From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from wolverine01.qualcomm.com ([199.106.114.254]:44212 "EHLO wolverine01.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754516Ab2BLOTK (ORCPT ); Sun, 12 Feb 2012 09:19:10 -0500 Received: from HKADMANY (pdmz-snip-v218.qualcomm.com [192.168.218.1]) by mostmsg01.qualcomm.com (Postfix) with ESMTPA id 7875C10004D1 for ; Sun, 12 Feb 2012 06:19:09 -0800 (PST) From: "Hamad Kadmany" To: Subject: [media][dvb-core] Question on dvr device copy Date: Sun, 12 Feb 2012 16:19:24 +0200 Message-ID: <000001cce991$53bf56c0$fb3e0440$@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Language: en-us Sender: linux-media-owner@vger.kernel.org List-ID: Hi, Currently when playing stream from memory through dvr device (through write calls), the written buffer is copied from user-space to kernel space. The same applies when recording a stream, the TS packets received from HW are copied to dvr ring-buffer. I'm a bit concerned about the performance due to the copy, and whether we better have a memory mapped ring-buffer in dvr device output and/or dvr device input with user-space to cope with high bitrate streams. Your feedback on this will be mostly appreciated. Thanks Hamad