mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-21 11:44:01 +08:00
1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
38 lines
1.3 KiB
Plaintext
38 lines
1.3 KiB
Plaintext
|
|
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]#
|
|
|