From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [PATCH 00/14] Pramfs: Persistent and protected ram filesystem Date: Sun, 28 Jun 2009 10:59:32 +0200 Message-ID: <20090628085932.GA20169@elf.ucw.cz> References: <4a4254e2.09c5660a.109d.46f8@mx.google.com> <4A425907.2060105@gmail.com> <4A42649D.6080509@gmail.com> <20090624175943.GB6618@elf.ucw.cz> <2ea1731b0906242330t5f379322sdff9880788e9b181@mail.gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <2ea1731b0906242330t5f379322sdff9880788e9b181@mail.gmail.com> Sender: linux-embedded-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="iso-8859-1" To: Marco Stornelli Cc: tim.bird@am.sony.com, jamie@shareable.org, Linux Embedded , Linux Kernel , Linux FS Devel , Daniel Walker > >> > Ah now the write protection is a "needed feature", in your previ= ous > >> > comment you talked about why not use ext2/3....... > >> > > >> > Marco > >> > > >> > >> Just for your information I tried the same test with pc in a virtu= al machine with 32MB of RAM: > >> > >> Version 1.03e =A0 =A0 =A0 ------Sequential Output------ --Sequenti= al Input- --Random- > >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 -Per Chr- --Block-- -Rewri= te- -Per Chr- --Block-- --Seeks-- > >> Machine =A0 Size:chnk K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/se= c %CP =A0/sec %CP > >> hostname =A0 =A0 15M:1k 14156 =A099 128779 100 92240 100 11669 100= 166242 =A099 80058 =A082 > >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 ------Sequential Create---= --- --------Random Create-------- > >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 -Create-- --Read--- -Delet= e-- -Create-- --Read--- -Delete-- > >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 files =A0/sec %CP =A0/sec %CP =A0/sec = %CP =A0/sec %CP =A0/sec %CP =A0/sec %CP > >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 4 =A02842 =A099 133506 104 450= 88 101 =A02787 =A099 79581 101 58212 102 > >> > >> These data are the proof of the importance of the environment, wor= kload and so on when we talk > >> about benchmark. Your consideration are really superficial. > > > > Unfortunately, your numbers are meaningless. >=20 > I don't think so. >=20 > > (PCs should have cca 3GB/sec RAM transfer rates; and you demosstrat= ed > > cca 166MB/sec read rate; disk is 80MB/sec, so that's too slow. If y= ou > > want to prove your filesystem the filesystem is reasonably fast, > > compare it with ext2 on ramdisk.) > > > This is the point. I don't want compare it with ext2 from performance > point of view. This comparison makes no sense for me. I've done this > test to prove that if you change environment you can change in a > purposeful way the results. Yes, IOW you demonstrated that the numbers are machine-dependend and really meaningless. ext2 comparison would tell you how much pramfs sucks (or not). Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses= /blog.html