Intel 82574L interface wedging on em 7.1.9/7.2.3 when MSIX enabled

[Arnaud Lacombe]

Hi,

On Fri, Oct 7, 2011 at 4:12 PM, Mike Tancsa <mike at sentex.net> wrote:
> On 10/7/2011 3:55 PM, Arnaud Lacombe wrote:
>>> When you disable MSI-X, you mean via hw.pci.enable_msix=0 across the
>>> board, or you disable multi-queue for the NIC, so it uses just one
>>> interrupt, rather than separate ones for xmit and recv ?
>>>
>> em(4)'s multiqueue is misleading. By default, with MSI-X enabled,
>> before AFAIK, April 2010 it used 2 (RX+TX) queue + 1, ie. 5 MSI-X
>> vectors[0]. After April 2010, it uses 1 * (RX+TX) queue +  1, ie. 3
>> MSI-X vectors. There is no logic for the driver to use 1 vector with
>> MSI-X enabled.
>
> Hi,
>        Very poor choice of wording on my part. I meant to say separate
> interrupts for the xmit and recv, as opposed to multiqueue which is
> quite different.
>
> On the server I used to see the issue with, it has 2 onboard NICs
>
> em0: <Intel(R) PRO/1000 Network Connection 7.2.3> port 0x4040-0x405f mem
> 0xb4500000-0xb451ffff,0xb4525000-0xb4525fff irq 16 at device 25.0 on pci0
> em0: Using an MSI interrupt
> em0: [FILTER]
> em0: Ethernet address: 00:15:17:ed:68:a5
>
> em1: <Intel(R) PRO/1000 Network Connection 7.2.3> port 0x2000-0x201f mem
> 0xb4100000-0xb411ffff,0xb4120000-0xb4123fff irq 16 at device 0.0 on pci11
> em1: Using MSIX interrupts with 3 vectors
> em1: [ITHREAD]
> em1: [ITHREAD]
> em1: [ITHREAD]
> em1: Ethernet address: 00:15:17:ed:68:a4
>
I'd assume that `em0' is not a 82574, whereas `em1' is.

 - Arnaud

> irq257: em0                    506496667        813
> irq258: em1:rx 0               296438098        476
> irq259: em1:tx 0               252033695        404
>
> Actually, I see it in Jason's email now that I re-read it.
> hw.em.enable_msix="0"
>
> However, with 7.1.9 this setting did not help me.
>
>
>        ---Mike
>
> --
> -------------------
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