Re: System slow down from udev

From: Yinghai Lu
Date: Wed May 29 2013 - 22:12:22 EST


On Wed, May 29, 2013 at 5:20 PM, Rafael J. Wysocki <rjw@xxxxxxx> wrote:
> 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?

No difference. it's still slow.

>
>
> ---
> 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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