From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752848AbbKPW5v (ORCPT ); Mon, 16 Nov 2015 17:57:51 -0500 Received: from mga02.intel.com ([134.134.136.20]:32984 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752770AbbKPW5t (ORCPT ); Mon, 16 Nov 2015 17:57:49 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,304,1444719600"; d="scan'208";a="601414799" From: "Jiang, Dave" To: "dmaengine@vger.kernel.org" , "okaya@codeaurora.org" CC: "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [RFC] User space to kernel space copy optimization Thread-Topic: [RFC] User space to kernel space copy optimization Thread-Index: AQHRILlM5q8XM1YWAEuBWAGJNwLqn56fyRWA Date: Mon, 16 Nov 2015 22:57:47 +0000 Message-ID: <1447714667.83864.212.camel@intel.com> References: <564A5057.9080203@codeaurora.org> In-Reply-To: <564A5057.9080203@codeaurora.org> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [143.182.136.122] Content-Type: text/plain; charset="utf-8" Content-ID: <58A7B19A3FEA3049B90D5212C85319C9@intel.com> MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id tAGMvtD7005057 On Mon, 2015-11-16 at 21:53 +0000, Sinan Kaya wrote: > One of the things I'm interested in is to use a memcpy capable DMA > engine HW to optimize user space and kernel space parameter copying. Have you looked at why NET_DMA was deprecated and using DMA engine to do kernel->user copy could be a problem? https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/ ?id=77873803363c > > Of course, this will not be viable for all parameter sizes but I can > see > this being useful. The goal is to save power in the cost of little > performance. > > Before I go and invent my own mechanism, I'd like to have ideas on > what > an acceptable solution would look like. Especially, I'm looking for a > generic implementation that could plug into any DMA engine HW. > > -- > Sinan Kaya > Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, > Inc. > Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a > Linux Foundation Collaborative Project > -- > To unsubscribe from this list: send the line "unsubscribe dmaengine" > in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html{.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I