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=-0.5 required=3.0 tests=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 8EB32C433E1 for ; Thu, 18 Jun 2020 07:18:23 +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 5F65721548 for ; Thu, 18 Jun 2020 07:18:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b="X4atcg3Q" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5F65721548 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ziepe.ca 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 CB8626EB09; Thu, 18 Jun 2020 07:17:35 +0000 (UTC) Received: from mail-qv1-xf41.google.com (mail-qv1-xf41.google.com [IPv6:2607:f8b0:4864:20::f41]) by gabe.freedesktop.org (Postfix) with ESMTPS id CF8C06E95A for ; Wed, 17 Jun 2020 15:29:42 +0000 (UTC) Received: by mail-qv1-xf41.google.com with SMTP id y9so1211418qvs.4 for ; Wed, 17 Jun 2020 08:29:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=v5BdIMSU0SgDrZuQSRW4xvIrY4rZ7WnbUK5J5TOXFb0=; b=X4atcg3QCitKJdCOr5ja2tE2bUBLSFF91J0CzDtXnsV5WejCzsk2eajJzTjXjsFLTA 5s+gkYE18Kz4f7uWFKMYMARjm17DhKgqFhDle7hMjPDQJSHTF3vHPDJzf/g8gfXm1XCc xS0VLL2kkFYRGpHsv6IKsvfpDgxixqoGb1C7eZAdpsByKmZrD/PLYevp7FEa9NQdLxHk yZFftabPuFhyEj1G7fMasvfilN4m93P/kXM+Vvvx/r/xyhIpvBM0x0Ha3wX71m2O7A/a L0H0SGP2pZKrl4si0m+rtOCOCb+j5CVmE5xryjAmjELn7Uqp0ivvBvKuiMRBNAyyx2kG itRw== 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:in-reply-to; bh=v5BdIMSU0SgDrZuQSRW4xvIrY4rZ7WnbUK5J5TOXFb0=; b=aZqhyftdM4s/sHkYHE8pq8CcWVe9TIu6tshoW3z6InAGX+n9oPQ3CI+Uliet3vCs1H cAVsWYXi5uYSxoUWwkIkjMurFfS+ImAB63tgXD6clkpilEBxlko77cwNgKNDLEQw1Em3 XE4y+5Pus7fgjQ6uPx/3zIUgiViJnp0q+UcabcroEzwgwv4zDj/7OISAgsvp7AndY+h8 3v03U+LP/WToFdk90mwOXdaxz3RtPnrMp7e9TScd5OG8hhKyzsUCGOey5DetFkcT2x67 ICdJpPXwn3SEc7lKBqIntgyFdCpA3euZG/1cxOzmsztUYhTs0Al8hNcT5M4QW6yKT60t J6oA== X-Gm-Message-State: AOAM530JC1rmE918+ycSpc7lXjAwoof0L5f0oiBIulKtzK2abZDX02RX 6LTXeiS33rXzUbXAvYvSvG+jVQ== X-Google-Smtp-Source: ABdhPJyWaY8mWagCAPiiX7EhWCqcjbxUamRd5/mDpg63tRR7xxsYdOaA9ycSUwn3S5FVu3UfHzBj0g== X-Received: by 2002:a0c:f388:: with SMTP id i8mr8163963qvk.224.1592407781973; Wed, 17 Jun 2020 08:29:41 -0700 (PDT) Received: from ziepe.ca (hlfxns017vw-156-34-48-30.dhcp-dynamic.fibreop.ns.bellaliant.net. [156.34.48.30]) by smtp.gmail.com with ESMTPSA id y13sm204954qto.23.2020.06.17.08.29.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Jun 2020 08:29:41 -0700 (PDT) Received: from jgg by mlx with local (Exim 4.93) (envelope-from ) id 1jla0S-009d9h-Uc; Wed, 17 Jun 2020 12:29:40 -0300 Date: Wed, 17 Jun 2020 12:29:40 -0300 From: Jason Gunthorpe To: Daniel Vetter Subject: Re: [Linaro-mm-sig] [PATCH 04/18] dma-fence: prime lockdep annotations Message-ID: <20200617152940.GG6578@ziepe.ca> References: <20200604081224.863494-1-daniel.vetter@ffwll.ch> <20200604081224.863494-5-daniel.vetter@ffwll.ch> <20200611083430.GD20149@phenom.ffwll.local> <20200611141515.GW6578@ziepe.ca> <20200616120719.GL20149@phenom.ffwll.local> <20200616145312.GC6578@ziepe.ca> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Mailman-Approved-At: Thu, 18 Jun 2020 07:17:31 +0000 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: linux-rdma , Thomas =?utf-8?B?SGVsbHN0csO2bSAoSW50ZWwp?= , LKML , DRI Development , Christian =?utf-8?B?S8O2bmln?= , "moderated list:DMA BUFFER SHARING FRAMEWORK" , Thomas Hellstrom , amd-gfx list , Daniel Vetter , Mika Kuoppala , Intel Graphics Development , "open list:DMA BUFFER SHARING FRAMEWORK" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Wed, Jun 17, 2020 at 09:57:54AM +0200, Daniel Vetter wrote: > > At the very least I think there should be some big warning that > > dma_fence in notifiers should be avoided. > > Yeah I'm working on documentation, and also the notifiers here > hopefully make it clear it's massive pain. I think we could even make > a hard rule that dma_fence in mmu notifier outside of drivers/gpu is a > bug/misfeature. Yep! > Might be a good idea to add a MAINTAINERS entry with a K: regex > pattern, so that you can catch such modifiers. We do already have such > a pattern for dma-fence, to catch abuse. So if you want I could type > up a documentation patch for this, get your and others acks and the > dri-devel folks would enforce that the dma_fence_wait madness doesn't > leak beyond drivers/gpu It seems like the best thing > Oded has agreed to remove the dma-fence usage, since they really don't > need it (and all the baggage that comes with it), plain old completion > is enough for their use. This use is also why I added the regex to > MAINTAINERS, so that in the future we can catch people who try to use > dma_fence because it looks cute and useful, and are completely > oblivious to all the pain and headaches involved. This is good! Thanks, Jason _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel