Linked by fran on Mon 30th Dec 2013 17:16 UTC
BeOS & Derivatives

In a blog post from Haiku developer Pawel Dziepak he describes the work he has been doing on improving processor support. Most notably removing the 8 processor limit. From the blog post:

The main scheduler logic has been completed and now I am concentrating mainly on bug fixes, adjusting tunables and some minor improvements. I also removed gSchedulerLock, a spinlock I mentioned in my last post, and replaced it with more fine grained locking. An new interfaces for cpufreq and cpuidle modules has been created together with a cpufreq module for Intel Sandy Bridge or newer cores and cpuidle module for all processors that support C-states and invariant TSC. Furthermore, IRQs (including MSI) can be now directed to an arbitrary logical processor. Implementation of inter-processor interrupts has been improved so that it avoids acquiring any lock if it is not necessary and supports multicast interrupts. And, last but not least, 8 processor limit has been removed.

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RE: Limitations ?
by terra on Tue 31st Dec 2013 08:34 UTC in reply to "Limitations ?"
Member since:

What is that 512MB limit? Rhapsody? BeOS had ~ 1GB limit. Whereas in Haiku AFAIK there is no such bogus limit.

Reply Parent Score: 2

RE[2]: Limitations ?
by Kochise on Tue 31st Dec 2013 09:40 in reply to "RE: Limitations ?"
Kochise Member since:

Yeah, sorry, the 1 GB limit. And also I had an AMD Athlon XP Palomino 1.4 GHz that couldn't neither run BeOS, even patched, nor YellowTab's ZetaOS, due to this limit and another regarding the boot procedure.

Still have my original YellowTab's ZetaOS CD and box ;)


Edited 2013-12-31 09:40 UTC

Reply Parent Score: 2

RE[3]: Limitations ?
by alphaseinor on Fri 3rd Jan 2014 16:04 in reply to "RE[2]: Limitations ?"
alphaseinor Member since:

So have you even tried to boot Haiku on this 1.4GHz machine?

Reply Parent Score: 1

RE[2]: Limitations ?
by henderson101 on Tue 31st Dec 2013 09:52 in reply to "RE: Limitations ?"
henderson101 Member since:

No, it was more complicated than that. BeOS had an overall 1GM memory limit, but as I recall it, the size of the RAM in your Video Card came in to that picture. So straight R5.03 with no patches really didn't like running with 1GB of RAM. I seem to recall that anything more than 768MB and a 256MB Graphics card being really problematic. Dano was even worse IIRC.

It was an artificial limitation though. The kernel was compiled with a static limitation over the RAM size, and had Be Inc released the source, it would have been possible to alter that. It's certainly what YellowTab did at any rate. I once asked JBQ about this, and he said it was something one of the engineers could have fixed pretty easily. The limitation was there because, as with much in IT, there had to be a limit. Back then, given the maximum memory slots counts and DIMM sizes, 1GB of RAM was fairly unfeasible on a desktop machine.

Reply Parent Score: 4

RE[3]: Limitations ?
by tylerdurden on Tue 31st Dec 2013 22:20 in reply to "RE[2]: Limitations ?"
tylerdurden Member since:

Still that an odd design decision for an OS written from scratch during the 90s.

Reply Parent Score: 3