Re: [9fans] slow performance

[W B Hacker <wbh@conducive.org>]

Uriel wrote:
>> But a guess: ISTR seeing that the Plan9 kernel 'lacked a scheduler'.
>> That can be inconsequential for some situations, very important for 
>> others.
> 
> Could you please explain this? I'm still baffled as to what you mean.

No need. As said - stale info.  You've just clarified it, thanks!

But .. there IS a plethora of stale info and - perhaps worse - broken links - 
all over what Google finds as the Plan9 'universe'.

Sometimes hard to ascertain the date of the pages, as well.

> 
> As far as my limited knowledge goes, Plan 9 has had an SMP aware
> scheduler since ancient times[1](I think before 1st Ed), and in more
> recent times a real time scheduler[2] has been added.
> 

ACK. I've saved a couple of .pdf presentations discussion how it *could be*, but 
not clear to me that it *had been*.

> So I'm puzzled as to how Plan 9 could 'lack a scheduler'.

So am I.  Though my present interest is not so much lack of a scheduler, as 
curiousity as to how it prioritizes, (e.g. equivalents to 'nice', runlevels, et al).

> 
> I also would recommend at least taking a look at the performance
> section of http://plan9.bell-labs.com/sys/doc/9.html
> 
> uriel
> 
> [1] http://plan9.bell-labs.com/sys/doc/sleep.html
> [2] http://purl.org/utwente/fid/1149

All great stuff - and outlining what the benefits of Plan9 were/are/should be.

But dated. Been a while since a 100 MHz Irix was top dog, if ever was.

How much, if any, of what Plan9 is/was has been overtaken by events? And for 
better? Or for worse?

For example - Alef's parallizing features are noted, extolled, and:

"Although it is possible to write parallel programs in C, Alef is the parallel 
language of choice."

Which raises the question (in my own mind at least) as to how much and how well 
this has been preserved and extended in 'C' with Alef having left the building 
with Elvis.

And what penalty comes with the benefit of communication by text stream vs 
binary? And via a fs call (whether in cache/RAM or not), vs 
closer-to-the-CPU-core. Registers, even.

'Universality and 'portability' are perhaps not such a big deal when very few 
processor families are supported.

Granted - Plan9 does not, in most instances, attempt to do things in the same 
way - or even do them *at all* - that a 'big iron' OS, a *BSD or Linux might do, 
so head-to-head comparisons would certainly not be as easy as point and click 
(or ..mouse chord...).

And I *have* seen some impressive figures mentioned for time to boot a large 
grid from a cold start vs other OS'en.

But where can I/we find 'evidence'  - current evidence - that all this is more 
than a theoretical exercise?

A place where Plan9 holds the high ground in real-world use, so to speak.

Thanks for the patience...

Bill