From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mailout1.w1.samsung.com ([210.118.77.11]:57871 "EHLO mailout1.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753688Ab1HBOsw (ORCPT ); Tue, 2 Aug 2011 10:48:52 -0400 Received: from eu_spt1 (mailout1.w1.samsung.com [210.118.77.11]) by mailout1.w1.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTP id <0LPB0027R2HEAW@mailout1.w1.samsung.com> for linux-media@vger.kernel.org; Tue, 02 Aug 2011 15:48:50 +0100 (BST) Received: from [127.0.0.1] ([106.10.22.58]) by spt1.w1.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTPA id <0LPB00HSU2HBGU@spt1.w1.samsung.com> for linux-media@vger.kernel.org; Tue, 02 Aug 2011 15:48:50 +0100 (BST) Date: Tue, 02 Aug 2011 16:48:48 +0200 From: Marek Szyprowski Subject: Re: [Linaro-mm-sig] Buffer sharing proof-of-concept In-reply-to: To: KyongHo Cho Cc: linaro-mm-sig@lists.linaro.org, linux-media@vger.kernel.org, Tomasz Stanislawski , Kyungmin Park Message-id: <4E380E50.8030302@samsung.com> MIME-version: 1.0 Content-type: text/plain; charset=ISO-8859-1; format=flowed Content-transfer-encoding: 7BIT References: <4E37C7D7.40301@samsung.com> Sender: linux-media-owner@vger.kernel.org List-ID: Hello, On 2011-08-02 13:59, KyongHo Cho wrote: > On Tue, Aug 2, 2011 at 6:48 PM, Marek Szyprowski > wrote: >> Hello Everyone, >> >> This patchset introduces the proof-of-concept infrastructure for buffer >> sharing between multiple devices using file descriptors. The infrastructure >> has been integrated with V4L2 framework, more specifically videobuf2 and two >> S5P drivers FIMC (capture interface) and TV drivers, but it can be easily >> used by other kernel subsystems, like DRI. >> >> In this patch the buffer object has been simplified to absolute minimum - it >> contains only the buffer physical address (only physically contiguous >> buffers are supported), but this can be easily extended to complete scatter >> list in the future. >> > > Is this patch set an attempt to share a buffer between different > processes via open file descriptors? > Your patches seems to include several constructs to pack information > about a buffer in an open file descriptor > and to unpack it. > > I don't have any idea what is the purpose of your attempts. > Is it the first step to the unified memory model that is being > discussed in Linaro? Yes, these patches were posted to demonstrate how sharing the buffers between different devices (currently only v4l2 based) can be implemented. We are discussing the idea of sharing the buffers on Memory Management summit on Linaro Sprint in Cambourne. Best regards -- Marek Szyprowski Samsung Poland R&D Center