From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from wolverine01.qualcomm.com ([199.106.114.254]:25751 "EHLO wolverine01.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753189Ab2BNHdg (ORCPT ); Tue, 14 Feb 2012 02:33:36 -0500 Received: from HKADMANY (pdmz-snip-v218.qualcomm.com [192.168.218.1]) by mostmsg01.qualcomm.com (Postfix) with ESMTPA id 5CAB810004D8 for ; Mon, 13 Feb 2012 23:33:35 -0800 (PST) From: "Hamad Kadmany" To: References: <000001cce991$53bf56c0$fb3e0440$@codeaurora.org> In-Reply-To: <000001cce991$53bf56c0$fb3e0440$@codeaurora.org> Subject: RE: [media][dvb-core] Question on dvr device copy Date: Tue, 14 Feb 2012 09:33:50 +0200 Message-ID: <000001cceaeb$00985860$01c90920$@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, I would appreciate if anyone can feedback on this, I'm considering implementing mmap in demux/dvr devices so that user-space can access the input/output buffers directly without the need for read/write operations. Thanks Hamad -----Original Message----- From: linux-media-owner@vger.kernel.org [mailto:linux-media-owner@vger.kernel.org] On Behalf Of Hamad Kadmany Sent: Sunday, February 12, 2012 4:19 PM To: linux-media@vger.kernel.org Subject: [media][dvb-core] Question on dvr device copy 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 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html