From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?utf-8?b?R3Vhbiw=?= Xin Subject: Re: [PATCH 0/2] Squashfs: add LZ4 compression Date: Fri, 5 Sep 2014 10:01:23 +0000 (UTC) Message-ID: References: <1374459663-15363-1-git-send-email-phillip@squashfs.org.uk> <51ECA17A.3060401@cn.fujitsu.com> <51ECCB8B.7030104@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: linux-fsdevel@vger.kernel.org Return-path: Received: from plane.gmane.org ([80.91.229.3]:50974 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755840AbaIEKFL (ORCPT ); Fri, 5 Sep 2014 06:05:11 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1XPqO7-0003rp-UB for linux-fsdevel@vger.kernel.org; Fri, 05 Sep 2014 12:05:06 +0200 Received: from 5mao.bbsindex.com ([74.121.150.153]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 05 Sep 2014 12:05:03 +0200 Received: from guanx.bac by 5mao.bbsindex.com with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 05 Sep 2014 12:05:03 +0200 Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Gu Zheng cn.fujitsu.com> writes: > But it's hard to say that it also really can bring benefit to Squashfs. I did observe faster I/O in my daily use. The start up time of applications on my squashfs+aufs root filesystem generally decreased by 10% to 20% compared to lzo. Not very much, but the absence of lag with lz4 greatly improved user experience. > Yes, but the premise is that using LZ4 in Squashfs is better than lzo > in at least one actual situation. I update my squashfs image (about 8GB compressed) ~ once every month. Lz4 yields slightly worse compression ratio (+20%) than lzo but its compression speed is about fifty (no typo) times faster. In order to get rid of the endless waiting on "mksquashfs -comp lzo", I had to port Phillip's patch (in particular the "lz4_wrapper.c") to Linux 3.14.x so I can use lz4 compressed squashfs images everyday. > Let's look and see other guys' feedbacks, they are more persuasive.:) IMHO, a 50x boost of compression speed is persuasive. Lz4 also helped me to get rid of occasional lags on file I/O, greatly improved user experience with my Linux desktop. Adding lz4 support to squashfs isn't complicated. Everyone can review the patch in a couple of minutes. So I vote on its inclusion in mainline. Guan