irqpoll being ignored

ctrlbrk · 08-26-2011, 06:17 AM

Hi,

I did a clean install of LMDE which ships with 2.6.32 kernel. I had to pass irqpoll option via grub (modified /etc/default/grub to make it default) for things to work properly on my system, the culprit being a 3Ware 9690 RAID card it seems. All was well, except the performance of the RAID card was about half what it is under Windows.

Anyway, after an apt-get dist-upgrade later, and onward to kernel 2.6.39, irqpoll is no longer working.

My /etc/default/grub still has it as the default, I re-ran update-grub, and have also manually specified it via grub at the command line during boot.

Code:

# cat /etc/default/grub
# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.

GRUB_DEFAULT=0
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet irqpoll"
GRUB_CMDLINE_LINUX=""

Nothing works. Almost immediately after boot, I get the "irq ignored' warning, and "try using irqpoll" message. And my system is slower than a turtle. Takes about 10 minutes to boot instead of 20 seconds.

At this point, I've tried everything but not been able to get irqpoll to work (not be ignored) on 2.6.39. I'm running 2.6.32 again.

How do you determine if irqpoll is actually enabled (without looking at grub menu), but say after you are booted at shell.

That would be the basis for establishing what is happening, I would think.

Some help please?

ctrlbrk · 08-26-2011, 07:33 AM

I duplicated this using 3.0.0.1 as well. If I do a 'dmesg | grep irqpoll', it confirms the linux cmdline contains irqpoll, yet I also see the "try enabling irqpoll" error message, and my system is so slow it is completely unusable (took 10 minutes just to get to login prompt).

Back to 2.6.32, and works fine.

Hoping someone can help. I don't want to be stuck on 2.6.32 forever.

ctrlbrk · 08-31-2011, 01:57 AM

If anyone has ideas, I could really use some help. I don't want to be stuck on 2.6.32 forever.

Eadweard · 10-26-2011, 01:19 PM

I don't have a fix for your problem, yet, but I can tell you you're not alone; I think it's a regression in the kernel. From 2.6.39 on, irqpoll has stopped working for me, too. I have filed an Ubuntu bug:

https://bugs.launchpad.net/linux/+bug/855199

Bugzilla.kernel.org is still down, so I can't go there. I've emailed the maintainer and the kernel list. I haven't heard back there, yet; I think it can take several tries. I'm trying to learn more about the bug, and logging it at the bug page above. If you want to look in, or contribute, please do!

Good luck, to both of us.