From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [PATCH 3/5] Add support for LZO-compressed kernels Date: Wed, 22 Jul 2009 09:08:31 -0700 Message-ID: <4A67397F.8080705@zytor.com> References: <0022152d7fe9b6dbcf046f4d04a6@google.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <0022152d7fe9b6dbcf046f4d04a6@google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: kevin.granade@gmail.com Cc: Albin Tonnerre , linux@arm.linux.org.uk, alain@knaff.lu, linux-kernel@vger.kernel.org, linux-embedded@vger.kernel.org kevin.granade@gmail.com wrote: > > > > So for a compression ratio that is still relatively close to gzip, it's > > much faster to extract, at least in that case. > > Is that "time to run the extraction algorithm", or "time to read in > image from media and extract"? I think the time to read from the media > would tend to dominate the decompression time. > Either way, could you provide the other time for each algorithm in order > to give a sense of how this might scale to other CPU speeds/media read > speeds? > If you have very slow media, you probably want to use LZMA. If you have a very slow CPU and comparatively fast media, LZO might be a good option... I have heard people asking for *uncompressed* kernels for this reason, but LZO runs at a significant fraction of memcpy() speed. -hpa