received: by mail-wm1-x341.google.com with SMTP id g10so6175510wmc.1 for ; Thu, 09 Jul 2020 05:33:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=9ml7yu61orPGiyeLHj7KPJdBGRuwIj4VGf7RIdg6+6E=; b=FT1zeqK0F6re7x3hxU6WuwKnuhLdZTTGsE6uj0ZmBrbf9TVkVqTK3LOGBYbBEjYddX UQxsmufvcNCR+EiwLcPUmPYWFaC5pZ5CGfGNvzGthBXT2lli8Ur+GfzSgeLxXbdC//jm w7Dqku33+bwbEzRQvB6e/WItr0k784kTvA0/0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=9ml7yu61orPGiyeLHj7KPJdBGRuwIj4VGf7RIdg6+6E=; b=nnKxmk/M/FZbPu8jFGT+g8s7H0PchXXX9Oywzx8neybZ2eZudKFOjqlPqMdQs0TPId gWYAaI/BooNqJH6ipbCpeS5+7/htn3Zv27gwBYonWgR+yP8Z3Y3xFFoy8Bu3lcOEHiZl di42efE/DJHkikMxV2cCTsY9camhXebFtGRK/bA8BUGwThHivtnRzp6Dk23lUpkuNl0Q MikgwKsTeDEiggjMIQ5FiPsZtRbMKXBWuimbf6mTovt+Dn292PJYtEpy59Zqq+GLhUE5 FTJiIsfkTbLLqQbiw0RMq7383hfbQu/oS0vNpQTPAXFUG3uOjjlRIQu5k2NX8GWOjBXS RcvQ== X-Gm-Message-State: AOAM533CcBhOJb9JshYPeBwDgW4yilQAgATH64YB85BFMzy5Ja+3NZfn WCh7dJzXSp0EirmFwbpq9QQb5gwTbj0= X-Google-Smtp-Source: ABdhPJyW1X39siqvN1tXyO+a5xJDhtYxZB7qgF8t/3W1eiXrhQsMLgXCOAKI1Lx9mgsJn2P0+ZV+SQ== X-Received: by 2002:a7b:c313:: with SMTP id k19mr14181981wmj.67.1594298030902; Thu, 09 Jul 2020 05:33:50 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id o205sm4925347wme.24.2020.07.09.05.33.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Jul 2020 05:33:50 -0700 (PDT) From: Daniel Vetter To: DRI Development Subject: [PATCH 1/2] dma-buf.rst: Document why indefinite fences are a bad idea Date: Thu, 9 Jul 2020 14:33:38 +0200 Message-Id: <20200709123339.547390-1-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200707201229.472834-4-daniel.vetter@ffwll.ch> References: <20200707201229.472834-4-daniel.vetter@ffwll.ch> MIME-Version: 1.0 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: Daniel Stone , linux-rdma@vger.kernel.org, Daniel Vetter , Intel Graphics Development , amd-gfx@lists.freedesktop.org, Chris Wilson , linaro-mm-sig@lists.linaro.org, Steve Pronovost , Daniel Vetter , Jason Ekstrand , Jesse Natalie , Felix Kuehling , Thomas Hellstrom , linux-media@vger.kernel.org, =?UTF-8?q?Christian=20K=C3=B6nig?= , Mika Kuoppala Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Q29tZXMgdXAgZXZlcnkgZmV3IHllYXJzLCBnZXRzIHNvbWV3aGF0IHRlZGlvdXMgdG8gZGlzY3Vz cywgbGV0J3MKd3JpdGUgdGhpcyBkb3duIG9uY2UgYW5kIGZvciBhbGwuCgpXaGF0IEknbSBub3Qg c3VyZSBhYm91dCBpcyB3aGV0aGVyIHRoZSB0ZXh0IHNob3VsZCBiZSBtb3JlIGV4cGxpY2l0IGlu CmZsYXQgb3V0IG1hbmRhdGluZyB0aGUgYW1ka2ZkIGV2aWN0aW9uIGZlbmNlcyBmb3IgbG9uZyBy dW5uaW5nIGNvbXB1dGUKd29ya2xvYWRzIG9yIHdvcmtsb2FkcyB3aGVyZSB1c2Vyc3BhY2UgZmVu Y2luZyBpcyBhbGxvd2VkLgoKdjI6IE5vdyB3aXRoIGRvdCBncmFwaCEKCnYzOiBUeXBvIChEYXZl IEFpcmxpZSkKCkFja2VkLWJ5OiBDaHJpc3RpYW4gS8O2bmlnIDxjaHJpc3RpYW4ua29lbmlnQGFt ZC5jb20+CkFja2VkLWJ5OiBEYW5pZWwgU3RvbmUgPGRhbmllbHNAY29sbGFib3JhLmNvbT4KQ2M6 IEplc3NlIE5hdGFsaWUgPGplbmF0YWxpQG1pY3Jvc29mdC5jb20+CkNjOiBTdGV2ZSBQcm9ub3Zv c3QgPHNwcm9ub3ZvQG1pY3Jvc29mdC5jb20+CkNjOiBKYXNvbiBFa3N0cmFuZCA8amFzb25Aamxl a3N0cmFuZC5uZXQ+CkNjOiBGZWxpeCBLdWVobGluZyA8RmVsaXguS3VlaGxpbmdAYW1kLmNvbT4K Q2M6IE1pa2EgS3VvcHBhbGEgPG1pa2Eua3VvcHBhbGFAaW50ZWwuY29tPgpDYzogVGhvbWFzIEhl bGxzdHJvbSA8dGhvbWFzLmhlbGxzdHJvbUBpbnRlbC5jb20+CkNjOiBsaW51eC1tZWRpYUB2Z2Vy Lmtlcm5lbC5vcmcKQ2M6IGxpbmFyby1tbS1zaWdAbGlzdHMubGluYXJvLm9yZwpDYzogbGludXgt cmRtYUB2Z2VyLmtlcm5lbC5vcmcKQ2M6IGFtZC1nZnhAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCkNj OiBpbnRlbC1nZnhAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCkNjOiBDaHJpcyBXaWxzb24gPGNocmlz QGNocmlzLXdpbHNvbi5jby51az4KQ2M6IE1hYXJ0ZW4gTGFua2hvcnN0IDxtYWFydGVuLmxhbmto b3JzdEBsaW51eC5pbnRlbC5jb20+CkNjOiBDaHJpc3RpYW4gS8O2bmlnIDxjaHJpc3RpYW4ua29l bmlnQGFtZC5jb20+ClNpZ25lZC1vZmYtYnk6IERhbmllbCBWZXR0ZXIgPGRhbmllbC52ZXR0ZXJA aW50ZWwuY29tPgotLS0KIERvY3VtZW50YXRpb24vZHJpdmVyLWFwaS9kbWEtYnVmLnJzdCB8IDcw ICsrKysrKysrKysrKysrKysrKysrKysrKysrKysKIDEgZmlsZSBjaGFuZ2VkLCA3MCBpbnNlcnRp b25zKCspCgpkaWZmIC0tZ2l0IGEvRG9jdW1lbnRhdGlvbi9kcml2ZXItYXBpL2RtYS1idWYucnN0 IGIvRG9jdW1lbnRhdGlvbi9kcml2ZXItYXBpL2RtYS1idWYucnN0CmluZGV4IGY4ZjZkZWNkZTM1 OS4uMTAwYmZkMjI3MjY1IDEwMDY0NAotLS0gYS9Eb2N1bWVudGF0aW9uL2RyaXZlci1hcGkvZG1h LWJ1Zi5yc3QKKysrIGIvRG9jdW1lbnRhdGlvbi9kcml2ZXItYXBpL2RtYS1idWYucnN0CkBAIC0x NzgsMyArMTc4LDczIEBAIERNQSBGZW5jZSB1QUJJL1N5bmMgRmlsZQogLi4ga2VybmVsLWRvYzo6 IGluY2x1ZGUvbGludXgvc3luY19maWxlLmgKICAgIDppbnRlcm5hbDoKIAorSW5kZWZpbml0ZSBE TUEgRmVuY2VzCit+fn5+fn5+fn5+fn5+fn5+fn5+fgorCitBdCB2YXJpb3VzIHRpbWVzICZkbWFf ZmVuY2Ugd2l0aCBhbiBpbmRlZmluaXRlIHRpbWUgdW50aWwgZG1hX2ZlbmNlX3dhaXQoKQorZmlu aXNoZXMgaGF2ZSBiZWVuIHByb3Bvc2VkLiBFeGFtcGxlcyBpbmNsdWRlOgorCisqIEZ1dHVyZSBm ZW5jZXMsIHVzZWQgaW4gSFdDMSB0byBzaWduYWwgd2hlbiBhIGJ1ZmZlciBpc24ndCB1c2VkIGJ5 IHRoZSBkaXNwbGF5CisgIGFueSBsb25nZXIsIGFuZCBjcmVhdGVkIHdpdGggdGhlIHNjcmVlbiB1 cGRhdGUgdGhhdCBtYWtlcyB0aGUgYnVmZmVyIHZpc2libGUuCisgIFRoZSB0aW1lIHRoaXMgZmVu Y2UgY29tcGxldGVzIGlzIGVudGlyZWx5IHVuZGVyIHVzZXJzcGFjZSdzIGNvbnRyb2wuCisKKyog UHJveHkgZmVuY2VzLCBwcm9wb3NlZCB0byBoYW5kbGUgJmRybV9zeW5jb2JqIGZvciB3aGljaCB0 aGUgZmVuY2UgaGFzIG5vdCB5ZXQKKyAgYmVlbiBzZXQuIFVzZWQgdG8gYXN5bmNocm9ub3VzbHkg ZGVsYXkgY29tbWFuZCBzdWJtaXNzaW9uLgorCisqIFVzZXJzcGFjZSBmZW5jZXMgb3IgZ3B1IGZ1 dGV4ZXMsIGZpbmUtZ3JhaW5lZCBsb2NraW5nIHdpdGhpbiBhIGNvbW1hbmQgYnVmZmVyCisgIHRo YXQgdXNlcnNwYWNlIHVzZXMgZm9yIHN5bmNocm9uaXphdGlvbiBhY3Jvc3MgZW5naW5lcyBvciB3 aXRoIHRoZSBDUFUsIHdoaWNoCisgIGFyZSB0aGVuIGltcG9ydGVkIGFzIGEgRE1BIGZlbmNlIGZv ciBpbnRlZ3JhdGlvbiBpbnRvIGV4aXN0aW5nIHdpbnN5cworICBwcm90b2NvbHMuCisKKyogTG9u Zy1ydW5uaW5nIGNvbXB1dGUgY29tbWFuZCBidWZmZXJzLCB3aGlsZSBzdGlsbCB1c2luZyB0cmFk aXRpb25hbCBlbmQgb2YKKyAgYmF0Y2ggRE1BIGZlbmNlcyBmb3IgbWVtb3J5IG1hbmFnZW1lbnQg aW5zdGVhZCBvZiBjb250ZXh0IHByZWVtcHRpb24gRE1BCisgIGZlbmNlcyB3aGljaCBnZXQgcmVh dHRhY2hlZCB3aGVuIHRoZSBjb21wdXRlIGpvYiBpcyByZXNjaGVkdWxlZC4KKworQ29tbW9uIHRv IGFsbCB0aGVzZSBzY2hlbWVzIGlzIHRoYXQgdXNlcnNwYWNlIGNvbnRyb2xzIHRoZSBkZXBlbmRl bmNpZXMgb2YgdGhlc2UKK2ZlbmNlcyBhbmQgY29udHJvbHMgd2hlbiB0aGV5IGZpcmUuIE1peGlu ZyBpbmRlZmluaXRlIGZlbmNlcyB3aXRoIG5vcm1hbAoraW4ta2VybmVsIERNQSBmZW5jZXMgZG9l cyBub3Qgd29yaywgZXZlbiB3aGVuIGEgZmFsbGJhY2sgdGltZW91dCBpcyBpbmNsdWRlZCB0bwor cHJvdGVjdCBhZ2FpbnN0IG1hbGljaW91cyB1c2Vyc3BhY2U6CisKKyogT25seSB0aGUga2VybmVs IGtub3dzIGFib3V0IGFsbCBETUEgZmVuY2UgZGVwZW5kZW5jaWVzLCB1c2Vyc3BhY2UgaXMgbm90 IGF3YXJlCisgIG9mIGRlcGVuZGVuY2llcyBpbmplY3RlZCBkdWUgdG8gbWVtb3J5IG1hbmFnZW1l bnQgb3Igc2NoZWR1bGVyIGRlY2lzaW9ucy4KKworKiBPbmx5IHVzZXJzcGFjZSBrbm93cyBhYm91 dCBhbGwgZGVwZW5kZW5jaWVzIGluIGluZGVmaW5pdGUgZmVuY2VzIGFuZCB3aGVuCisgIGV4YWN0 bHkgdGhleSB3aWxsIGNvbXBsZXRlLCB0aGUga2VybmVsIGhhcyBubyB2aXNpYmlsaXR5LgorCitG dXJ0aGVybW9yZSB0aGUga2VybmVsIGhhcyB0byBiZSBhYmxlIHRvIGhvbGQgdXAgdXNlcnNwYWNl IGNvbW1hbmQgc3VibWlzc2lvbgorZm9yIG1lbW9yeSBtYW5hZ2VtZW50IG5lZWRzLCB3aGljaCBt ZWFucyB3ZSBtdXN0IHN1cHBvcnQgaW5kZWZpbml0ZSBmZW5jZXMgYmVpbmcKK2RlcGVuZGVudCB1 cG9uIERNQSBmZW5jZXMuIElmIHRoZSBrZXJuZWwgYWxzbyBzdXBwb3J0IGluZGVmaW5pdGUgZmVu Y2VzIGluIHRoZQora2VybmVsIGxpa2UgYSBETUEgZmVuY2UsIGxpa2UgYW55IG9mIHRoZSBhYm92 ZSBwcm9wb3NhbCB3b3VsZCwgdGhlcmUgaXMgdGhlCitwb3RlbnRpYWwgZm9yIGRlYWRsb2Nrcy4K KworLi4ga2VybmVsLXJlbmRlcjo6IERPVAorICAgOmFsdDogSW5kZWZpbml0ZSBGZW5jaW5nIERl cGVuZGVuY3kgQ3ljbGUKKyAgIDpjYXB0aW9uOiBJbmRlZmluaXRlIEZlbmNpbmcgRGVwZW5kZW5j eSBDeWNsZQorCisgICBkaWdyYXBoICJGZW5jaW5nIEN5Y2xlIiB7CisgICAgICBub2RlIFtzaGFw ZT1ib3ggYmdjb2xvcj1ncmV5IHN0eWxlPWZpbGxlZF0KKyAgICAgIGtlcm5lbCBbbGFiZWw9Iktl cm5lbCBETUEgRmVuY2VzIl0KKyAgICAgIHVzZXJzcGFjZSBbbGFiZWw9InVzZXJzcGFjZSBjb250 cm9sbGVkIGZlbmNlcyJdCisgICAgICBrZXJuZWwgLT4gdXNlcnNwYWNlIFtsYWJlbD0ibWVtb3J5 IG1hbmFnZW1lbnQiXQorICAgICAgdXNlcnNwYWNlIC0+IGtlcm5lbCBbbGFiZWw9IkZ1dHVyZSBm ZW5jZSwgZmVuY2UgcHJveHksIC4uLiJdCisKKyAgICAgIHsgcmFuaz1zYW1lOyBrZXJuZWwgdXNl cnNwYWNlIH0KKyAgIH0KKworVGhpcyBtZWFucyB0aGF0IHRoZSBrZXJuZWwgbWlnaHQgYWNjaWRl bnRhbGx5IGNyZWF0ZSBkZWFkbG9ja3MKK3Rocm91Z2ggbWVtb3J5IG1hbmFnZW1lbnQgZGVwZW5k ZW5jaWVzIHdoaWNoIHVzZXJzcGFjZSBpcyB1bmF3YXJlIG9mLCB3aGljaAorcmFuZG9tbHkgaGFu Z3Mgd29ya2xvYWRzIHVudGlsIHRoZSB0aW1lb3V0IGtpY2tzIGluLiBXb3JrbG9hZHMsIHdoaWNo IGZyb20KK3VzZXJzcGFjZSdzIHBlcnNwZWN0aXZlLCBkbyBub3QgY29udGFpbiBhIGRlYWRsb2Nr LiAgSW4gc3VjaCBhIG1peGVkIGZlbmNpbmcKK2FyY2hpdGVjdHVyZSB0aGVyZSBpcyBubyBzaW5n bGUgZW50aXR5IHdpdGgga25vd2xlZGdlIG9mIGFsbCBkZXBlbmRlbmNpZXMuCitUaGVmb3JlIHBy ZXZlbnRpbmcgc3VjaCBkZWFkbG9ja3MgZnJvbSB3aXRoaW4gdGhlIGtlcm5lbCBpcyBub3QgcG9z c2libGUuCisKK1RoZSBvbmx5IHNvbHV0aW9uIHRvIGF2b2lkIGRlcGVuZGVuY2llcyBsb29wcyBp cyBieSBub3QgYWxsb3dpbmcgaW5kZWZpbml0ZQorZmVuY2VzIGluIHRoZSBrZXJuZWwuIFRoaXMg bWVhbnM6CisKKyogTm8gZnV0dXJlIGZlbmNlcywgcHJveHkgZmVuY2VzIG9yIHVzZXJzcGFjZSBm ZW5jZXMgaW1wb3J0ZWQgYXMgRE1BIGZlbmNlcywKKyAgd2l0aCBvciB3aXRob3V0IGEgdGltZW91 dC4KKworKiBObyBETUEgZmVuY2VzIHRoYXQgc2lnbmFsIGVuZCBvZiBiYXRjaGJ1ZmZlciBmb3Ig Y29tbWFuZCBzdWJtaXNzaW9uIHdoZXJlCisgIHVzZXJzcGFjZSBpcyBhbGxvd2VkIHRvIHVzZSB1 c2Vyc3BhY2UgZmVuY2luZyBvciBsb25nIHJ1bm5pbmcgY29tcHV0ZQorICB3b3JrbG9hZHMuIFRo aXMgYWxzbyBtZWFucyBubyBpbXBsaWNpdCBmZW5jaW5nIGZvciBzaGFyZWQgYnVmZmVycyBpbiB0 aGVzZQorICBjYXNlcy4KLS0gCjIuMjcuMAoKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX18KZHJpLWRldmVsIG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMu ZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlzdHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlz dGluZm8vZHJpLWRldmVsCg==