When interrupt are globally disabled, interrupt are still detected and their flag set by their specific hardware circuit. It's only their immediat processing that are disabled.
After reenabling interrupt, they will be treated right away, as their flag are still set. it would looks like the interrupt trigger Just happened.
An interrupt miss is a problem if an interrupt is triggered a second time before the first one has been treated. That's When information is lost.
This is impossible in some case and harmless in other.
For the rest, the driver know something happens, but canot be sur of the number of triggers. As the interrupt are not lost, the driver's interrupt function is still called and has an opportunity to check it out, and act accordingly.
++
Le 21 mars 2016 08:11:54 GMT+01:00, Vishwas Srivastava <vishu.kernel@xxxxxxxxx> a écrit :
Kernel code heavily uses the spinlock primitives
spin_lock_irqsave/restore plus local interrupt disabling/ enabling, all across the code.
Is there a possibility that the interrupts might get
missed in this small window
disable interrupts
.............
............. <<<<<<<<<<<---------------------- interrupts is trigerred here
enable interrupts
specially when the irq
affinity has been set to the same core on which the
above mentioned code (disabling / enabling the irq's)
runs?
How the linux deals with this kind of scenario?
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