Red Hat Bugzilla – Bug 446753
Fedora 220.127.116.11-18 kernel does not use MSI for e1000e (82571)
Last modified: 2008-05-16 10:12:16 EDT
Description of problem:
I have a platform with Opteron/HT2100/HT1000 with an Intel 82571 PCIe ethernet
controller. Both the original Fedora 9 kernel and the update today (18.104.22.168-18)
don't enable MSI for the Intel ethernet module. If I use vanilla 22.214.171.124, it
*does* use MSI. I would like to use MSI on this platform to allow flexibility
with sharing IRQs.
Steps to Reproduce:
1. Boot F9 on a platform with an 82571 ethernet device.
2. look at /proc/interrupts
ethX uses IO-APIC-fasteoi.
ethX uses PCI-MSI-edge.
I have attached dmesg and /proc/interrupts from the two kernels. I don't see
anything in dmesg that explains why MSI is not in use. Nothing should be
blacklisted, ethernet works fine in MSI mode on the vanilla kernel.
Created attachment 305540 [details]
dmesg of fc9
Created attachment 305541 [details]
dmesg of vanilla
Created attachment 305542 [details]
/proc/interrupts of fc9
Created attachment 305543 [details]
/proc/interrupts of vanilla
boot with pci=msi
By default, we can't enable it, because the MSI support causes a lot of systems
to not even boot.