Re: Filesystem Tests

Timothy Miller
2003-08-06T23:24:55Z

Hans Reiser wrote:

> reiser4 cpu consumption is still dropping rapidly as others and I find
> kruft in the code and remove it. Major kruft remains still.

If a file system is getting greater throughput, that means the relevant
code is being run more, which means more CPU will be used for the
purpose of setting up DMA, etc. That is, if a FS gets twice the
throughput, it would not be unreasonable to expect it to use 2x the CPU
time.

Furthermore, in order to achieve greater throughput, one has to write
more intelligent code. More intelligent code is probably going to
require more computation time.

That is to say, if your FS is twice as fast, saying it has a problem
purely on the basis that it's using more CPU ignores certain facts and
basic logic.

Now, if you can manage to make it twice as fast while NOT increasing the
CPU usage, well, then that's brilliant, but the fact that ReiserFS uses
more CPU doesn't bother me in the least.