Le lun 20/09/2004 à 16:31, Jonathan Corbet a écrit :
Jean Francois Martinez jfm512@free.fr wrote:
First of all it looks like the guy divided his 4GB disk in two 2G partitions and installed Reiser on one partition and EXT3 in the other. WRONG! Modern disks have more sectors in the outer, lower numbered tracks. Meaning that you will get higher throughput from hda1 than from hda2.
Wrong indeed. The same partition was used for all tests. One can give me a little credit, even if it hurts.
Sorry, when I saw you used a 2G partition on a 4G disk I thought you had cut in two halves, one for Reiser, the other one for EXT3.
He also compiled the kernel as a benchmark. 99% of times this is the touchstone for lack of proper thinking in benchmarking.
Because I benchmarked an actual task that my readers are likely to perform?
The other day I had a discussion with the sysadmin of another department and our common position was: 1) The state of the art in kernel building (ie use of modules and cpu detection by the installer) allows vendors to ship kernels whose performance is close enough to a custom built one the user should not need to bother with recompiling. 2) If the kernel you get out of the box is an underperformer then it is a _bug_. And we both refuse to fix the bad work of a vendor: if he doesn't fix the bug then he is out. So here you have two persons who administer several Linux and Unix boxes who never compile kernels but who run databases (both free and proprietary).
Look, the benchmarks in the LWN articles were a low-value exercise, just to get a rough feel for the performance benefits claimed by reiser4. I believe I succeeded in that goal. Among other things, I turned up the fact that, if you fail to create your files in the right order, performance suffers significantly - something which the Namesys marketing literature somehow failed to mention.
That is good.
Now forgive me a former statistician who tends to be pedantic (and harsh) about benchmarks.
jon
Jonathan Corbet Executive editor, LWN.net corbet@lwn.net