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SubjectRe: [v4.1.10-rt10][PATCH 1/2] genirq: introduce new generic_handle_irq_rt_wa() api
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Hi Thomas, Sebastian,

On 11/03/2015 10:18 PM, Sebastian Andrzej Siewior wrote:
> On 11/03/2015 08:51 PM, Thomas Gleixner wrote:
>>> where MAX_MSI_IRQS = 32 now, but potentially can be increased up to 256.
>>
>> And you really oversimplified the code above. The reality is:
>>
>> for (i = 0; i < MAX_MSI_CTRLS: i++) {
>> u32 status = read_msi_ctrl(i);
>>
>> for_each_bit(status)
>> handle_irq();
>> }
>>
>> So sure, the worst case here is MAX_MSI_CTRLS * 32, but if all
>> possible 256 MSI interrupts are pending at the same time, you have
>> other problems than that.
>
> With threaded interrupts we would have 256 invocations of
> wake_up_process() so nothing should take ages.
>

Thanks a lot for your time and comments - I'll follow your
recommendations and use IRQF_NO_THREAD.

--
regards,
-grygorii


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