"Igor Shmukler" shmukler@mail.ru writes:
I remember reading in that very paper that - no proof that Mach based systems give only about 5% degradation was found, thus it is not being concedered a valid statement.
Do you mean this statement:
"We found no substantiation for the ``common knowledge'' that early Mach3.0-based Unix single-server implementations achieved a performance penalty of only 10% compared to bare Unix on the same hardware. For newer hardware, [9] reports penalties of about 50%." (related work chapter of "The Performance of micro-Kernel-Based Systems", http://os.inf.tu-dresden.de/pubs/sosp97/)
The Problem was that reviewers of the papers pointed out that Mach-based Unix-single-servers have a penalty of 10% without providing any reference to a conference paper. So we asked around, contacted people who had worked on Mach, but nobody was able to confirm the 10% penalty. Therefore we added this statement to the related work section.
Then comparison benchmarks are being given (though never analyzed). Extending same logic, I could say following: Paper is out, but due to lack of independently verified results and/or infrustrure required to complete such evaluation, results should not seen as valid.
We would have been happy to provide anyone with a copy of our test environment if anybody would have asked for it.
And it isn't the same logic. The problem was that some people said, that Mach based Unix-Servers had only 10% performance penalty without providing us with any performance numbers or references to papers. In contrast we compared two micro kernel based implementations of Linux running on the same hardware and published the results.
Farid said that he at some point compiled (more than once) mklinux for x86. Perhaps, would be worth doing it again, otherwise often seen claim that l4 is better microkernel, is more like rant.
Does that mean, you consider the published results as invalid? That we published numbers we didn't measure? At least the cited paper of M. Condict et al confirms our aim benchmark results.
I did not mean to offend anyone, but just trying to see which claims are valid and which are just wishful thinking.
Hope I was able to answer some of your questions.
regards, Jean