Re: System slow down from udev

From: Yinghai Lu
Date: Thu May 30 2013 - 13:49:29 EST


On Thu, May 30, 2013 at 10:42 AM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
> On Thu, May 30, 2013 at 9:36 AM, Rafael J. Wysocki <rjw@xxxxxxx> wrote:
>> On Thursday, May 30, 2013 04:45:35 PM Rafael J. Wysocki wrote:
>>> On Thursday, May 30, 2013 04:34:51 PM Rafael J. Wysocki wrote:
>> [...]
>>> >
>>> > I'll try to dig deeper locally in the meantime.
>>>
>>> Actually, I think I know what the problem is, but I need some more time to
>>> debug it. Fortunately, I'm able to see some symptoms. :-)
>>
>> OK, one fix is appended, but there still is one more bug I need to investigate.
>>
>> Please check if this one helps, though.
>
> yes, that fix the problem.
>
>
>>
>> Thanks,
>> Rafael
>>
>>
>> ---
>> drivers/acpi/acpi_processor.c | 5 +++++
>> drivers/acpi/processor_driver.c | 3 ---
>> 2 files changed, 5 insertions(+), 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
>> @@ -78,9 +78,6 @@ static struct device_driver acpi_process
>> .remove = acpi_processor_stop,
>> };
>>
>> -DEFINE_PER_CPU(struct acpi_processor *, processors);
>> -EXPORT_PER_CPU_SYMBOL(processors);
>> -
>> static void acpi_processor_notify(acpi_handle handle, u32 event, void *data)
>> {
>> struct acpi_device *device = data;
>> Index: linux-pm/drivers/acpi/acpi_processor.c
>> ===================================================================
>> --- linux-pm.orig/drivers/acpi/acpi_processor.c
>> +++ linux-pm/drivers/acpi/acpi_processor.c
>> @@ -29,6 +29,9 @@
>>
>> ACPI_MODULE_NAME("processor");
>>
>> +DEFINE_PER_CPU(struct acpi_processor *, processors);
>> +EXPORT_PER_CPU_SYMBOL(processors);
>> +
>> /* --------------------------------------------------------------------------
>> Errata Handling
>> -------------------------------------------------------------------------- */
>> @@ -387,6 +390,7 @@ static int __cpuinit acpi_processor_add(
>> * checks.
>> */
>> per_cpu(processor_device_array, pr->id) = device;
>> + per_cpu(processors, pr->id) = pr;
>>
>> dev = get_cpu_device(pr->id);
>> result = acpi_bind_one(dev, pr->handle);
>> @@ -406,6 +410,7 @@ static int __cpuinit acpi_processor_add(
>> err:
>> free_cpumask_var(pr->throttling.shared_cpu_map);
>> device->driver_data = NULL;
>> + per_cpu(processors, pr->id) = NULL;
>> err_free_pr:
>> kfree(pr);
>> return result;
>>
>
> do you need to remove
> per_cpu(processors, pr->id) = NULL;
> from processor_driver.c::acpi_processor_stop ?

also can you kill per_cpu processors ?

You should always get it from
acpi_device from per_cpu(processor_device_array, cpu)
then driver_data from it.
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