Messages in this thread | | | Date | Thu, 11 Mar 2010 14:40:04 -0500 | From | Brian Haley <> | Subject | Re: BNX2: Kernel crashes with 2.6.31 and 2.6.31.9 |
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Michael Chan wrote: > On Thu, 2010-03-11 at 10:05 -0800, David Miller wrote: >> From: "Michael Chan" <mchan@broadcom.com> >> Date: Thu, 11 Mar 2010 09:49:56 -0800 >> >>> On Wed, 2010-03-10 at 18:09 -0800, Brian Haley wrote: >>>>>> I'm able to cause a netdev_watchdog timeout by changing the coalesce >>>>>> settings on my bnx2, I built a little test program for it: >>>>> Do you run this program in a loop? How quickly do you see the NETDEV >>>>> WATCHDOG? >>>> It's run once, and we see it almost immediately after ETHTOOL_SCOALESCE. >>> What's the difference between running the test program and doing ethtool >>> -C? Do you see the issue in either case? I don't see the issue here >>> with ethtool -C. >> Probably because the independent program runs faster and thus >> can trigger races more easily.
A customer provided some test code that triggered this hang, so I've just been using it. I just used ethtool and it happened too:
# ethtool -C eth0 rx-usecs 0 rx-frames 1 rx-usecs-irq 0 rx-frames-irq 1
If the interface is down, no problem.
> That's what I thought, I thought he was running it in a loop and > triggering some race condition. But he said he only ran it once. His > program gets the coalesce settings, sleeps for 5 seconds, and then sets > the coalesce settings.
The 5 seconds was there only because this was a snippet from a larger function that was doing a lot of ETHTOOL ioctl()'s, and I wanted to wait between each call to see which was causing this. Removing the sleep() still triggers the watchdog.
>> In any case, you should be trying to reproduce his problem with >> his test program since he went through the effort of providing >> one. > > I just tried it and cannot reproduce the problem. > > Brian, please provide more information. Thanks.
I can only reproduce this on one system out of many, so it's either a race condition or bad hardware. The only thing I can confirm at the moment is that it's the code at the bottom of bnx2_set_coalesce() that's causing it, I'm trying to go through all those codepaths now.
# lspci -vv -s 04:00 04:00.0 Ethernet controller: Broadcom Corporation NetXtreme II BCM5708 Gigabit Ethernet (rev 12) Subsystem: Hewlett-Packard Company NC373i Integrated Multifunction Gigabit Server Adapter Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV+ VGASnoop- ParErr+ Stepping- SERR+ FastB2B- DisINTx+ Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 64 (16000ns min), Cache Line Size: 64 bytes Interrupt: pin A routed to IRQ 65 Region 0: Memory at f6000000 (64-bit, non-prefetchable) [size=32M] [virtual] Expansion ROM at d0200000 [disabled] [size=2K] Capabilities: [40] PCI-X non-bridge device Command: DPERE- ERO- RBC=512 OST=8 Status: Dev=04:00.0 64bit+ 133MHz+ SCD- USC- DC=simple DMMRBC=512 DMOST=8 DMCRS=32 RSCEM- 266MHz- 533MHz- Capabilities: [48] Power Management version 2 Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot+,D3cold+) Status: D0 PME-Enable- DSel=0 DScale=1 PME- Capabilities: [50] Vital Product Data <?> Capabilities: [58] Message Signalled Interrupts: Mask- 64bit+ Queue=0/0 Enable+ Address: 00000000fee0100c Data: 4182 Kernel driver in use: bnx2 Kernel modules: bnx2
# ethtool -i eth0 driver: bnx2 version: 2.0.2 firmware-version: 1.9.6 bus-info: 0000:04:00.0
What other info would help?
-Brian
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