asterisk users - May 2006 - hyperthreading and zaptel

My Dell 2800 Dual 64bit  Proc. machine came in with hyperthreading enabled.
(they call it virtual processor??)

I have been intending for a month to disable it.

Tonight, I rebooted, turned it off, and let the system come up.

zaptel loaded and asterisk loaded, but both of my t1s were red. (it is a TE411P)
/proc/interrupts looked OK, zttest gave OK numbers.
I doublechecked all of the files in case I changed something else accidentally.
I tried various combinations of unloading, loading the modules and ztcfg, etc.

Finally, I decided to turn hyperthreading back on, and everything is back to
normal.

Unless there is somewhere in CentOS 4.3 that has the processor count hardcoded
from the install, I am baffled by this.






-- 
-- 
Steven

http://www.glimasoutheast.org

Turning on hyperthreading may have changed the way interrupts are
routed. Were you using the same kernel (eg SMP kernel even with
hyperthreading disabled)? The BIOS may have configured things
differently too if you disabled it there.

I'm not sure, but you may be able to keep hyperthreading on in the BIOS
and boot into a UP kernel and have the same net effect as having ht
disabled.

You mention you have looked at /proc/interrupts, are there any
differences between the interrupt numbers assigned in the ht enabled and
ht disabled cases?

When the kernel boots, it dumps some info about IRQ routing, compare
those.

Maybe post /proc/interrupts and the relevant bits of the kernel boot
logs here if you aren't sure, someone might be able to spot something
out of the ordinary.

James
> -----Original Message-----
> From: asterisk-users-bounces@lists.digium.com [mailto:asterisk-users-
> bounces@lists.digium.com] On Behalf Of Steven
> Sent: Thursday, 4 May 2006 09:18
> To: asterisk-users@lists.digium.com
> Subject: [Asterisk-Users] hyperthreading and zaptel
> 
> My Dell 2800 Dual 64bit  Proc. machine came in with hyperthreading
> enabled. (they call it virtual processor??)
> 
> I have been intending for a month to disable it.
> 
> Tonight, I rebooted, turned it off, and let the system come up.
> 
> zaptel loaded and asterisk loaded, but both of my t1s were red. (it is
a
> TE411P)
> /proc/interrupts looked OK, zttest gave OK numbers.
> I doublechecked all of the files in case I changed something else
> accidentally.
> I tried various combinations of unloading, loading the modules and
ztcfg,
> etc.
> 
> Finally, I decided to turn hyperthreading back on, and everything is
back
> to normal.
> 
> Unless there is somewhere in CentOS 4.3 that has the processor count
> hardcoded from the install, I am baffled by this.
> 
> 
> 
> 
> 
> 
> --
> --
> Steven
> 
> http://www.glimasoutheast.org
> 
> 
> 
> 
> 
> _______________________________________________
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> 
> Asterisk-Users mailing list
> To UNSUBSCRIBE or update options visit:
>    http://lists.digium.com/mailman/listinfo/asterisk-users

Ummm... you can probably ignore most of what I said in my last email. I
just noticed that you said your machine has two physical processors, so
even with ht disabled you will still need an SMP kernel.

I'll pay more attention next time :)

James
> -----Original Message-----
> From: asterisk-users-bounces@lists.digium.com [mailto:asterisk-users-
> bounces@lists.digium.com] On Behalf Of Steven
> Sent: Thursday, 4 May 2006 09:18
> To: asterisk-users@lists.digium.com
> Subject: [Asterisk-Users] hyperthreading and zaptel
> 
> My Dell 2800 Dual 64bit  Proc. machine came in with hyperthreading
> enabled. (they call it virtual processor??)
> 
> I have been intending for a month to disable it.
> 
> Tonight, I rebooted, turned it off, and let the system come up.
> 
> zaptel loaded and asterisk loaded, but both of my t1s were red. (it is
a
> TE411P)
> /proc/interrupts looked OK, zttest gave OK numbers.
> I doublechecked all of the files in case I changed something else
> accidentally.
> I tried various combinations of unloading, loading the modules and
ztcfg,
> etc.
> 
> Finally, I decided to turn hyperthreading back on, and everything is
back
> to normal.
> 
> Unless there is somewhere in CentOS 4.3 that has the processor count
> hardcoded from the install, I am baffled by this.
> 
> 
> 
> 
> 
> 
> --
> --
> Steven
> 
> http://www.glimasoutheast.org
> 
> 
> 
> 
> 
> _______________________________________________
> --Bandwidth and Colocation provided by Easynews.com --
> 
> Asterisk-Users mailing list
> To UNSUBSCRIBE or update options visit:
>    http://lists.digium.com/mailman/listinfo/asterisk-users

> Finally, I decided to turn hyperthreading back on, and everything is back
> to normal.
> 
> Unless there is somewhere in CentOS 4.3 that has the processor count
> hardcoded from the install, I am baffled by this.
Was it on when * and zaptel was compiled?. Maybe the compiler produced HT
optimized binaries.  Just a thought?

Mark