From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Vath Subject: Re: [PATCH 0/2] Squashfs: add LZ4 compression Date: Thu, 27 Nov 2014 17:55:40 +0100 (CET) Message-ID: References: <1417075250-6502-1-git-send-email-phillip@squashfs.org.uk> <20141127133754.GA12750@wolff.to> Mime-Version: 1.0 Content-Type: MULTIPART/MIXED; BOUNDARY="8323329-1311509108-1417106034=:17270" Cc: Bruno Wolff III , Phillip Lougher , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, texstar@gmail.com, Martin Vaeth , guanx.bac@gmail.com, dave@vasilevsky.ca, blyons@students.naropa.edu, tokiclover@gmail.com, afm404@gmail.com, hugochevrain@gmail.com To: Marcin Szychowski Return-path: In-Reply-To: Content-ID: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323329-1311509108-1417106034=:17270 Content-Type: TEXT/PLAIN; CHARSET=ISO-8859-15; FORMAT=flowed Content-Transfer-Encoding: 8BIT Content-ID: Hi: > squashfs+lz4 / aufs to speed up my laptop Squashfs proves its usefulness especially in combination with aufs or overlayfs; I suppose that this combination will become more popular with the spreading of overlayfs (e.g. to save disk space etc.) For users with such a combination, it is especially important to get a fast (re)compression of huge directories. The speed of LZ4 for compression in such a setting is really incredible. Just for orientation for myself, I made a list of times/sizes on some machines I had access to: https://github.com/vaeth/squashmount/blob/master/compress.txt (I do not claim that this is a scientific benchmark - just a straightforward average over several runs). The results for the kernel source and libreoffice are really unbelievable, but I repeated them several times (and, as you can see, for the kernel sources on different machines). >>From the user perspective, it is mainly important that the files compressed in this way can be read by the kernel - the decompression speed is here secondary, so I made no comparison for this case, although lz4 is known to be very fast also for decompression. I would really like to see lz4 support included in the squashfs kernel driver. I cannot imagine any negative consequences, especially since squashfs and lz4 are in the kernel, anyway. Sincerely Martin Väth --8323329-1311509108-1417106034=:17270--