From mboxrd@z Thu Jan 1 00:00:00 1970 From: Petr Stehlik Subject: Re: nfhd performance Date: Mon, 19 Aug 2013 17:48:24 +0200 Message-ID: <1376927304.17125.19.camel@pracovni> References: <03094f45e85bca24df9306f73df2c84c@biophys.uni-duesseldorf.de> <21010.11209.818043.191186@pilspetsen.it.uu.se> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-2" Content-Transfer-Encoding: 7bit Return-path: Received: from mx.zln.cz ([188.246.101.4]:53722 "EHLO mx.zln.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751062Ab3HSPsf (ORCPT ); Mon, 19 Aug 2013 11:48:35 -0400 In-Reply-To: <21010.11209.818043.191186@pilspetsen.it.uu.se> Sender: linux-m68k-owner@vger.kernel.org List-Id: linux-m68k@vger.kernel.org To: Mikael Pettersson Cc: Geert Uytterhoeven , Michael Schmitz , Linux/m68k , aranym@lists.bobek.cz > Part of the problem is that ByteSwap = No setting. Contrary to what one might > think, "No" there actually means "yes, byteswap every sector read or written". > > Grep for byteswap in aranym's src/natfeat/xhdi.cpp if you don't believe me... > > As far as I can tell, this setting is only meaningful if you have an image which > must be shared with actual HW, and you don't want to byteswap it when migrating > it between these two roles (HW or aranym). I don't have that requirement, so I > run my aranym VMs with ByteSwap = Yes, which eliminates that overhead. Very true. > There are also other things in xhdi.cpp I don't really like, such as going through > stdio when raw Unix file-descriptors would do, and the small I/O unit size. Please suggest a better yet portable way. I've been thinking about reading more than a single sector at once, that could help a bit. Should write a benchmark for it first, it seems. Petr