Re: get_irq_regs() from soft IRQ

[Siarhei Siamashka <siarhei.siamashka@nokia.com>]

On Monday 29 June 2009 17:31:18 ext Jean Pihet wrote:
> Hi,
>
> I am trying to get the latest IRQ registers from a timer or a work queue
> but I am running into problems:
> - get_irq_regs() returns NULL in some cases, so it is unsuable and even
> causes crash when trying to get the registers values from the returned ptr
> - I never get user space registers, only kernel
>
> The use case is that the performance unit (PMNC) of the Cortex A8 has some
> serious bug, in short the performance counters overflow IRQ is to be
> avoided. The solution I am implementing is to read and reset the counters
> from a work queue that is triggered by a timer.

Regarding this oprofile related part. I wonder how you can get oprofile
working properly (providing non-bogus results) without performance
counters overflow IRQ generation? 

Are you trying to implement (in a clean way) something similar to
http://marc.info/?l=oprofile-list&m=123688347009580&w=2

Or is it going to be a different workaround?

-- 
Best regards,
Siarhei Siamashka

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