Re: implemented features (Re: Decision time....)

["km b" <kmb810@xxxxxxxxx>]

On 04 Jun 2007 08:45:18 GMT, Rahul Siddharthan <rsidd120@gmail.com> wrote:
> I found this comment on Dmitri's blog possibly unfair, but somewhat
> reflecting my own perception as well:
> http://spetskod.blogspot.com/2007/05/immature-optimization.html#comment-8539868674748140994
>
> DragonFly was forked from FreeBSD-4 because of dissatisfaction with
> FreeBSD 5's approach to many things, including SMP.  But nothing
> visible to the user seems completed yet, especially not SMP.  And it
> looks like it won't be completed for 2.0 either.

Gr8 you're really far sighted.

> Today, nearly any new machine one buys will have at least 2 CPU cores,
> perhaps 4 or more.
>
> Also, nearly any new machine, whether AMD or Intel, will be 64-bit.
> On my own code (computational biology), using gcc, 32-bit binaries are
> 50% slower than 64-bit binaries.  (This is true of both gcc3 and gcc4.
> In fact, gcc 64-bit binaries are faster than 64-bit binaries generated
> by the Sun Studio compilers on amd64.)  That sort of speed difference
> is not trivial for the sort of work I do.

Please back your claims with empirical results. Please don't
generalize without finding out why 32-bit binaries are 50% slower than
64-bit binaries. Have you measured against pure 32-bit environment vs
pur 64-bit environment or just executing 32-bit binaries under 64-bit
environment. Have you measured the effect on the cache in different
environments (if you are using FreeBSD you can do so using PMC).

> So on a new machine I would really want to run a 64-bit, SMP OS.
> DragonFly is ruled out on both counts.

DragonFly is an SMP OS. 64-bit is desirable if you want to utilize
more than 4G address space.

> If one views DragonFly as a pet research project of Matt, Simon and
> others, this is fine.  But if it is to be a serious alternative to
> FreeBSD or other systems, shouldn't there be some focus on near-term
> goals that are actually useful to regular users, rather than ambitious
> ideas like a brand-new filesystem?  It seems to me that SMP and 64-bit
> support should be the first priorities.

Any near term "make it work" goals would make it another "hack it
yourself" os. You can use linux.

> If DragonFly were usable to me, I would be able to contribute to some
> things -- pkgsrc, testing device drivers -- though not to kernel-level
> stuff.  But at this point, I can't even run DragonFly on a new
> computer without crippling myself.

Go through the pain of trying it first and getting some help, where
you get stuck. We'll make it work.

> Rahul

kmb


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