Re: System slow down from udev

From: Rafael J. Wysocki
Date: Wed May 29 2013 - 20:12:00 EST


On Thursday, May 30, 2013 01:55:07 AM Rafael J. Wysocki wrote:
> 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@xxxxxxx> 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@xxxxxxx> 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.

Well, this is kind of a blind shot, but I'm wondering if the appended patch
makes any difference?

Rafael


---
drivers/acpi/processor_driver.c | 3 ---
1 file changed, 3 deletions(-)

Index: linux-pm/drivers/acpi/processor_driver.c
===================================================================
--- linux-pm.orig/drivers/acpi/processor_driver.c
+++ linux-pm/drivers/acpi/processor_driver.c
@@ -87,9 +87,6 @@ static void acpi_processor_notify(acpi_h
struct acpi_processor *pr;
int saved;

- if (device->handle != handle)
- return;
-
pr = acpi_driver_data(device);
if (!pr)
return;

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