MSI or MSI-X
From Ye Ole Stash
Contents |
The Raw Facts
- All tests were done in a dev environment. Click the link if you need to know what kind of insanity that can mean.
- The irqbalance service will try and load balance IRQs across the processors in a system but this does not always work as advertised.
The Easy Way
- This is usually right but in the rare case of a issue with irqbalance, hardware, or other strange anomaly you always have the hard way below.
- Example of MSI based Ethernet with a IRQBALANCE deficit (note almost all the interrupts are on a single processors even those this is a 2 core w/HT)
# cat /proc/interrupts | grep eth0 58: 139 0 0 15731822 PCI-MSI eth0
- Example of a MSI system with typical IRQBALANCE in effect.
# cat /proc/interrupts | grep eth0 90: 31 0 0 139525 514071 0 35824642 4052 PCI-MSI eth0
- Example of MSI-X based Ethernet (note that the interrupts are on all 8 cores in this system and there is )
# cat /proc/interrupts | grep eth0 74: 25 3903239 5654184 5297430 0 3271555 6855593 6957270 PCI-MSI-X eth0-tx-0 82: 23 11233711 9044824 2479724 0 4212697 4454767 9507983 PCI-MSI-X eth0-rx-0 90: 24 5533313 5959329 5810220 0 7861393 6604786 6829478 PCI-MSI-X eth0-rx-1 98: 22 6029174 3976465 7754412 0 9013154 8969896 2810864 PCI-MSI-X eth0-rx-2 106: 24 6076860 4618086 11353620 0 2906385 6859038 7781512 PCI-MSI-X eth0-rx-3 114: 1 0 0 0 0 0 0 0 PCI-MSI-X eth0
The Hard Way
Using GlusterFS
- node0 (client) do a dd if=/dev/zero of=/mnt/gluster/sample-file-4 bs=1M count=10240
Using SSH
- scp
