Also seeing 2 x quad-core system slower that 2 x dual core
Pete French
petefrench at ticketswitch.com
Fri Nov 30 03:33:53 PST 2007
> Yes, if the claim is that the hardware is absolutely identical apart
> from one having two quad-core CPUs instead of two dual-core, the next
> step is to disable half of the CPUs and confirm that the problem goes away.
Just comming back to this today, will do a side by side compare of the dmesg
later to make sure that they *are* identical as claimed, but the idea of
disabling half the CPU's is an excellent one!
Aha, brilliant idea!
> Check dmesg for the APIC numbers corresponding to the CPUs you want to
> disable and add the corresponding entries to /boot/loader.conf, e.g.:
You mean this bit?
FreeBSD/SMP: Multiprocessor System Detected: 8 CPUs
cpu0 (BSP): APIC ID: 0
cpu1 (AP): APIC ID: 1
cpu2 (AP): APIC ID: 2
cpu3 (AP): APIC ID: 3
cpu4 (AP): APIC ID: 4
cpu5 (AP): APIC ID: 5
cpu6 (AP): APIC ID: 6
cpu7 (AP): APIC ID: 7
> hint.lapic.1.disable="1"
> hint.lapic.3.disable="1"
> hint.lapic.5.disable="1"
> hint.lapic.7.disable="1"
gives me...
hint.lapic.1.disable="1"
hint.lapic.3.disable="3"
hint.lapic.5.disable="5"
hint.lapic.7.disable="7"
rebooting now to give it a try...
-pete.
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