HTT/SMP servers instability on 5.3-STABLE

[John Baldwin]

On Friday 10 December 2004 03:48 pm, Kris Kennaway wrote:
> On Fri, Dec 10, 2004 at 05:58:06AM -0600, klr at 6s-gaming.com wrote:
> > I've heard it can penalize performance because the scheduler isn't
> > optimized for logical CPUs.  Does having HTT enabled impacts the
> > stability of the system?
>
> No.

Actually, for 5.3 it does.  HEAD has the problem fixed, not sure about 
RELENG_5 yet, but due to the way IPIs are done in 5.3, having more than 2 
CPUs can be very destabilizing, so disabling HTT on a 2-way system so that it 
goes from 4 CPUs to 2 CPUs can help stability very much.

-- 
John Baldwin <jhb at FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve"  =  http://www.FreeBSD.org