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=-0.7 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, 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 80FC2C433E0 for ; Thu, 9 Jul 2020 07:36:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5CB382070E for ; Thu, 9 Jul 2020 07:36:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=fooishbar-org.20150623.gappssmtp.com header.i=@fooishbar-org.20150623.gappssmtp.com header.b="q1a8xJM/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726270AbgGIHg4 (ORCPT ); Thu, 9 Jul 2020 03:36:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39310 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726269AbgGIHg4 (ORCPT ); Thu, 9 Jul 2020 03:36:56 -0400 Received: from mail-wr1-x442.google.com (mail-wr1-x442.google.com [IPv6:2a00:1450:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B2619C08C5CE for ; Thu, 9 Jul 2020 00:36:55 -0700 (PDT) Received: by mail-wr1-x442.google.com with SMTP id f2so1216789wrp.7 for ; Thu, 09 Jul 2020 00:36:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fooishbar-org.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=KKtQly4ao6B6nwRWEDkHlPwVhDZwmTFzlBzK230IGUs=; b=q1a8xJM/Q9Wj785BtNlEuDFVR1eQk54JebnUrlGorLvEHVMtqdFOuaGKrTYCsphJ1h jdn7d6bEOoYqm6Dc8k5LjNzJMPs7sqOYl93W/0yr7CIrm1h2/Lv3g+fhNpsEY21yKMZh ju/lEovQ160zqDVi53k34kcqcJLZdTHFacxSS0a8W4cpfdDptcuxHSPlubyxOMMuaSBC zAyYruzxGOJbmMUqmjN2Chf/XWhBZgAcu1tmI7ShCPPddj04M/M8Yf8LAduuKxgJQlTV rIzd0KYtUf5G7qRV/73bX9CHJ9uhQaanPFGitTqRJCgzv1EMfeBg/7UHJHVTRmYqPihB A8cg== 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; bh=KKtQly4ao6B6nwRWEDkHlPwVhDZwmTFzlBzK230IGUs=; b=CaSPvT6cPOl7vsy0mjW+VbQKpXQGo7GKy16cGKrslpaZrSXzpmaXOV2GcdHlSmhfEs 0If9caun9pwvrc+RLVx2WFnwVtJDlPCAgTPfEc/U8EA4uWAi3Tm1kDD0iUUyZPcVuab6 LhWhEwBP/9plVvfdr1hJ86/fh45bcWuCfjm/C37kvfvo3UuNFb7n3381Uh1BxeJ5xBlp aPDmnQXDAH6maixTfBrWTXV1/rL24Kp2KDKTSZTHELk8DxLZcKXOfAL5/BpCoFBYRfV8 TP9fRRy50d5E/OEN0tOAkeQdOh2yK2VNZM93KrQpCai5eTWkRXgNNmeyMgCwBG7gFacW V4aw== X-Gm-Message-State: AOAM532UF6w/kUuB9yLzPew6twQPXpOM/7zy2cLEVMbWF6hEly50dDsO PH4NekKdYsuBvBmYuX8PtnCtSZaBkccNDSA5eKc5kQ== X-Google-Smtp-Source: ABdhPJwOIE8GoaZZk1aSRinMLKGhWIbTpQIZ0IBDLoLaRN5k6dzJvrX8BOXeDjMLQXA3ybdstuq5y6Y6MSCOm3lN/7s= X-Received: by 2002:adf:f9c8:: with SMTP id w8mr60764235wrr.354.1594280214366; Thu, 09 Jul 2020 00:36:54 -0700 (PDT) MIME-Version: 1.0 References: <20200707201229.472834-1-daniel.vetter@ffwll.ch> <20200707201229.472834-4-daniel.vetter@ffwll.ch> In-Reply-To: <20200707201229.472834-4-daniel.vetter@ffwll.ch> From: Daniel Stone Date: Thu, 9 Jul 2020 08:36:43 +0100 Message-ID: Subject: Re: [Intel-gfx] [PATCH 03/25] dma-buf.rst: Document why idenfinite fences are a bad idea To: Daniel Vetter Cc: DRI Development , =?UTF-8?Q?Christian_K=C3=B6nig?= , linux-rdma@vger.kernel.org, Intel Graphics Development , amd-gfx mailing list , Chris Wilson , "moderated list:DMA BUFFER SHARING FRAMEWORK" , Steve Pronovost , Jesse Natalie , Daniel Vetter , Thomas Hellstrom , "open list:DMA BUFFER SHARING FRAMEWORK" , Felix Kuehling , Mika Kuoppala Content-Type: text/plain; charset="UTF-8" Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Hi, On Tue, 7 Jul 2020 at 21:13, Daniel Vetter wrote: > Comes up every few years, gets somewhat tedious to discuss, let's > write this down once and for all. Thanks for writing this up! I wonder if any of the notes from my reply to the previous-version thread would be helpful to more explicitly encode the carrot of dma-fence's positive guarantees, rather than just the stick of 'don't do this'. ;) Either way, this is: Acked-by: Daniel Stone > What I'm not sure about is whether the text should be more explicit in > flat out mandating the amdkfd eviction fences for long running compute > workloads or workloads where userspace fencing is allowed. ... or whether we just say that you can never use dma-fence in conjunction with userptr. Cheers, Daniel