On Sat, Oct 18, 2008 at 5:05 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > On Sat, 18 Oct 2008, Vegard Nossum wrote: >> I was testing kmemcheck in -next and found that the machine can suddenly >> hang for no apparent reason. >> >> This is what I did: >> >> - boot USB pen-drive (contains root fs) >> - after the system has been up (and stable) for a long while, I >> inserted/removed quickly a few other pen-drives >> >> Now all new processes which access the filesystem will hang indefinitely. >> See output of SysRq-l and SysRq-w below. > > Which device holds your root fs? I'd guess it was 1-6, since that > device has address 2. > >> usb 1-2: USB disconnect, address 12 >> usb 1-6: reset high speed USB device using ehci_hcd and address 2 >> usb 1-6: device descriptor read/64, error -110 >> usb 1-6: device descriptor read/64, error -110 >> usb 1-6: reset high speed USB device using ehci_hcd and address 2 >> usb 1-6: device descriptor read/64, error -110 >> usb 1-6: device descriptor read/64, error -110 >> usb 1-6: reset high speed USB device using ehci_hcd and address 2 >> usb 1-6: device not accepting address 2, error -110 >> hub 1-0:1.0: unable to enumerate USB device on port 2 >> usb 1-6: reset high speed USB device using ehci_hcd and address 2 >> usb 1-6: device not accepting address 2, error -110 >> usb 1-6: USB disconnect, address 2 > > The log shows a disconnect on usb 1-2 and a failed reset followed by a > logical disconnect on usb 1-6. If either of those was the root fs, > it's understandable that your system would hang. After all, you can't > expect it to do much when the root fs is gone. I agree :-) The root fs was plugged in all along, and I didn't touch it. The root fs was this (from same log): usb 1-6: configuration #1 chosen from 1 choice usb 1-6: New USB device found, idVendor=090c, idProduct=1000 usb 1-6: New USB device strings: Mfr=1, Product=2, SerialNumber=3 usb 1-6: Product: DISK 2.0 usb 1-6: Manufacturer: USB usb 1-6: SerialNumber: 9GXZ0MZLH75GCAH7 So it seems that maybe the disk itself is bad? But it is also an odd coincidence that it would only happen when (re-)plugging other USB devices? Vegard -- "The animistic metaphor of the bug that maliciously sneaked in while the programmer was not looking is intellectually dishonest as it disguises that the error is the programmer's own creation." -- E. W. Dijkstra, EWD1036 -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
