Re: Wierd context-switching issue on Xeon

Josh Berkus wrote:
> Tom,
>
> > So in the short term I think we have to tell people that Xeon MP is not
> > the most desirable SMP platform to run Postgres on.  (Josh thinks that
> > the specific motherboard chipset being used in these machines might
> > share some of the blame too.  I don't have any evidence for or against
> > that idea, but it's certainly possible.)
>
> I have 3 reasons for thinking this:
> 1) the ServerWorks chipset is present in the fully documented cases that we
> have of this problem so far.   This is notable becuase the SW is notorious
> for poor manufacturing quality, so much so that the company that made them is
> currently in receivership.   These chips were so bad that Dell was forced to
> recall several hundred of it's 2650's, where the motherboards caught fire!
> 2) the main defect of the SW is the NorthBridge, which could conceivably
> adversely affect traffic between RAM and the processor cache.
> 3) XeonMP is a very popular platform thanks to Dell, and we are not seeing
> more problem reports than we are.
>
> The other thing I'd like your comment on, Tom, is that Dirk appears to have
> reported that when he installed a non-bigmem kernel, the issue went away.

I have BSD on a SuperMicro dual Xeon, so if folks want another
hardware/OS combination to test, I can give out logins to my machine.

    http://candle.pha.pa.us/main/hardware.html

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