Hi irq usage . using dell 2950 (dual quad core cpus) 5.0rc4 with intel 82576 based 4 port card pci express - i htought this was msi-x and should not eat up so many irqs and cpu cycles . doing 75kpps -90kpps out and 90kpps in . multicpu is on

total-memory: 1943140KiB
cpu: "Intel(R)"
cpu-count: 8
cpu-frequency: 2494MHz
cpu-load: 49%

/system resource irq?
# IRQ USERS CPU ACTIVE-CPU COUNT
0 1 i8042 auto 7 2
1 4 serial auto 7 4
2 9 acpi auto 7 0
3 12 i8042 auto 7 4
4 14 ide0 auto 7 0
5 20 usb5 auto 7 86
usb3
6 21 usb4 auto 7 23
usb2
usb1
7 23 ata_piix auto 7 74197
8 40 aerdrv auto 7 0
9 41 aerdrv auto 7 0
10 42 aerdrv auto 7 0
11 43 aerdrv auto 7 0
12 44 aerdrv auto 7 0
13 45 aerdrv auto 7 0
14 51 ether1 0 0 4
15 52 eth2-TxRx-0 auto 7 17781
16 53 eth2-TxRx-1 auto 7 17438
17 54 eth2-TxRx-2 auto 7 17464
18 55 eth2-TxRx-3 auto 7 17409
19 56 eth2-TxRx-4 auto 7 17453
20 57 eth2-TxRx-5 auto 7 17410
21 58 eth2-TxRx-6 auto 7 17410
22 59 eth2-TxRx-7 auto 7 17779
23 60 ether5 4 4 41431
24 61 ether2 5 5 1
25 62 eth3-TxRx-0 1 1 45961
26 63 eth3-TxRx-1 auto 7 21480
27 64 eth3-TxRx-2 auto 7 27693
28 65 eth3-TxRx-3 auto 7 62143
29 66 eth3-TxRx-4 auto 7 17208
30 67 eth3-TxRx-5 auto 7 87162
31 68 eth3-TxRx-6 auto 7 41112
32 69 eth3-TxRx-7 auto 7 95679
33 70 ether6 auto 6 26743
34 71 ether3 2 2 1
35 72 eth4-TxRx-0 auto 6 16720
36 73 eth4-TxRx-1 auto 6 15340
37 74 eth4-TxRx-2 auto 0 66215
38 75 eth4-TxRx-3 auto 1 46466
39 76 eth4-TxRx-4 auto 5 75324
40 77 eth4-TxRx-5 auto 6 34156
41 78 eth4-TxRx-6 auto 1 59448
42 79 eth4-TxRx-7 auto 5 61407
43 80 ether4 3 3 1
44 81 eth5-TxRx-0 auto 6 2888
45 82 eth5-TxRx-1 auto 4 49941
46 83 eth5-TxRx-2 auto 6 30318
47 84 eth5-TxRx-3 auto 6 42206
48 85 eth5-TxRx-4 auto 6 30322
49 86 eth5-TxRx-5 auto 0 66746
50 87 eth5-TxRx-6 auto 4 87596
51 88 eth5-TxRx-7 auto 7 99130

CPU LOAD IRQ DISK
0 47% 46% 0%
1 50% 50% 0%
2 35% 37% 0%
3 41% 43% 0%
4 38% 40% 0%
5 38% 40% 0%
6 79% 81% 0%
7 63% 65% 0%
/system resource cpu>

monitor traffic aggregate shows

rx-packets-per-second: 166270
rx-drops-per-second: 0
rx-errors-per-second: 0
rx-bits-per-second: 282.9Mbps
tx-packets-per-second: 166648
tx-drops-per-second: 0
tx-errors-per-second: 0
tx-bits-per-second: 271.6Mbps

/system resource pci partial paste below shows as 82576 based chip which does support msi-x !

# DEVICE VENDOR NAME IRQ
1 0d:00.1 Intel Corporation 82576 Gigabit Network Connection (rev: 1) 6
2 0d:00.0 Intel Corporation 82576 Gigabit Network Connection (rev: 1) 10
3 0c:00.1 Intel Corporation 82576 Gigabit Network Connection (rev: 1) 11
4 0c:00.0 Intel Corporation 82576 Gigabit Network Connection (rev: 1) 11
8 07:00.0 Broadcom Corporation NetXtreme II BCM5708 Gigabit Ethernet (rev: 18) 11
9 06:00.0 Broadcom EPB PCI-Express to PCI-X Bridge (rev: 195) 0
10 05:01.0 Intel Corporation 6311ESB/6321ESB PCI Express Downstream Port E2 (rev: 1) 0
11 05:00.0 Intel Corporation 6311ESB/6321ESB PCI Express Downstream Port E1 (rev: 1) 0
12 04:00.3 Intel Corporation 6311ESB/6321ESB PCI Express to PCI-X Bridge (rev: 1) 0
13 04:00.0 Intel Corporation 6311ESB/6321ESB PCI Express Upstream Port (rev: 1) 0
14 03:00.0 Broadcom Corporation NetXtreme II BCM5708 Gigabit Ethernet (rev: 18) 11
15 02:00.0 Broadcom EPB PCI-Express to PCI-X Bridge (rev: 195) 0


So what do i do to bring irq load down ? None of the change logs in the latest since rc4 suggest anything to do with irq/msi-x have been done

Anybody know how to reduce the IRQ usage. I have put in most of the information in the first post... Please help

Upgraded to 5.4 but no use still have High irq usage
I did notice that some of our servers behind are sending high amount of udp packets but the router is still only handling 100kpps IN + 100kpps OUT with 8 cores we should have plenty of speed to spare. IRQ utilization is too much. Isnt there any machine where irq using the cpu can be reduced dramatically?

set the irq to different number of proccesor (from 0 to 7), change the "auto" to number of cpu on ethernet interfacec and tx-rx queue

so just randomly split the load across instead of using auto?p
Should I setup etherx interface on a separate cpu and tx-rx on separate cpu . eg
ether1 on cpu 0
eth1-rx1 on cpu1
eth1-rx2 on cpu2
xxxxx- and so on ?

I did try something but that didnt help too much.. the packets are so small and too many..