From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net ([212.227.17.21]:64341 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753067Ab3A2Lnh (ORCPT ); Tue, 29 Jan 2013 06:43:37 -0500 Received: from mailout-de.gmx.net ([10.1.76.30]) by mrigmx.server.lan (mrigmx001) with ESMTP (Nemesis) id 0Lg2yr-1UnkIG3i0Z-00pdJi for ; Tue, 29 Jan 2013 12:43:35 +0100 From: Egon Alter Subject: Re: [RFC PATCH 0/4] Add support for LZ4-compressed kernels Date: Tue, 29 Jan 2013 12:43:20 +0100 Message-ID: <34874167.ghObrToI03@fb07-iapwap2> In-Reply-To: <20130129101549.GP23505@n2100.arm.linux.org.uk> References: <1359179447-31118-1-git-send-email-kyungsik.lee@lge.com> <20130128142510.68092e10.akpm@linux-foundation.org> <20130129101549.GP23505@n2100.arm.linux.org.uk> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: linux-arm-kernel@lists.infradead.org Cc: Russell King - ARM Linux , Andrew Morton , Michal Marek , hyojun.im@lge.com, raphael.andy.lee@gmail.com, linux-kbuild@vger.kernel.org, gunho.lee@lge.com, namhyung.kim@lge.com, x86@kernel.org, linux-kernel@vger.kernel.org, Josh Triplett , Nitin Gupta , Richard Purdie , Ingo Molnar , Joe Millenbach , chan.jeong@lge.com, Kyungsik Lee , "H. Peter Anvin" , Thomas Gleixner , Albin Tonnerre , CE Linux Developers List , minchan.kim@lge.com Am Dienstag, 29. Januar 2013, 10:15:49 schrieb Russell King - ARM Linux: > On Mon, Jan 28, 2013 at 02:25:10PM -0800, Andrew Morton wrote: > > What's this "with enabled unaligned memory access" thing? You mean "if > > the arch supports CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS"? If so, > > that's only x86, which isn't really in the target market for this > > patch, yes? > > > > It's a lot of code for a 50ms boot-time improvement. Does anyone have > > any opinions on whether or not the benefits are worth the cost? > > Well... when I saw this my immediate reaction was "oh no, yet another > decompressor for the kernel". We have five of these things already. > Do we really need a sixth? > > My feeling is that we should have: > - one decompressor which is the fastest > - one decompressor for the highest compression ratio > - one popular decompressor (eg conventional gzip) the problem gets more complicated as the "fastest" decompressor usually creates larger images which need more time to load from the storage, e.g. a one MB larger image on a 10 MB/s storage (note: bootloaders often configure the storage controllers in slow modes) gives 100 ms more boot time, thus eating the gain of a "fast decompressor". Egon