HTT/SMP servers instability on 5.3-STABLE]

[klr at 6s-gaming.com]

Hi,

I have a Dual Xeon 2.4 and a Dual Xeon 2.8 servers running with
HyperThreading, ACPI, and SMP enabled.

The 2.8 server won't stand for more than 5 days without crashing, and the
2.4 server was up 30 days crashed, now was up 12 days, and crashed.

I didn't have a debugging kernel, I'll be building one when the datacenter
reboots the server. I also don't have any panic messages.. I have,
however, a few questions:

- machdep.cpu_idle_hlt - I've seen a lot on google about this sysctl, but
still don't fully understand it. What does this sysctl really changes?

- HyperThreading - Do I really have a performance increase with HTT turned
on? 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?

- ACPI - I'll be disabling ACPI along with HTT to see if the server
doesn't crash for awhile. Is ACPI on 5.3-STABLE (around November 1st, it
was pre-release) still a problem?

Last but not the least, my 5.3-STABLE version is from a few days before
the release. Since I had created a few jails by then, I didn't upgrade the
system to use the -RELEASE. Was there any last-standing problem a few days
before the release that could be causing my instability problems?


Please share some common dual processor system knowledge, perhaps I'm
missing something really obvious and making these servers unstable.

Regards,

Hugo