Bug 446753 - Fedora 2.6.25.3-18 kernel does not use MSI for e1000e (82571)
Fedora 2.6.25.3-18 kernel does not use MSI for e1000e (82571)
Status: CLOSED NOTABUG
Product: Fedora
Classification: Fedora
Component: kernel (Show other bugs)
9
i686 Linux
low Severity medium
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Assigned To: Kernel Maintainer List
Fedora Extras Quality Assurance
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Depends On:
Blocks:
  Show dependency treegraph
 
Reported: 2008-05-15 16:55 EDT by Tom Sylla
Modified: 2008-05-16 10:12 EDT (History)
1 user (show)

See Also:
Fixed In Version:
Doc Type: Bug Fix
Doc Text:
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Clone Of:
Environment:
Last Closed: 2008-05-16 10:12:16 EDT
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CRM:
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oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---


Attachments (Terms of Use)
dmesg of fc9 (32.07 KB, text/plain)
2008-05-15 16:55 EDT, Tom Sylla
no flags Details
dmesg of vanilla (31.87 KB, text/plain)
2008-05-15 16:55 EDT, Tom Sylla
no flags Details
/proc/interrupts of fc9 (1.76 KB, text/plain)
2008-05-15 16:56 EDT, Tom Sylla
no flags Details
/proc/interrupts of vanilla (1.76 KB, text/plain)
2008-05-15 16:56 EDT, Tom Sylla
no flags Details

  None (edit)
Description Tom Sylla 2008-05-15 16:55:07 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 (2.6.25.3-18)
don't enable MSI for the Intel ethernet module. If I use vanilla 2.6.25.3, it
*does* use MSI. I would like to use MSI on this platform to allow flexibility
with sharing IRQs.

How reproducible:
Always.

Steps to Reproduce:
1. Boot F9 on a platform with an 82571 ethernet device.
2. look at /proc/interrupts
  
Actual results:
ethX uses IO-APIC-fasteoi.

Expected results:
ethX uses PCI-MSI-edge.

Additional info:
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.
Comment 1 Tom Sylla 2008-05-15 16:55:07 EDT
Created attachment 305540 [details]
dmesg of fc9
Comment 2 Tom Sylla 2008-05-15 16:55:43 EDT
Created attachment 305541 [details]
dmesg of vanilla
Comment 3 Tom Sylla 2008-05-15 16:56:22 EDT
Created attachment 305542 [details]
/proc/interrupts of fc9
Comment 4 Tom Sylla 2008-05-15 16:56:39 EDT
Created attachment 305543 [details]
/proc/interrupts of vanilla
Comment 5 Dave Jones 2008-05-16 10:12:16 EDT
boot with pci=msi
By default, we can't enable it, because the MSI support causes a lot of systems
to not even boot.

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