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* tick_setup_device in tick-common.c
@ 2011-07-01  9:49 chao xie
  2011-07-02  0:06 ` chao xie
  0 siblings, 1 reply; 2+ messages in thread
From: chao xie @ 2011-07-01  9:49 UTC (permalink / raw)
  To: linux-kernel

hi
I am very strange about this function.
In this function, it has
/*
         * When the device is not per cpu, pin the interrupt to the
         * current cpu:
         */
        if (!cpumask_equal(newdev->cpumask, cpumask))
                irq_set_affinity(newdev->irq, cpumask);

When the clock event device has cpu_mask set to be cpumask_of(1), it
means that the device is bound to cpu1. So above code has covered it,
but why we have "!cpumask_equal(newdev->cpumask, cpumask)"?
if the "newdev->cpumask" equals "cpumask", cpumask_equal will return
1, and at this situation we will set the irq affinity because the
device is bound to the dedicated cpu.

Is there a bug, or i understand wrong about cpumask of clock_event_device?
Thanks.

^ permalink raw reply	[flat|nested] 2+ messages in thread

* tick_setup_device in tick-common.c
  2011-07-01  9:49 tick_setup_device in tick-common.c chao xie
@ 2011-07-02  0:06 ` chao xie
  0 siblings, 0 replies; 2+ messages in thread
From: chao xie @ 2011-07-02  0:06 UTC (permalink / raw)
  To: linux-kernel

hi
I am very strange about this function.
In this function, it has
/*
        * When the device is not per cpu, pin the interrupt to the
        * current cpu:
        */
       if (!cpumask_equal(newdev->cpumask, cpumask))
               irq_set_affinity(newdev->irq, cpumask);

When the clock event device has cpu_mask set to be cpumask_of(1), it
means that the device is bound to cpu1. So above code has covered it,
but why we have "!cpumask_equal(newdev->cpumask, cpumask)"?
if the "newdev->cpumask" equals "cpumask", cpumask_equal will return
1, and at this situation we will set the irq affinity because the
device is bound to the dedicated cpu.

Is there a bug, or i understand wrong about cpumask of clock_event_device?
Thanks.

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2011-07-02  0:06 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
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2011-07-01  9:49 tick_setup_device in tick-common.c chao xie
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