Re: sky2 panic in 2.6.32.1 under load (new oops)

From: Michael Breuer
Date: Fri Jan 01 2010 - 12:47:14 EST


More results... Seems that this is related to the tty (or maybe vt or maybe console) driver. I had disabled mingetty on tty1 as a workaround to a Fedora/KDE issue. When I reenabled it, I was then able to recreate this problem (sky2) in runlevel 3.

Retesting, it seems that the following conditions must be met in order for the interrupt errors to happen:

1) mingetty running on tty1 before the start of the test run
2) High sustained incoming load - 25MB/sec or more (as reported by nethogs)
3) I've only been able to recreate this using samba & a Windows 7 backup - but there could be other triggers

As it happens, much of my other data all came down to mingetty starting or not starting on tty1 at specific points of test preparation. At this point I can recreate 100% of the time if I ensure that there is a mingetty running on tty1, regardless of runlevel; and I can not recreate 100% of the time when there is no mingetty running on tty1 at the start of the test. The results do not change if I start or stop mingetty on tty1 during the test. It's possible that X running on tty1 may also trigger the issue, but I haven't tested that. Note that running mingetty on the other tty's does not affect the outcome of the test. The test is also unaffected if I chvt to or away from tty1 before the test. I do not have to be logged in at the console (on any vt) to trigger the issue.

In a nutshell, to recreate: make sure there is a mingetty running on tty1, blast traffic into the system on eth0 (sky2).




On 12/31/2009 1:09 PM, Michael Breuer wrote:
Did some more digging today... Haven't nailed it, but there's something going on with X and tty...

Among other things, when I telinit 3 && telinit 5 the tty keeps switching between 7 and 8 (nothing else running on either tty). It would appear that somehow the tty deallocation isn't complete when X restarts. Also, X grabbing a tty seems to be a requisite step in recreating the sky2 issue.

On 12/30/2009 1:10 PM, Stephen Hemminger wrote:
On Wed, 30 Dec 2009 10:40:56 -0500
Michael Breuer<mbreuer@xxxxxxxxxx> wrote:

Dec 30 10:37:14 mail kernel: sky2 0000:06:00.0: error interrupt
status=0x40000008
Dec 30 10:37:14 mail kernel: sky2 Tx ring pending=31...40 report=35 done=35
Dec 30 10:37:14 mail kernel: 30: 0x0: 0xeb50c0ca(9014)
Dec 30 10:37:14 mail kernel: 32: 0x0: 0xeb5080ca(9014)
Dec 30 10:37:14 mail kernel: 34: 0x0: 0xeb5040ca(9014)
Dec 30 10:37:14 mail kernel: 36: 0x0: 0xeb5000ca(9014)
Dec 30 10:37:14 mail kernel: 38: 0x0: 0xeb4fc0ca(9014)
You must be using 9K MTU. Do you see the problem with smaller
MTU?

Dec 30 10:37:14 mail kernel: sky2 0000:06:00.0: error interrupt
status=0x40000008
Dec 30 10:37:14 mail kernel: sky2 Tx ring pending=87...92 report=89 done=91
Dec 30 10:37:14 mail kernel: 86: 0x0: 0xeafd80ca(9014)
Dec 30 10:37:14 mail kernel: 88: 0x0: 0xeafd40ca(9014)
Dec 30 10:37:14 mail kernel: 90: 0x0: 0xeafd00ca(9014)
Dec 30 10:37:15 mail kernel: sky2 0000:06:00.0: error interrupt status=0x8
Dec 30 10:37:15 mail kernel: sky2 Tx ring pending=39...42 report=39 done=41
Dec 30 10:37:15 mail kernel: 38: 0x0: 0xe5fec0ca(9014)
Dec 30 10:37:15 mail kernel: 40: 0x0: 0xe5fe80ca(9014)
Dec 30 10:37:15 mail kernel: sky2 0000:06:00.0: error interrupt
status=0x40000008
Dec 30 10:37:15 mail kernel: sky2 Tx ring pending=117...124 report=119
done=119
Dec 30 10:37:15 mail kernel: 116: 0x0: 0xe5d6c0ca(9014)
Dec 30 10:37:15 mail kernel: 118: 0x0: 0xe5d680ca(9014)
Dec 30 10:37:15 mail kernel: 120: 0x0: 0xe5d660ca(5938)
Dec 30 10:37:15 mail kernel: 122: 0x0: 0xe5d640ca(4213)


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