Re: System slow down from udev

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Wednesday, May 29, 2013 03:49:38 PM Yinghai Lu wrote:
> On Wed, May 29, 2013 at 2:34 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > On Wednesday, May 29, 2013 01:13:46 PM Yinghai Lu wrote:
> >> On Wed, May 29, 2013 at 4:29 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> >> > On your systems the processor driver is built-in.  Any chance to build it as
> >> > a module and see if that helps?
> >>
> >> it CONFIG_ACPI_PROCESSOR it not set in the config
> >> the boot get to normal speed.
> >
> > Well, if it is not set at all, there won't be problems with it. :-)
> >
> > I've tested my linux-next branch on OpenSUSE 11.3 both with the processor
> > driver built in and modular and I'm not able to reproduce the issue you're
> > seeing.
> >
> > Moreover, I'm not sure if user space is involved here at all, because the
> > problem triggers for you when all of the relevant kernel code is non-modular.
> >
> > With the processor driver enabled, when the slowdown happens, are the systems
> > usable enough to get some debug info out of them?
> 
> please check the bootchart data.
> 
> looks like it take 200s if no acpi_processor ...
> otherwise will take 800s or more.

Well, something's fishy for sure.

To my eyes it looks like we're getting lots of notifications related to the
processor driver and that generates a lot of workqueue load.

Can you please get /proc/interrupts from both cases and the output of
"find /sys/firmware/acpi/interrupts/ -print -exec cat {} \;"?

Also please send the output of "ls -l /sys/devices/system/cpu/cpu*" with the
processor driver present.

Thanks,
Rafael


-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.