From owner-svn-src-all@FreeBSD.ORG Mon May 13 01:05:13 2013 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id CD30A38D; Mon, 13 May 2013 01:05:13 +0000 (UTC) (envelope-from kozlov@ravenloft.kiev.ua) Received: from ravenloft.kiev.ua (ravenloft.kiev.ua [94.244.131.95]) by mx1.freebsd.org (Postfix) with ESMTP id 8DF39991; Mon, 13 May 2013 01:05:13 +0000 (UTC) Date: Mon, 13 May 2013 04:05:12 +0300 From: Alex Kozlov To: Dmitry Morozovsky Subject: Re: svn commit: r250565 - head/etc Message-ID: <20130513010512.GA38811@ravenloft.kiev.ua> References: <201305121523.r4CFNxBR055568@svn.freebsd.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 13 May 2013 01:05:13 -0000 On Mon, May 13, 2013 at 01:41:28AM +0400, Dmitry Morozovsky wrote: > On Sun, 12 May 2013, Ed Schouten wrote: > > 2013/5/12 Dmitry Morozovsky : > > > I'm afraid it could produce more harm than goodness on old hardware > > > and/or other architectures like arm. > > Any change we make at FreeBSD may or may not cause problems on old > > hardware and/or other architectures like ARM. It's typically a case of > > trial and error to see what happens. > > In fact, I think that for embedded systems, using xz compression would > > even be better. Many of those systems are often more storage space > > constrained than CPU constrained (e.g. a 200 MHz wireless device with > > only 8 MB of flash). > > I think it's a pity the change has been reverted without bringing any > > hard data to the table. I've tested this change on i386/amd64 (Pentium T4400, the slowest I have), arm (Raspberry Pi) and very old mips (mips 24k). The difference in size between bzip2 and xz compressed logs around 20%. The difference in compression speed around 100%. But I believe that it is acceptable trade-of because logs rotation is an infrequent event, default log size make the absolute value of compression time negligible and xz decompresses several times faster than bzip2. Brief test results (compression, 1 thread): cpu xz T4400 1Mb/s rpi 0.8Mb/s mips 24k 0.07Mb/s (bzip2 0.16Mb/s) > I would pretty much like more statistics about the issue as well; > unfortunately, all I have handy are x86 hardware, and most of embedded-like > systems aer amd64 atoms... > > I think some testing should be done on different platforms before making any > kind of decisions. Oh well, let's just wait another 5 years. -- Alex