On Tuesday, April 29, 2014 01:47:08 AM Peter Humphrey wrote: > On Monday 28 Apr 2014 13:32:05 I wrote: > > On Thursday 24 Apr 2014 13:57:19 I wrote: > > > So far I've done these things: > > > > > > 1. Wiped the whole system and restored from backup (heavy overkill, but > > > I > > > wanted everything to be in the same, consistent state). > > > 2. Run bad-blocks tests on all partitions (though all but / and /boot > > > are > > > in logical volumes - I don't know to what extent that will have affected > > > the results). > > > > --->8 > > > > Looking at bad-blocks again, I see from gkrellm that 'mkfs.ext4 -cc -L > > Atom > > /dev/vg7/atom' writes the test patterns to both the underlying physical > > disks, but it only reads back from one of them > > ... so it isn't much use on a virtual disk.
I thought the man-page for badblocks (it's a seperate utility) actually says it should be run on the physical disks? > Well, that was a long weekend. > > The symptoms grew stranger and stranger, until I eventually discovered a > problem with IRQ 16. > > /proc/interrupts includes this line: > 16: 0 302525 0 0 IO-APIC-fasteoi ehci_hcd:usb1, nouveau > > The source file /usr/src/linux/kernel/irq/spurious.c says: > > ...and suggests booting with irqpoll. > > So I added irqpoll to the kernel command line. It seemed to make no > difference at the time, but I haven't had any recurrence in the last two > days. I see though that, according to gkrellm, I have core temps of 52 - > 56C and the graphics card shows 59C. That shouldn't be hot enough to start > raising spurious interrupts: the nVidia web site says to expect around 105C > as a limit. Perhaps I should find a different slot for the Quadro FX580 > card, to separate it from the usb interface. Always a good idea, if possible. USB and Video are both heavily used items. > So, many hours and much rebuilding later, I've installed a new chroot for > the Atom and it seems to be working as expected. Actually, I reinstalled > the entire system to be safe, including re-creating the physical and > logical volumes on the two SATA disks. > > The question still remaining is what caused millions of spurious interrupts > over a period of a week or so and then subsided. This is an Asus P7P55D > motherboard (http://www.asus.com/Motherboards/P7P55D/). USB-mouse, keyboard,harddrive,flash-stick,.... ? Eg. anything plugged into USB can cause interrupts. Also, some mainboards have additional items pre-connected to the USB-bus. -- Joost
