Re: Benchmark (Phoronix): FreeBSD 9.0-RC2 vs. Oracle Linux 6.1 Server

From: Daniel Nebdal <dnebdal_at_gmail.com>
Date: Thu, 22 Dec 2011 00:26:17 +0100
On Wed, Dec 21, 2011 at 10:49 PM, Johan Hendriks <joh.hendriks_at_gmail.com> wrote:
> Alexander Leidinger schreef:
>>
>> Hi,
>>
>> while the discussion continued here, some work started at some other
>> place. Now... in case someone here is willing to help instead of talking,
>> feel free to go to http://wiki.freebsd.org/BenchmarkAdvice and have a look
>> what can be improved. The page is far from perfect and needs some additional
>> people which are willing to improve it.
>>
>> This is only part of the problem. A tuning page in the wiki - which could
>> be referenced from the benchmark page - would be great too. Any volunteers?
>> A first step would be to take he tuning-man-page and wikify it. Other tuning
>> sources are welcome too.
>>
>> Every FreeBSD dev with a wiki account can hand out write access to the
>> wiki. The benchmark page gives contributor-access. If someone wants write
>> access create a FirstnameLastname account and ask here for
>> contributor-access.
>>
>> Don't worry if you think your english is not good enough, even some
>> one-word notes can help (and _my_ english got already corrected by other
>> people on the benchmark page).
>>
>> Bye,
>> Alexander.
>
> Nice page, but one thing i do not get is the following.
>
> [quote]
> If you compare FreeBSD / GCC 4.2.1 against, for example, Ubuntu / GCC 4.7
> then the results are unlikely to tell you anything meaningful about FreeBSD
> vs Ubuntu.
> [/quote]
>
> That is a little strange in my opinion.
> It tells me that FreeBSD falls more and more behind on Linux.
> The reason is or could be that FreeBSD cannot or will not include GCC 4.7
> and that FreeBSD will not be on par with Linux anymore.
(...)

It does, though? It's in ports. The system compiler is for the system,
but if you're compiling ports or standalone software you certainly can
- and sometimes must - use something else. The point of that section
seems to be "if you're compiling userland software to compare, at
least compile it with the same compiler, unless that's what you want
to benchmark". Sensible enough.

As for what the kernel is compiled with, I doubt that will have the
same kind of effect as what the user software is compiled with. The
kernel is compiled with very conservative settings anyway, and I don't
think it really does much of the kind of heavy computation that
benefits the most from better compilers.

The most interesting part is probably the effect on the userland
libraries. Has anyone done any tests on how much of an effect on user
software performance it has if you change the compiler for the
libraries in the base system? (I would guess "not massive", but this
is one of those things where some numbers wouldn't hurt).

Oh, and remember that clang also works as a system compiler, and we're
definitely not stuck on an old version of that. It produces code with
performance comparable to gcc today, and I doubt it'll fall horribly
behind in the foreseeable future.


-- 
Daniel Nebdal
Received on Wed Dec 21 2011 - 22:26:19 UTC

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