On Sun, Dec 05, 2004 at 11:40:21AM +0100, Michael M?ller wrote: > Hi all, > > I read an article in the German 'Linux Magazin' 11/04 about a > comparision of the different FS. They tested Ext2, Ext3, JFS, XFS, > ReiserFS, Reiser4 and Veritas. Detailed results can be found on > http://www.linux-magazin.de/Service/Listings/2004/11/fs_bench. > > My question is: Why is the reading performance of every FS (available > for both Linux versions) under 2.6 so bad compared to 2.4? 2.6 looses > nearly 50%! > > The write performance is depending on the file size sometimes slightly > higher or lower. > > Can you tell me in short words what changed from 2.4 to 2.6 that > explains the difference? > > I thought that every major kernel release makes things better. So what > is now so much better that is worth to loose 50% performance? >
Well, it's fairly clear they messed something up here. My guess is that they didn't set the readahead high enough for whatever type of device they were testing on 2.6 (It looks like a Raid array, since on 2.4 it gets about 100MB/sec, which I don't think very many single disks can do). The readahead implementation on 2.6 is certainly different from the one on 2.4. IO performance on 2.6 is much, much better across the board. My German isn't great, so I'm not going to try and read the article, but I'd also like to know what kind of array they are using for this test. Before we can make any conclusions, we should know what the hardware is capable of doing. Sonny _______________________________________________ Jfs-discussion mailing list [EMAIL PROTECTED] http://www-124.ibm.com/developerworks/oss/mailman/listinfo/jfs-discussion
