Re: SMP broken on Dell PowerEdge 4100/200 under 2.6.0-testxx?

From: Nick Piggin
Date: Fri Dec 05 2003 - 21:51:17 EST

William Lee Irwin III wrote:

On Sat, Dec 06, 2003 at 10:32:45AM +0800, Colin Coe wrote:

This indicates to me that the processing load is being evenly distributed
accross the two processes. Under v2.6.0-testxx however, 'cat
/proc/interrupts' shows this:
[root@host root]# cat /proc/interrupts
0: 633122 30 IO-APIC-edge timer
1: 207 IO-APIC-edge i8042
2: XT-PIC cascade
4: 48 1 IO-APIC-edge serial
5: 449 1 IO-APIC-level eth1
10: 135 1 IO-APIC-level aic7xxx
11: 1447 1 IO-APIC-level eth0
12: 61 IO-APIC-edge i8042
14: IO-APIC-level CS46XX
15: 14982 1 IO-APIC-level megaraid

2.6 does balancing across packages, not logical cpus, so this will
happen and it will be largely harmless, except for what appears to
be some kind of bug where it's stealing the timer from logical cpu 1.

Although in this case Colin has 2 PPro 200s.

Colin - process load should be evenly distributed between CPUs, and this
is generally the most important thing. Big networking loads (most commonly)
can put a lot of time into processing interrupts though.

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