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=-4.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 11019C48BE5 for ; Tue, 22 Jun 2021 06:37:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EFC7F60FEA for ; Tue, 22 Jun 2021 06:37:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229695AbhFVGji (ORCPT ); Tue, 22 Jun 2021 02:39:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49566 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229574AbhFVGjh (ORCPT ); Tue, 22 Jun 2021 02:39:37 -0400 Received: from mail-ed1-x534.google.com (mail-ed1-x534.google.com [IPv6:2a00:1450:4864:20::534]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CD89BC061756; Mon, 21 Jun 2021 23:37:20 -0700 (PDT) Received: by mail-ed1-x534.google.com with SMTP id s6so22080123edu.10; Mon, 21 Jun 2021 23:37:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding:content-language; bh=ARIuYpj0vICVBtmBb3c3c4gAgJZM8iqcs3K8o/EZTjo=; b=iUMD7Hk4c0JkMp0x+Dln9bhYJl3rjQlccq+p6tXmffk7ioCjS8gyxJDmuE2F7hDSBG Q0jOeZOZhTzxMfBICEbNTh9/Hq32KI8q0jafUrAZCH9VDqxOdZz0dXaIFuqWf8JraUMB pi0Wp3RzfTBmK6ItILEqsfyOYMKzBA297ivkmXyjnj0CS/vsXqIHIXrlTmB1v2H6XbwN wOKF5bKVP+qVPcmezEpyZoFS/gYtwvIJqwfbPTI/O7tFB0pWdBN4wRsabWnEMOS1aLPZ c1zX7Y9N87rIPOQ08tAtdwRUrJ4Xm0aYh9w4Yz9mk8vxFfb+XAlj6yNpGBCFeU8xa65N a8Bg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=ARIuYpj0vICVBtmBb3c3c4gAgJZM8iqcs3K8o/EZTjo=; b=pmVL2CEKaULl3kDCOIvZs61ZwcLIbMmea22cT93FAfmtLjR0y3BRnsTihvePxesXXp WzwU4vnjAHaEFKzD04QD/4YnEc+GnAR7U8fahjoKeS4cz9KwXO1M2yzkP/8fvzyweqzM skf/700GGS2KN2dhJUItTAHHBMbbgBTjRKeFrSMXvBJsHrDzbugxTx/GbepupZOJzlmz ZmcrTlh9c02xcwTcd4fiR9hdUP5P7OycO2AJxhVmojCqnApkrMOP7sNh4NMfx2GGc2If KV5j6fRG4fFgdo0Z00IJrolWINGhkVyCP0ACX4qGAaaiIKcoPxzh0dbY2defDkYilkdS qCEQ== X-Gm-Message-State: AOAM530NKNcfDzbYbuR0yekFAEzNgN8Hik+fiTw/q/1+Fc19RFOtUAUc wHPcnUEkLvkx6AH48aFsjdBijxc5eTQ= X-Google-Smtp-Source: ABdhPJwiVGo3pmIkaPSyoKltDY97MiB1i1xd6tbT4Ywmxox6TqJUxOsJ5UQwUuiz7VochB1nnWV0Fg== X-Received: by 2002:aa7:d34f:: with SMTP id m15mr2693414edr.311.1624343837985; Mon, 21 Jun 2021 23:37:17 -0700 (PDT) Received: from ?IPv6:2a02:908:1252:fb60:9dfd:8ca7:7f8d:67e4? ([2a02:908:1252:fb60:9dfd:8ca7:7f8d:67e4]) by smtp.gmail.com with ESMTPSA id f14sm1006382edd.69.2021.06.21.23.37.16 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 21 Jun 2021 23:37:17 -0700 (PDT) Subject: Re: [Linaro-mm-sig] [PATCH v3 1/2] habanalabs: define uAPI to export FD for DMA-BUF To: Jason Gunthorpe , Oded Gabbay Cc: Gal Pressman , sleybo@amazon.com, linux-rdma , Oded Gabbay , Christoph Hellwig , Linux Kernel Mailing List , dri-devel , =?UTF-8?Q?Christian_K=c3=b6nig?= , "moderated list:DMA BUFFER SHARING FRAMEWORK" , Doug Ledford , Tomer Tayar , amd-gfx list , Greg KH , Alex Deucher , Leon Romanovsky , "open list:DMA BUFFER SHARING FRAMEWORK" References: <20210618123615.11456-1-ogabbay@kernel.org> <20210621141217.GE1096940@ziepe.ca> <20210621175511.GI1096940@ziepe.ca> <20210621232912.GK1096940@ziepe.ca> From: =?UTF-8?Q?Christian_K=c3=b6nig?= Message-ID: Date: Tue, 22 Jun 2021 08:37:15 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20210621232912.GK1096940@ziepe.ca> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Am 22.06.21 um 01:29 schrieb Jason Gunthorpe: > On Mon, Jun 21, 2021 at 10:24:16PM +0300, Oded Gabbay wrote: > >> Another thing I want to emphasize is that we are doing p2p only >> through the export/import of the FD. We do *not* allow the user to >> mmap the dma-buf as we do not support direct IO. So there is no access >> to these pages through the userspace. > Arguably mmaping the memory is a better choice, and is the direction > that Logan's series goes in. Here the use of DMABUF was specifically > designed to allow hitless revokation of the memory, which this isn't > even using. The major problem with this approach is that DMA-buf is also used for memory which isn't CPU accessible. That was one of the reasons we didn't even considered using the mapping memory approach for GPUs. Regards, Christian. > > So you are taking the hit of very limited hardware support and reduced > performance just to squeeze into DMABUF.. > > Jason > _______________________________________________ > Linaro-mm-sig mailing list > Linaro-mm-sig@lists.linaro.org > https://lists.linaro.org/mailman/listinfo/linaro-mm-sig 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=-2.0 required=3.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 0D31DC48BDF for ; Tue, 22 Jun 2021 06:37:23 +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 CF1D6611AF for ; Tue, 22 Jun 2021 06:37:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CF1D6611AF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com 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 3803D89E65; Tue, 22 Jun 2021 06:37:21 +0000 (UTC) Received: from mail-ed1-x536.google.com (mail-ed1-x536.google.com [IPv6:2a00:1450:4864:20::536]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5F3E689DF9; Tue, 22 Jun 2021 06:37:19 +0000 (UTC) Received: by mail-ed1-x536.google.com with SMTP id i5so4681072eds.1; Mon, 21 Jun 2021 23:37:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding:content-language; bh=ARIuYpj0vICVBtmBb3c3c4gAgJZM8iqcs3K8o/EZTjo=; b=iUMD7Hk4c0JkMp0x+Dln9bhYJl3rjQlccq+p6tXmffk7ioCjS8gyxJDmuE2F7hDSBG Q0jOeZOZhTzxMfBICEbNTh9/Hq32KI8q0jafUrAZCH9VDqxOdZz0dXaIFuqWf8JraUMB pi0Wp3RzfTBmK6ItILEqsfyOYMKzBA297ivkmXyjnj0CS/vsXqIHIXrlTmB1v2H6XbwN wOKF5bKVP+qVPcmezEpyZoFS/gYtwvIJqwfbPTI/O7tFB0pWdBN4wRsabWnEMOS1aLPZ c1zX7Y9N87rIPOQ08tAtdwRUrJ4Xm0aYh9w4Yz9mk8vxFfb+XAlj6yNpGBCFeU8xa65N a8Bg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=ARIuYpj0vICVBtmBb3c3c4gAgJZM8iqcs3K8o/EZTjo=; b=AwjLSCqc1IDf+4/IMK3wg1w1lpxXN8mv1AW+amOy4vwhhb038iesfrvh9glaSR7hwW 6LcSiUgntOd7xi0kf8yDxhW2L/dJoreeBiidrR13vdRNCjJ0iqu9zyPD4Vl4lwGtjctF yNeSjQH236BrswAIyXC5ifhskMUoYKUTB0kXez8Cy5y1cHO8A1YyFX5q7JYujOllksGH IayfBRvZcTN25Bk1nEkzv1IRUDUhUyJjq9nWmF9z/Txv4SZCKXDGGMIPlK2y6C7wuzwB RPBNG4BQklnnt1QFlX5dpw7pLH+NYuOFrfYu56aVxVXDewuYvDI1rnGbbHQX8DDX9Azv Hc9A== X-Gm-Message-State: AOAM531n1OGoIGQcrP1icrBnrFbYuPYMW3g8eZ+ef0bIa2/GQiQuIbXy VthzgUtm6FjmN88iIKeayRI= X-Google-Smtp-Source: ABdhPJwiVGo3pmIkaPSyoKltDY97MiB1i1xd6tbT4Ywmxox6TqJUxOsJ5UQwUuiz7VochB1nnWV0Fg== X-Received: by 2002:aa7:d34f:: with SMTP id m15mr2693414edr.311.1624343837985; Mon, 21 Jun 2021 23:37:17 -0700 (PDT) Received: from ?IPv6:2a02:908:1252:fb60:9dfd:8ca7:7f8d:67e4? ([2a02:908:1252:fb60:9dfd:8ca7:7f8d:67e4]) by smtp.gmail.com with ESMTPSA id f14sm1006382edd.69.2021.06.21.23.37.16 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 21 Jun 2021 23:37:17 -0700 (PDT) Subject: Re: [Linaro-mm-sig] [PATCH v3 1/2] habanalabs: define uAPI to export FD for DMA-BUF To: Jason Gunthorpe , Oded Gabbay References: <20210618123615.11456-1-ogabbay@kernel.org> <20210621141217.GE1096940@ziepe.ca> <20210621175511.GI1096940@ziepe.ca> <20210621232912.GK1096940@ziepe.ca> From: =?UTF-8?Q?Christian_K=c3=b6nig?= Message-ID: Date: Tue, 22 Jun 2021 08:37:15 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20210621232912.GK1096940@ziepe.ca> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US 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: =?UTF-8?Q?Christian_K=c3=b6nig?= , linux-rdma , Greg KH , Oded Gabbay , Gal Pressman , dri-devel , Linux Kernel Mailing List , "moderated list:DMA BUFFER SHARING FRAMEWORK" , Doug Ledford , Tomer Tayar , amd-gfx list , Alex Deucher , Christoph Hellwig , sleybo@amazon.com, Leon Romanovsky , "open list:DMA BUFFER SHARING FRAMEWORK" Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Am 22.06.21 um 01:29 schrieb Jason Gunthorpe: > On Mon, Jun 21, 2021 at 10:24:16PM +0300, Oded Gabbay wrote: > >> Another thing I want to emphasize is that we are doing p2p only >> through the export/import of the FD. We do *not* allow the user to >> mmap the dma-buf as we do not support direct IO. So there is no access >> to these pages through the userspace. > Arguably mmaping the memory is a better choice, and is the direction > that Logan's series goes in. Here the use of DMABUF was specifically > designed to allow hitless revokation of the memory, which this isn't > even using. The major problem with this approach is that DMA-buf is also used for memory which isn't CPU accessible. That was one of the reasons we didn't even considered using the mapping memory approach for GPUs. Regards, Christian. > > So you are taking the hit of very limited hardware support and reduced > performance just to squeeze into DMABUF.. > > Jason > _______________________________________________ > Linaro-mm-sig mailing list > Linaro-mm-sig@lists.linaro.org > https://lists.linaro.org/mailman/listinfo/linaro-mm-sig 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=-2.0 required=3.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 59AECC2B9F4 for ; Tue, 22 Jun 2021 06:37:21 +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 121B8611AF for ; Tue, 22 Jun 2021 06:37:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 121B8611AF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=amd-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B9CBE89DF9; Tue, 22 Jun 2021 06:37:20 +0000 (UTC) Received: from mail-ed1-x536.google.com (mail-ed1-x536.google.com [IPv6:2a00:1450:4864:20::536]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5F3E689DF9; Tue, 22 Jun 2021 06:37:19 +0000 (UTC) Received: by mail-ed1-x536.google.com with SMTP id i5so4681072eds.1; Mon, 21 Jun 2021 23:37:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding:content-language; bh=ARIuYpj0vICVBtmBb3c3c4gAgJZM8iqcs3K8o/EZTjo=; b=iUMD7Hk4c0JkMp0x+Dln9bhYJl3rjQlccq+p6tXmffk7ioCjS8gyxJDmuE2F7hDSBG Q0jOeZOZhTzxMfBICEbNTh9/Hq32KI8q0jafUrAZCH9VDqxOdZz0dXaIFuqWf8JraUMB pi0Wp3RzfTBmK6ItILEqsfyOYMKzBA297ivkmXyjnj0CS/vsXqIHIXrlTmB1v2H6XbwN wOKF5bKVP+qVPcmezEpyZoFS/gYtwvIJqwfbPTI/O7tFB0pWdBN4wRsabWnEMOS1aLPZ c1zX7Y9N87rIPOQ08tAtdwRUrJ4Xm0aYh9w4Yz9mk8vxFfb+XAlj6yNpGBCFeU8xa65N a8Bg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=ARIuYpj0vICVBtmBb3c3c4gAgJZM8iqcs3K8o/EZTjo=; b=AwjLSCqc1IDf+4/IMK3wg1w1lpxXN8mv1AW+amOy4vwhhb038iesfrvh9glaSR7hwW 6LcSiUgntOd7xi0kf8yDxhW2L/dJoreeBiidrR13vdRNCjJ0iqu9zyPD4Vl4lwGtjctF yNeSjQH236BrswAIyXC5ifhskMUoYKUTB0kXez8Cy5y1cHO8A1YyFX5q7JYujOllksGH IayfBRvZcTN25Bk1nEkzv1IRUDUhUyJjq9nWmF9z/Txv4SZCKXDGGMIPlK2y6C7wuzwB RPBNG4BQklnnt1QFlX5dpw7pLH+NYuOFrfYu56aVxVXDewuYvDI1rnGbbHQX8DDX9Azv Hc9A== X-Gm-Message-State: AOAM531n1OGoIGQcrP1icrBnrFbYuPYMW3g8eZ+ef0bIa2/GQiQuIbXy VthzgUtm6FjmN88iIKeayRI= X-Google-Smtp-Source: ABdhPJwiVGo3pmIkaPSyoKltDY97MiB1i1xd6tbT4Ywmxox6TqJUxOsJ5UQwUuiz7VochB1nnWV0Fg== X-Received: by 2002:aa7:d34f:: with SMTP id m15mr2693414edr.311.1624343837985; Mon, 21 Jun 2021 23:37:17 -0700 (PDT) Received: from ?IPv6:2a02:908:1252:fb60:9dfd:8ca7:7f8d:67e4? ([2a02:908:1252:fb60:9dfd:8ca7:7f8d:67e4]) by smtp.gmail.com with ESMTPSA id f14sm1006382edd.69.2021.06.21.23.37.16 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 21 Jun 2021 23:37:17 -0700 (PDT) Subject: Re: [Linaro-mm-sig] [PATCH v3 1/2] habanalabs: define uAPI to export FD for DMA-BUF To: Jason Gunthorpe , Oded Gabbay References: <20210618123615.11456-1-ogabbay@kernel.org> <20210621141217.GE1096940@ziepe.ca> <20210621175511.GI1096940@ziepe.ca> <20210621232912.GK1096940@ziepe.ca> From: =?UTF-8?Q?Christian_K=c3=b6nig?= Message-ID: Date: Tue, 22 Jun 2021 08:37:15 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20210621232912.GK1096940@ziepe.ca> Content-Language: en-US X-BeenThere: amd-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion list for AMD gfx List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: =?UTF-8?Q?Christian_K=c3=b6nig?= , linux-rdma , Greg KH , Oded Gabbay , Gal Pressman , dri-devel , Linux Kernel Mailing List , "moderated list:DMA BUFFER SHARING FRAMEWORK" , Doug Ledford , Tomer Tayar , amd-gfx list , Alex Deucher , Christoph Hellwig , sleybo@amazon.com, Leon Romanovsky , "open list:DMA BUFFER SHARING FRAMEWORK" Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: amd-gfx-bounces@lists.freedesktop.org Sender: "amd-gfx" Am 22.06.21 um 01:29 schrieb Jason Gunthorpe: > On Mon, Jun 21, 2021 at 10:24:16PM +0300, Oded Gabbay wrote: > >> Another thing I want to emphasize is that we are doing p2p only >> through the export/import of the FD. We do *not* allow the user to >> mmap the dma-buf as we do not support direct IO. So there is no access >> to these pages through the userspace. > Arguably mmaping the memory is a better choice, and is the direction > that Logan's series goes in. Here the use of DMABUF was specifically > designed to allow hitless revokation of the memory, which this isn't > even using. The major problem with this approach is that DMA-buf is also used for memory which isn't CPU accessible. That was one of the reasons we didn't even considered using the mapping memory approach for GPUs. Regards, Christian. > > So you are taking the hit of very limited hardware support and reduced > performance just to squeeze into DMABUF.. > > Jason > _______________________________________________ > Linaro-mm-sig mailing list > Linaro-mm-sig@lists.linaro.org > https://lists.linaro.org/mailman/listinfo/linaro-mm-sig _______________________________________________ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx