Revision 6a4c24ec52128c1f57b7d2d24cf4dd13fc23f474 authored by Andrew Morton on 01 February 2007, 07:48:13 UTC, committed by Linus Torvalds on 02 February 2007, 00:22:41 UTC
Remove these recently-added warnings.  They don't tell us anythng very
interesting and Kumar says "On an embedded PPC reference system I see this
message 6 times when I've got no cards in the PCI slots."

Acked-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent cb7468e
Raw File
IRQ-affinity.txt

SMP IRQ affinity, started by Ingo Molnar <mingo@redhat.com>


/proc/irq/IRQ#/smp_affinity specifies which target CPUs are permitted
for a given IRQ source. It's a bitmask of allowed CPUs. It's not allowed
to turn off all CPUs, and if an IRQ controller does not support IRQ
affinity then the value will not change from the default 0xffffffff.

Here is an example of restricting IRQ44 (eth1) to CPU0-3 then restricting
the IRQ to CPU4-7 (this is an 8-CPU SMP box):

[root@moon 44]# cat smp_affinity
ffffffff
[root@moon 44]# echo 0f > smp_affinity
[root@moon 44]# cat smp_affinity
0000000f
[root@moon 44]# ping -f h
PING hell (195.4.7.3): 56 data bytes
...
--- hell ping statistics ---
6029 packets transmitted, 6027 packets received, 0% packet loss
round-trip min/avg/max = 0.1/0.1/0.4 ms
[root@moon 44]# cat /proc/interrupts | grep 44:
 44:          0       1785       1785       1783       1783          1
1          0   IO-APIC-level  eth1
[root@moon 44]# echo f0 > smp_affinity
[root@moon 44]# ping -f h
PING hell (195.4.7.3): 56 data bytes
..
--- hell ping statistics ---
2779 packets transmitted, 2777 packets received, 0% packet loss
round-trip min/avg/max = 0.1/0.5/585.4 ms
[root@moon 44]# cat /proc/interrupts | grep 44:
 44:       1068       1785       1785       1784       1784       1069       1070       1069   IO-APIC-level  eth1
[root@moon 44]#

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