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QNX Operating System/Discussion/OSTech/Platform limit/List of Posts
Forum Topic - Platform limit: (4 Items)
   
Update
Mario Charest
05/27/2008 3:49 PM
post8484
Platform limit   
The doc says, on x86, maxiimum number of CPU is 8. Is that still the case.  Does 6.4 increases that.  IBM is going to 
lend us a 4CPU/4core machine (16 processor) for 2 months... 

- Mario
Brian Stecher
05/28/2008 8:42 AM
post8504
Re: Platform limit   
On Tue, May 27, 2008 at 03:49:06PM -0400, Mario Charest wrote:
> The doc says, on x86, maxiimum number of CPU is 8. Is that still the 
> case.  Does 6.4 increases that.  IBM is going to lend us a 4CPU/4core 
> machine (16 processor) for 2 months... 

No, it's still 8 for the shipping product. You can compile a specialty
version off of Foundry27, by modifying the PROCESSORS_MAX definition
in services/system/smpswitch - but no higher than 32 since some of
the data structures would break after that point.

	Brian

-- 
Brian Stecher (bstecher@qnx.com)        QNX Software Systems
phone: +1 (613) 591-0931 (voice)        175 Terence Matthews Cr.
       +1 (613) 591-3579 (fax)          Kanata, Ontario, Canada K2M 1W8
Mario Charest
05/28/2008 11:54 AM
post8528
Re: Platform limit   
> On Tue, May 27, 2008 at 03:49:06PM -0400, Mario Charest wrote:
> > The doc says, on x86, maxiimum number of CPU is 8. Is that still the 
> > case.  Does 6.4 increases that.  IBM is going to lend us a 4CPU/4core 
> > machine (16 processor) for 2 months... 
> 
> No, it's still 8 for the shipping product. You can compile a specialty
> version off of Foundry27, by modifying the PROCESSORS_MAX definition
> in services/system/smpswitch - but no higher than 32 since some of
> the data structures would break after that point.
> 
> 	Brian
> 
> -- 
> Brian Stecher (bstecher@qnx.com)        QNX Software Systems
> phone: +1 (613) 591-0931 (voice)        175 Terence Matthews Cr.
>        +1 (613) 591-3579 (fax)          Kanata, Ontario, Canada K2M 1W8


Thanks. Out of curiousity, if it can support up to 32 why the 8 limit ?
Brian Stecher
05/28/2008 1:54 PM
post8532
Re: Platform limit   
On Wed, May 28, 2008 at 11:54:55AM -0400, Mario Charest wrote:
> Thanks. Out of curiousity, if it can support up to 32 why the 8 limit ?

We have a number of per-cpu static arrays, so incrementing the number
grows the procnto-smp size. Also, we haven't done a lot of testing
with higher numbers of CPU's so we're not sure of how our performance
scales in that range.

	Brian

-- 
Brian Stecher (bstecher@qnx.com)        QNX Software Systems
phone: +1 (613) 591-0931 (voice)        175 Terence Matthews Cr.
       +1 (613) 591-3579 (fax)          Kanata, Ontario, Canada K2M 1W8

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