Re: igb regression (interface hang) with latest -git

From: Stephen Hemminger
Date: Wed Jan 21 2009 - 19:04:41 EST


On Wed, 21 Jan 2009 14:51:07 -0800
"Duyck, Alexander H" <alexander.h.duyck@xxxxxxxxx> wrote:

> Rafael J. Wysocki wrote:
> > On Wednesday 21 January 2009, Ingo Molnar wrote:
> >>
> >> * Rafael J. Wysocki <rjw@xxxxxxx> wrote:
> >>
> >>> On Wednesday 21 January 2009, Ingo Molnar wrote:
> >>>>
> >>>> * Ingo Molnar <mingo@xxxxxxx> wrote:
> >>>>
> >>>>>> One other piece of info (in addition to what Bruce requested)
> >>>>>> that would be useful is after you've done ifconfig eht0 up, cat
> >>>>>> /proc/interrupts | grep eth0 and send that output (I want to see
> >>>>>> your MSI-X configuration).
> >>>>>
> >>>>> here it is:
> >>>>>
> >>>>> 79: 35 0 9836 7451 1197
> >>>>> 1360 766 0 2196 995 770
> >>>>> 0 2051 863 4714 1879 PCI-MSI-edge
> >>>>> eth0-tx-0 80: 2335 0 2718 3651
> >>>>> 5024 9850 533 0 1405 1095
> >>>>> 0 0 4421 1229 0 2002
> >>>>> PCI-MSI-edge eth0-tx-1 81: 33 0 0
> >>>>> 5478 1125 6585 4865 6306 0
> >>>>> 0 0 714 3757 0 2662
> >>>>> 1020 PCI-MSI-edge eth0-tx-2 82: 21 1428
> >>>>> 3136 3783 4249 6833 0 0
> >>>>> 4175 0 0 1465 1940 1780
> >>>>> 6286 0 PCI-MSI-edge eth0-tx-3 83: 40
> >>>>> 0 0 4788 0 1486 0
> >>>>> 7185 3998 8637 1409 6785 0
> >>>>> 0 0 10060 PCI-MSI-edge eth0-rx-0 84:
> >>>>> 70 1441 2606 1342 0 1678
> >>>>> 4301 1839 0 6507 6910 16470
> >>>>> 0 1484 1004 0 PCI-MSI-edge eth0-rx-1
> >>>>> 85: 40 1368 0 3560 5022
> >>>>> 2040 5 1719 0 2037 956
> >>>>> 40 0 17264 6456 2833 PCI-MSI-edge
> >>>>> eth0-rx-2 86: 44 414 5 1164
> >>>>> 30 4513 4595 1542 0 10033
> >>>>> 1151 0 4961 4203 0 10703
> >>>>> PCI-MSI-edge eth0-rx-3 87: 1 0 0
> >>>>> 0 0 0 0 0 0
> >>>>> 0 0 0 0 0 0
> >>>>> 0 PCI-MSI-edge eth0
> >>>>
> >>>> btw., i turned off CONFIG_PCI_MSI and that worked around the
> >>>> interface
> >>>> hang - the box has 40 minutes uptime now and still no hang. (it
> >>>> would hang
> >>>> within 5 minutes previously)
> >>>>
> >>>> can test the revert of any of these commits:
> >>>>
> >>>> e42e4ba: igb: fix anoying type mismatch warning on rx/tx queue
> >>>> sizing 8d25332: igb: Fix build warning when DCA is disabled.
> >>>> 26bc19e: igb: re-order queues to support cleaner use of ivar on
> >>>> 82576 0e014cb: igb: defeature tx head writeback
> >>>> 678c610: drivers/net/igb: remove dead code (function
> >>>> 'igb_read_pci_cfg') 908a7a1: net: Remove unused netdev arg from
> >>>> some NAPI interfaces.
> >>>> ea943d4: igb: fixup AER with proper error handling
> >>>> 5e8427e: igb: Correctly determine pci-e function number in virtual
> >>>> environment
> >>>> b4557be: igb: update handling of RCTL for smaller buffer sizes
> >>>> cb7b48f: igb/e1000e: Naming interrupt vectors
> >>>> 40a914f: igb: Add support for pci-e Advanced Error Reporting
> >>>> 527d47c: igb: link up/down messages must follow a specific format
> >>>> 5b9ab2e: Merge branch 'master' of
> >>>> master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 69d728b:
> >>>> igb: loopback bits not correctly cleared from RCTL register
> >>>> 9b07f3d: igb: remove unneeded bit refrence when enabling jumbo
> >>>> frames
> >>>> f5f4cf0: igb: do not use phy ops in ethtool test cleanup for
> >>>> non-copper parts 0082982: netdev: add more functions to netdevice
> >>>> ops 68fd991: igb: Fix tx/rx_ring_count parameters for igb on
> >>>> suspend/resume/ring resize b2d5653: igb: simplify swap in
> >>>> clean_rx_irq if using packet split 2e5c692: igb: convert to
> >>>> net_device_ops 198d6ba: Merge branch 'master' of
> >>>> master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 4cf1653:
> >>>> netdevice: safe convert to netdev_priv() #part-2
> >>>> babcda7: drivers/net: Kill now superfluous ->last_rx stores.
> >>>> 7c510e4: net: convert more to %pM
> >>>>
> >>>> i had a quick look at all of them but none seem to have a direct
> >>>> connection to MSI-X interrupt generation.
> >>>>
> >>>> There's a couple of ones that could have side effects:
> >>>>
> >>>> Maybe this one:
> >>>>
> >>>> 26bc19e: igb: re-order queues to support cleaner use of ivar on
> >>>> 82576
> >>>>
> >>>> due to its sheer commit size and due to its impact on the hw
> >>>> programming.
> >>>>
> >>>> or:
> >>>>
> >>>> 0e014cb: igb: defeature tx head writeback
> >>>>
> >>>> Might have some side-effect on tx-completion IRQs and might tickle
> >>>> firmware bugs?
> >>>>
> >>>> Or:
> >>>>
> >>>> 5e8427e: igb: Correctly determine pci-e function number in
> >>>> virtual environment
> >>>>
> >>>> while it should have no impact on a native kernel, it does change
> >>>> the PCI
> >>>> config space access sequences.
> >>>>
> >>>> Or maybe:
> >>>>
> >>>> 69d728b: igb: loopback bits not correctly cleared from RCTL
> >>>> register
> >>>>
> >>>> as this impacts the PCI programming too.
> >>>>
> >>>> But ... i dont really know this code so i'm guessing around.
> >>>
> >>> Well, AER (Advanced Error Reporting) is currently broken w/ MSI-X,
> >>> so maybe this one:
> >>>
> >>> 40a914f: igb: Add support for pci-e Advanced Error Reporting
> >>
> >> ah, yeah, that makes sense. I discarded that commit because i was
> >> unsure whether this box has AER and the boot log said:
> >>
> >> calling aer_service_init+0x0/0x20 @ 1
> >> initcall aer_service_init+0x0/0x20 returned 0 after 61 usecs
> >>
> >> shouldnt it have printed something if AER was available?
> >
> > The driver doesn't seem to print anything on success as far as I can
> > see. It only reports faliures, apparently.
> >
> > Thanks,
> > Rafael
>
> I have noticed that too after going through the logs on one of the Nahalem systems I have here. It might just be best to disable AER in the kernel if it isn't functional on the system and see if that helps to clear up the issue.
>
> I am leaning torward some external influence affecting the igb driver. Of the changes I made the only one I could really think of that would have much affect on MSI-X interrupts would be queue reordering, but that should have little to no effect on 82575 parts as it was intended to only reorder queues on 82576, in addition I would expect an immediate issue since the configuration is pretty much static after the queues are allocated. The only other patch that could even have a remote possiblity would be the TX head writeback defeature, but I would only expect that one to affect tx.
>
> Thanks,
>
> Alex

AER wont work unless PCI supports MMCONFIG.
This is a real problem, that I ended up giving up on standard pci access for sky2.
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