From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753108AbbLEIH3 (ORCPT ); Sat, 5 Dec 2015 03:07:29 -0500 Received: from mga01.intel.com ([192.55.52.88]:32849 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752834AbbLEIH2 (ORCPT ); Sat, 5 Dec 2015 03:07:28 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,384,1444719600"; d="scan'208";a="834793649" Date: Sat, 5 Dec 2015 13:40:31 +0530 From: Vinod Koul To: Sinan Kaya Cc: dmaengine@vger.kernel.org, linux-arm-kernel@lists.infradead.org, "linux-kernel@vger.kernel.org" Subject: Re: [RFC] User space to kernel space copy optimization Message-ID: <20151205081030.GM1854@localhost> References: <564A5057.9080203@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <564A5057.9080203@codeaurora.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 16, 2015 at 04:53:27PM -0500, 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. > > 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. Do you have a proposal on how this generic solution should look like, broad contours of the design to start off with and we can start from that point -- ~Vinod