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[124.171.87.207]) by smtp.gmail.com with ESMTPSA id u44sm9699150pgn.81.2020.04.13.23.21.30 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 13 Apr 2020 23:21:33 -0700 (PDT) Subject: Re: [PATCH 1/2] dma-mapping: add a dma_ops_bypass flag to struct device From: Alexey Kardashevskiy To: Christoph Hellwig Cc: "Aneesh Kumar K.V" , iommu@lists.linux-foundation.org, linuxppc-dev@lists.ozlabs.org, Lu Baolu , Greg Kroah-Hartman , Joerg Roedel , Robin Murphy , linux-kernel@vger.kernel.org, Michael Ellerman References: <87sghz2ibh.fsf@linux.ibm.com> <20200323172256.GB31269@lst.de> <20200324075402.GJ23447@lst.de> <41975da3-3a4a-fc3c-2b90-8d607cf220e6@ozlabs.ru> <20200325083740.GC21605@lst.de> <213b0c7d-f908-b4f4-466d-6240c3622cd6@ozlabs.ru> <20200406115016.GA10941@lst.de> <348046e7-7a38-62d6-4df0-e4a537b98926@ozlabs.ru> <20200406171706.GA3231@lst.de> <95395244-bdec-84d2-b81b-3040c076fe4d@ozlabs.ru> Autocrypt: addr=aik@ozlabs.ru; keydata= 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Kardashevskiy wrote: > > > On 07/04/2020 03:17, Christoph Hellwig wrote: >> On Mon, Apr 06, 2020 at 11:25:09PM +1000, Alexey Kardashevskiy wrote: >>>>> Do you see any serious problem with this approach? Thanks! >>>> >>>> Do you have a link to the whole branch? The github UI is unfortunately >>>> unusable for that (or I'm missing something). >>> >>> The UI shows the branch but since I rebased and forcepushed it, it does >>> not. Here is the current one with: >>> >>> https://github.com/aik/linux/commits/dma-bypass.3 >> >> Ok, so we use the core bypass without persistent memory, and then >> have another bypass mode on top. Not great, but I can't think >> of anything better. Note that your checks for the map_sg case >> aren't very efficient - for one it would make sense to calculate >> the limit only once, > > Good points, I'll post revised version when you post your v3 of this. Any plans on posting v3 of this? Thanks, > >> but also it would make sense to reuse the >> calculted diecect mapping addresses instead of doing another pass >> later on in the dma-direct code. > > Probably but I wonder what kind of hardware we need to see the > difference. I might try, just need to ride to the office to plug the > cable in my 100GBit eth machines :) Thanks, > > -- Alexey 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=-7.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 3943CC2BB1D for ; Tue, 14 Apr 2020 06:24:26 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 D9F172072D for ; Tue, 14 Apr 2020 06:24:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=ozlabs-ru.20150623.gappssmtp.com header.i=@ozlabs-ru.20150623.gappssmtp.com header.b="jlXnhyu7" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D9F172072D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ozlabs.ru Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 491b6v3GndzDqTw for ; Tue, 14 Apr 2020 16:24:23 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=ozlabs.ru (client-ip=2607:f8b0:4864:20::541; helo=mail-pg1-x541.google.com; envelope-from=aik@ozlabs.ru; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ozlabs.ru Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=ozlabs-ru.20150623.gappssmtp.com header.i=@ozlabs-ru.20150623.gappssmtp.com header.a=rsa-sha256 header.s=20150623 header.b=jlXnhyu7; dkim-atps=neutral Received: from mail-pg1-x541.google.com (mail-pg1-x541.google.com [IPv6:2607:f8b0:4864:20::541]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 491b3l1WHYzDqTx for ; Tue, 14 Apr 2020 16:21:38 +1000 (AEST) Received: by mail-pg1-x541.google.com with SMTP id g6so5552887pgs.9 for ; Mon, 13 Apr 2020 23:21:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ozlabs-ru.20150623.gappssmtp.com; s=20150623; h=subject:from:to:cc:references:autocrypt:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=T2V6RFxG+St6MIwHonDlDqJYtf1QoZ6rfA/nQPhlGxM=; b=jlXnhyu78Pr3Mf9T3zCyZ59xDjsHm3mWl3rYbZSrzdBF1tTa1afLDAfFkEOx40odgC UOJ2mgADsZhbLZC/mbBFYPobHXNEwLUlvqLwFNNZkbic1x8aOSRRE+nXAXAhGqFbkKiE DX6GdjyxxLEAEOu0fQ/Zv/7nYNhsDQqyH53V7fWCQEL6BQSD6uScccI+8yiNWhYIAIk+ lT92xWmziQdvsYLgjUxqFcpcDak5rZHQ9lRwe9MHp/VzXC/Bv7buD/ZWELIV90ZXX6lZ lgQs5ntF0YygigTCZb/4nvzcQYOtHFq1imyoiCZMp5OiLSMQoTc8HWjbi5EWeSQN3fWL n71Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:references:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=T2V6RFxG+St6MIwHonDlDqJYtf1QoZ6rfA/nQPhlGxM=; b=GaPc0gMUOoa6NQrc5FS47TNpzh/gjQUCMBa9j0HRXqpTV/zYOzZOaakfujlS7p88xM eN+X9DJkSvc3rX+pYJXtAdnwAhDPf7wWImB1ktN5FXN3NlxMXcmc1oESslY4HRggt5Z2 wYVV0dwgGr2qLEwW04H/3mYtoUChu/nPP8ZF2qQIJqSt88z1ElyrzvGSvma/uLoaRKkt OtbqTct/oE58Qa90CBCiCTz29ReU6qbJTIkLsN8HJ+mLsP25FXaxOla13RDhCqEBO0e2 3WquyDq1vENRXyGWEINqkVwsz1owwSOqjG/wqSOxS6B4tyLv96z1qMPjYG3KsfrjStdW PJOQ== X-Gm-Message-State: AGi0Pubc5VcT0gdOuu+B7gCYSNbpj2L2akn0aoLEtFoLjFgQ0cJkbT7M Ec1BwrHY9QE/40v7bRKy5ubRZA== X-Google-Smtp-Source: APiQypL83TT0KlsOsKIJ3fvR06bQJNuFT6Oa4gTm65rKyfX1kCum+En95qF9urIy+WRzq1bLEYqidA== X-Received: by 2002:a63:7d5d:: with SMTP id m29mr15941343pgn.65.1586845294300; Mon, 13 Apr 2020 23:21:34 -0700 (PDT) Received: from [192.168.10.94] (124-171-87-207.dyn.iinet.net.au. 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linuxppc-dev@lists.ozlabs.org, Lu Baolu Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 07/04/2020 20:12, Alexey Kardashevskiy wrote: > > > On 07/04/2020 03:17, Christoph Hellwig wrote: >> On Mon, Apr 06, 2020 at 11:25:09PM +1000, Alexey Kardashevskiy wrote: >>>>> Do you see any serious problem with this approach? Thanks! >>>> >>>> Do you have a link to the whole branch? The github UI is unfortunately >>>> unusable for that (or I'm missing something). >>> >>> The UI shows the branch but since I rebased and forcepushed it, it does >>> not. Here is the current one with: >>> >>> https://github.com/aik/linux/commits/dma-bypass.3 >> >> Ok, so we use the core bypass without persistent memory, and then >> have another bypass mode on top. Not great, but I can't think >> of anything better. Note that your checks for the map_sg case >> aren't very efficient - for one it would make sense to calculate >> the limit only once, > > Good points, I'll post revised version when you post your v3 of this. Any plans on posting v3 of this? Thanks, > >> but also it would make sense to reuse the >> calculted diecect mapping addresses instead of doing another pass >> later on in the dma-direct code. > > Probably but I wonder what kind of hardware we need to see the > difference. I might try, just need to ride to the office to plug the > cable in my 100GBit eth machines :) Thanks, > > -- Alexey 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=-7.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 40B86C2BB1D for ; Tue, 14 Apr 2020 06:21:41 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (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 20209206E9 for ; Tue, 14 Apr 2020 06:21:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=ozlabs-ru.20150623.gappssmtp.com header.i=@ozlabs-ru.20150623.gappssmtp.com header.b="jlXnhyu7" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 20209206E9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ozlabs.ru Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id EA55B86439; Tue, 14 Apr 2020 06:21:39 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id oYDQfg6uX4tU; Tue, 14 Apr 2020 06:21:38 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by whitealder.osuosl.org (Postfix) with ESMTP id CC69D863F4; Tue, 14 Apr 2020 06:21:38 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id B4FAFC1D7D; Tue, 14 Apr 2020 06:21:38 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 6B9F4C0172 for ; Tue, 14 Apr 2020 06:21:36 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 59CB887B05 for ; Tue, 14 Apr 2020 06:21:36 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id LWGgFtVV7Z0g for ; Tue, 14 Apr 2020 06:21:35 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mail-pf1-f193.google.com (mail-pf1-f193.google.com [209.85.210.193]) by hemlock.osuosl.org (Postfix) with ESMTPS id 0B3CF87AFE for ; Tue, 14 Apr 2020 06:21:34 +0000 (UTC) Received: by mail-pf1-f193.google.com with SMTP id k15so5625508pfh.6 for ; Mon, 13 Apr 2020 23:21:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ozlabs-ru.20150623.gappssmtp.com; s=20150623; h=subject:from:to:cc:references:autocrypt:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=T2V6RFxG+St6MIwHonDlDqJYtf1QoZ6rfA/nQPhlGxM=; b=jlXnhyu78Pr3Mf9T3zCyZ59xDjsHm3mWl3rYbZSrzdBF1tTa1afLDAfFkEOx40odgC UOJ2mgADsZhbLZC/mbBFYPobHXNEwLUlvqLwFNNZkbic1x8aOSRRE+nXAXAhGqFbkKiE DX6GdjyxxLEAEOu0fQ/Zv/7nYNhsDQqyH53V7fWCQEL6BQSD6uScccI+8yiNWhYIAIk+ lT92xWmziQdvsYLgjUxqFcpcDak5rZHQ9lRwe9MHp/VzXC/Bv7buD/ZWELIV90ZXX6lZ lgQs5ntF0YygigTCZb/4nvzcQYOtHFq1imyoiCZMp5OiLSMQoTc8HWjbi5EWeSQN3fWL n71Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:references:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=T2V6RFxG+St6MIwHonDlDqJYtf1QoZ6rfA/nQPhlGxM=; b=Ixy1kiain1a9DkswLqVaWbCuorgpcZc9mFiQfGGpnwqD9N4Y5IxZTuiKsdlXn4hwTB NnQ4shziNZY/+qvSI3eNQXVaIOoryzDOwDTzK1baytjH4YM6GIlKefwjpZfm7Ns5zRDR xP/z1yhyqvbwF6gWdG6i/GtjBhC8if4JZEUAvjw8gQwaPNJ+mAytVrSywaT++KWWftaz RShvaaGWUFkDG5RsGdv2cd+bT4QDE/8Eo4kAlcrJ54OT23SGdedjuwejwGnzWkhoHVzO J59kwZUsWgRLa1YL4Xvce6ha1YGCgUzlCKoCgjrg+LWRJ5cZNuGZA8Fx6jT2X5fto5qz XjgA== X-Gm-Message-State: AGi0PubOc99hThA295zx/WidGGD493HJpMkNfdSxuU4xRHDELRF794L2 54hfVUjVqIyHEm/PJxSrf//w9w== X-Google-Smtp-Source: APiQypL83TT0KlsOsKIJ3fvR06bQJNuFT6Oa4gTm65rKyfX1kCum+En95qF9urIy+WRzq1bLEYqidA== X-Received: by 2002:a63:7d5d:: with SMTP id m29mr15941343pgn.65.1586845294300; Mon, 13 Apr 2020 23:21:34 -0700 (PDT) Received: from [192.168.10.94] (124-171-87-207.dyn.iinet.net.au. [124.171.87.207]) by smtp.gmail.com with ESMTPSA id u44sm9699150pgn.81.2020.04.13.23.21.30 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 13 Apr 2020 23:21:33 -0700 (PDT) Subject: Re: [PATCH 1/2] dma-mapping: add a dma_ops_bypass flag to struct device From: Alexey Kardashevskiy To: Christoph Hellwig References: <87sghz2ibh.fsf@linux.ibm.com> <20200323172256.GB31269@lst.de> <20200324075402.GJ23447@lst.de> <41975da3-3a4a-fc3c-2b90-8d607cf220e6@ozlabs.ru> <20200325083740.GC21605@lst.de> <213b0c7d-f908-b4f4-466d-6240c3622cd6@ozlabs.ru> <20200406115016.GA10941@lst.de> <348046e7-7a38-62d6-4df0-e4a537b98926@ozlabs.ru> <20200406171706.GA3231@lst.de> <95395244-bdec-84d2-b81b-3040c076fe4d@ozlabs.ru> Autocrypt: addr=aik@ozlabs.ru; keydata= mQINBE+rT0sBEADFEI2UtPRsLLvnRf+tI9nA8T91+jDK3NLkqV+2DKHkTGPP5qzDZpRSH6mD EePO1JqpVuIow/wGud9xaPA5uvuVgRS1q7RU8otD+7VLDFzPRiRE4Jfr2CW89Ox6BF+q5ZPV /pS4v4G9eOrw1v09lEKHB9WtiBVhhxKK1LnUjPEH3ifkOkgW7jFfoYgTdtB3XaXVgYnNPDFo 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Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On 07/04/2020 20:12, Alexey Kardashevskiy wrote: > > > On 07/04/2020 03:17, Christoph Hellwig wrote: >> On Mon, Apr 06, 2020 at 11:25:09PM +1000, Alexey Kardashevskiy wrote: >>>>> Do you see any serious problem with this approach? Thanks! >>>> >>>> Do you have a link to the whole branch? The github UI is unfortunately >>>> unusable for that (or I'm missing something). >>> >>> The UI shows the branch but since I rebased and forcepushed it, it does >>> not. Here is the current one with: >>> >>> https://github.com/aik/linux/commits/dma-bypass.3 >> >> Ok, so we use the core bypass without persistent memory, and then >> have another bypass mode on top. Not great, but I can't think >> of anything better. Note that your checks for the map_sg case >> aren't very efficient - for one it would make sense to calculate >> the limit only once, > > Good points, I'll post revised version when you post your v3 of this. Any plans on posting v3 of this? Thanks, > >> but also it would make sense to reuse the >> calculted diecect mapping addresses instead of doing another pass >> later on in the dma-direct code. > > Probably but I wonder what kind of hardware we need to see the > difference. I might try, just need to ride to the office to plug the > cable in my 100GBit eth machines :) Thanks, > > -- Alexey _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu